JP2002199399A - Method and device for transforming moving vector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a moving vector transforming method capable of improving the efficiency of encoding by reducing movement retrieving processing in an MPEG4 image information encoding method which is the constitutional element of an image information transformation method even when the transformation scales of an image frame are optional scales in both horizontal and vertical directions. SOLUTION: In the moving vector transformation method for inputting 16×16 moving vectors of MPEG2 in a bit stream indicating the image compression information of the MPEG2 to be inputted and generating 8×8 moving vectors of MPEG4 and 16×16 moving vectors of MPEG4, the 8×8 moving vectors of MPEG4 and the 16×16 moving vectors of MPEG4 are generated from the 16×16 moving vectors of MPEG2 by space scaling and time base correction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bit stream showing image information compressed by orthogonal transform such as DCT (Discrete Cosine Transform) and motion compensation, such as MPEG, for example, satellite broadcasting, cable TV, the Internet, etc. Motion vector conversion method in image information conversion method and motion vector conversion in image information conversion apparatus used when receiving via a network medium or when processing on a storage medium such as an optical disk, a magnetic disk, or a flash memory Related to the device.

[0002]

2. Description of the Related Art In recent years, image information has been handled digitally, with the aim of transmitting and storing information with high efficiency.
Utilizing the redundancy inherent in image information, an apparatus that complies with a system such as MPEG, which compresses by orthogonal transform such as discrete cosine transform and motion compensation, can be used for both information distribution at broadcast stations and information reception at ordinary homes. Spreading.

In particular, MPEG2 (ISO / IEC 13
818-2) is defined as a general-purpose image coding method, and is a standard image coding method covering both interlaced scan images and progressive scan images, as well as standard resolution images and high-definition images, and is used for professional and consumer applications. It is expected to be used in a wide range of applications in the future.

By using the MPEG2 image compression method, for example, a standard resolution interlaced scan image having 720 × 480 pixels is 4 to 8 Mbps and 1920 × 1.
If a high-resolution interlaced scan image having 088 pixels is assigned a bit rate indicating a code amount of 18 to 22 Mbps, a high compression rate and good image quality can be realized.

[0005] The encoding system of MPEG2 mainly targets high-quality encoding suitable for broadcasting.
It does not correspond to a coding amount (bit rate) lower than G1, that is, a coding method with a higher compression ratio. With the spread of mobile terminals, it is expected that the need for such an encoding system will increase in the future, and in response to this, the MPEG4 encoding system has been standardized. Regarding the image coding method, 199
In December 2008, the standard was approved as an international standard as ISO / IEC 14496-2.

[0006] By the way, a bit stream indicating MPEG2 image compression information once encoded for digital broadcasting is more suitable for processing on a portable terminal or the like. There is a need to convert to a bitstream that represents information.

FIG. 1 shows a conventional image information conversion apparatus which achieves the above object. FIG. 1 shows a conventional example of an image information conversion apparatus that converts an input bit stream indicating MPEG2 image compression information into a bit stream indicating MPEG4 image compression information. That is, the input MPEG
The bit stream indicating the image compression information of MP2 is MP
The image is restored by the image decoding device 1 of EG2. The restored image signal is transmitted to the resolution / frame rate conversion device 2 and is converted into an image signal having any different resolution and frame rate. The converted image signal is MPEG
4 is encoded by the MPEG-4 image encoding system into a bit stream indicating MPEG4 image compression information and output.

As shown in FIG. 1, in a conventional image information conversion apparatus, an image signal restored by an MPEG2 decoding method is encoded by an MPEG4 image encoding apparatus, and a bit indicating MPEG4 image compression information is encoded. Output a stream. In the image information decoding apparatus 1 of MPEG2, the input MPE is used for both the horizontal and vertical components.
8th-order D of the bit stream indicating the image compression information of G2
It is conceivable to perform decoding processing using all of the CT (discrete cosine transform) coefficients. Although all the eighth-order coefficients are used in the vertical direction, among the eight-order coefficients in the horizontal direction,
Decoding processing using only the low-frequency four components (hereinafter referred to as 4 × 8 down-decoding) or decoding processing using only the low-frequency four components of the eighth-order coefficients in the horizontal direction both in the horizontal and vertical directions (Hereinafter, this is called 4 × 4 down decoding)
, The amount of calculation and the amount of video memory can be reduced while minimizing image quality degradation, and further down-sampling processing can be simplified.

In such a conventional image information conversion device,
In the MPEG4 image encoding apparatus, when encoding an input image signal, an operation processing amount for detecting a motion vector occupies about 60 to 70% of a total operation processing amount. As a result, it becomes difficult to process images in real time, causing a time delay, causing problems such as an increase in the size of the apparatus.

In order to solve such a problem, the present inventors have previously invented the image information conversion apparatus shown in FIG. Hereinafter, such an image information conversion apparatus will be described with reference to FIG. That is, in FIG.
, A resolution / frame rate converter, 6 a motion vector converter, and 7 an MPEG4 image information encoder.

FIG. 3 is a conceptual diagram showing a correlation between a motion vector in a bit stream indicating MPEG2 image compression information and a motion vector in a bit stream indicating MPEG4 image compression information. When the resolution of the image is converted, the horizontal component of the motion vector from the position in the previous frame after the conversion to the position in the current frame is obtained by converting the horizontal component of the motion vector before the resolution conversion into the horizontal resolution of the image. It can be determined by the rate.

The vertical component after resolution conversion is obtained from the vertical component of the motion vector before resolution conversion and the vertical resolution conversion rate of the image. That is, the motion vector before the resolution conversion and the motion vector after the conversion have a large correlation. By utilizing the correlation, a motion vector after the conversion can be obtained from the motion vector before the resolution conversion.

That is, a motion vector of an MPEG2 macroblock or a parameter such as a macroblock type is used from a bit stream indicating MPEG2 image compression information, and the motion vector is simply converted to an MPEG4 motion vector. In the MPEG4 encoding device 7, the motion vector is not detected and the image encoding using the converted motion vector is performed. As a result, MPEG
Since no motion detection is performed in the image encoding device of No. 4, the processing amount is greatly reduced.

As described above, the conversion from the MPEG2 motion vector to the MPEG4 motion vector is performed. In addition to the motion vector, the parameters used for decoding in MPEG2 or the parameters after the conversion are adopted. The time delay can be reduced by reducing the processing amount of the MPEG4 encoding device.

In FIG. 2, an input bit stream indicating MPEG2 image compression information is subjected to a decoding process in an MPEG2 image decoding device 4. MP
In the image information decoding device 4 of EG2, it is conceivable to perform a decoding process using all the 8th-order DCT coefficients of the bit stream indicating the input MPEG2 image compression information in both the horizontal and vertical components. By performing 4 × 8 down-decoding or 4 × 4 down-decoding, it is also conceivable to reduce the amount of calculation and the video memory capacity while minimizing image quality degradation, and to further simplify down-sampling processing in the subsequent stage. .

An image output from the decoding device 4 is sent to a resolution / frame rate conversion device 5 and subjected to resolution / frame conversion. After that, it is suitable for MPEG4 image encoding by an externally input image size adjustment flag. An image having the same resolution is output.

The resolution frame rate converter 5 first converts the resolution of the image input from the MPEG2 image decoder 4. Here, the resolution is 1 for both the vertical and horizontal directions.
/ 2 is taken as an example. As shown in FIG. 4, in the vertical downsampling, the first field or the second field of the input interlaced scan image is extracted and converted into a progressive scan image. In the horizontal direction, the resolution is converted to 1/2 resolution using a downsampling filter. In addition, in order to realize a low bit rate, not only compression by resolution conversion, but also a first field or a second field of only I / P pictures is extracted, and the frame rate is reduced in the time direction.

For example, the IB of MPEG2 shown in FIG.
After the resolution / frame conversion, the BPBB image has the first field configuration of the IPPP. Both the vertical and horizontal pixels are set to multiples of 16 so that the resolution-frame converted image can be encoded by the MPEG4 image encoding method. Therefore, pixels are supplemented or pixels are removed according to an image size adjustment flag input from the outside.

The image size adjustment flag is input from the outside of the resolution / frame rate converter, and is used to determine whether the image is supplemented or removed from the image when the number of vertical and horizontal pixels is not a multiple of 16. Flag.

Next, processing on an image by the image size adjustment flag will be described with reference to FIG. Assuming that the resolution of the image output from the MPEG2 image decoding device 4 is m pixels × n pixels, both m and n are multiples of 16,
M / 2, n / downsampled to 1/2 length and width
2 has an integer multiple of 16 or a remainder of 8 pixels when divided by 16. It is determined whether or not both m / 2 and n / 2 are multiples of 16. If both m / 2 and n / 2 are multiples of 16, an image suitable for the encoding method of MPEG4 is obtained. Therefore, no processing is performed on the image. Also, m
If both / 2 and n / 2 are not a multiple of 16, MPEG
Therefore, it is necessary to process an image using an image size adjustment flag.

The image size adjustment flag has two options of pixel compensation and pixel removal. m / 2 or n / 2 is 1
If there are eight pixels left after dividing by 6, if the removal of the image is selected, the remaining eight pixels are removed. That is,
The output image is (m / 2-8) or (n / 2-8). On the other hand, if pixel complementation is selected, eight pixels newly created, eight pixels copied from the original image, or eight pixels suitable for the image are added from the top or the rear of the row or column. That is, the output image is (m / 2 + 8) or (n / 2 + 8). As a result, the width and height of the converted image resolution are multiples of 16, and an image having a size suitable for the MPEG4 encoding method is output.

On the other hand, the input bit stream indicating the MPEG2 image compression information is subjected to variable-length code decoding by the MPEG2 image decoding device 4 and then to a motion vector or a macroblock of a macroblock including only P pictures. Other parameters such as the block type are extracted and transmitted to the motion vector converter 6.

The motion vector conversion method in the motion vector conversion device 6 will be described with reference to FIG. Each of the square lattices separated by a solid line in FIGS. 6A and 6B indicates a macroblock. FIG. 6A shows MPEG2
, Ie, an image before resolution conversion. FIG. 6B shows an image obtained by converting the image of FIG. 6A to half in both the vertical and horizontal resolutions by the resolution / frame rate conversion device 5. For example, a 16 × 16 macroblock shaded in the upper left of FIG. 6A before conversion is an 8 × 8 block shaded in the upper left in FIG. 6B after the conversion. That is, 4 shown in FIG.
Each of the 16 × 16 shaded macroblocks, after resolution conversion, becomes four shaded 8 × 8 blocks, each shown in FIG.
A 6 × 16 macro block is configured. Since the correlation between the motion vector before and after the resolution conversion is large, the converted 8 ×
The motion vector of the 8 block can be obtained from the motion vector of the 16 × 16 macro block before the conversion. Further, one 16 × 16 motion vector is determined from the four 8 × 8 motion vectors, and the 4 × 16 motion vector used for encoding by the MPEG4 image encoding method is obtained.
Two 8 × 8 motion vectors and one 16 × 16 motion vector are generated.

FIG. 7 shows a detailed configuration of the motion vector conversion device 6. Referring to FIG.
The operation principle of will be described. The parameters such as the motion vector and the image size in the bit stream indicating the input MPEG2 image compression information are supplied to the MPEG2 16 × 16 motion vector → MPEG4 8 × 8 motion vector conversion device 70, Vector conversion is performed to create an 8 × 8 motion vector before correction.

In the macro block information buffer 73, the MP
The motion vector information, macroblock mode, quantization scale, and bit amount of the macroblock of EG2 are stored. The adjuster 71 for the motion vector based on the image size adjustment flag adjusts the image size after conversion to a multiple of 16 based on the method described with reference to FIG. The motion vector corrector 72 for the MPEG2 intra macroblock substitutes the motion vector of the macroblock encoded by the peripheral inter macroblock into the motion vector value converted from the MPEG2 intra macroblock.
In the MPEG4 8 × 8 → 16 × 16 motion vector converter 74, a representative motion vector is determined from the 8 × 8 motion vectors of four 8 × 8 blocks constituting one MPEG4 macroblock. And 16 × 1
6 motion vectors.

FIG. 8 shows a 16 × 16 motion vector of MPEG2 → 8 × 8 motion vector converter 6 of MPEG4.
The operation principle of the motion vector conversion device 6 will be described with reference to FIG.

The input MPEG2 macroblock motion vector and the macroblock type are compared with the MPEG2 macroblock motion vector.
The 2 × 16 × 16 motion vector → MPEG4 8 × 8 motion vector converter 6 operates as follows. Since a frame structure is generally used in a bit stream indicating MPEG2 image compression information of interlaced scanning, a conversion method only for processing in the case of a frame structure will be described this time.

At step ST-1, it is determined whether the macroblock type is intra / inter / skip. If it is determined in step ST-1 that the macroblock type is an intra macroblock, the MPEG2 intra macroblock assumes that the 8 × 8 block after resolution conversion has a motion vector. , The processing of step ST-2 is performed.
As the processing, first, an 8 × 8 motion vector is set to 0, and an intra mode flag is provided for the processing by the corrector 72. In MPEG2, if the block is an intra macro block, an intra mode flag is set (provided).

If it is determined in step ST-1 that the macroblock type is a skip macroblock, the motion vector of each block is set to 0 in step ST-3. Note that skip means MPEG2
, The macroblock mode means that the motion vector is (0,0) and no discrete cosine transform coefficient bits are generated.

If it is determined in step ST-1 that the macroblock type is an inter macroblock, then in step ST-4, frame / field prediction is determined. If the image has a frame structure and frame prediction for the inter macroblock, conversion to a motion vector suitable for frame prediction is performed as shown in step ST-5. This motion vector conversion will be described with reference to the conceptual diagram of FIG. FIG.
As described above, the horizontal component of the motion vector after conversion is obtained from the horizontal component of the motion vector before conversion and the horizontal resolution conversion rate of the image. The vertical component is obtained from the vertical component of the motion vector before conversion and the vertical resolution conversion rate of the image. That is, when the resolution in the horizontal direction is converted to １ ／, the horizontal component of the converted motion vector also becomes の before the conversion. When the resolution in the vertical direction is converted to １ ／, the vertical component of the converted motion vector also becomes の before the conversion.

For example, the motion vector shown in FIG.
(8, 12) before the conversion in FIG. 9A becomes (4, 6) after the conversion in FIG. 9B. In this case, the interval between the intermediate values (half pixels) of the integer pixels is set to 1. In the figure before the resolution conversion in FIG. 9A, black circles indicate positions of integer pixels, and diamonds indicate positions of half pixels. In the figure after the resolution conversion in FIG. 9B, white circles indicate half pixels. As can be seen from the figure, the motion vector shown at the position of the integer pixel before conversion in FIG. 9A is shown at the position of the integer pixel or half pixel after conversion in FIG. In the motion vector shown at the pixel position, there is no pixel to be referred after the resolution conversion in FIG. 9B. Therefore, when the motion vector before conversion in FIG. 9A indicates the position of a half pixel, FIG.
The motion vector after the conversion is set to indicate the position of a half pixel of the predicted image.

This is because the decoded image signal originally contains distortion due to quantization, so that if it is used as a predicted image as it is, the prediction efficiency will be reduced and image quality will be degraded. To reduce this,
In some cases, half-pixel accuracy is obtained by linearly interpolating 1: 1 between pixels on a reference screen corresponding to a low-pass filter, thereby avoiding image quality degradation. Therefore, in order to improve the prediction efficiency and prevent the image quality from deteriorating, the encoding by the MPEG4 image encoding method is performed in the case where the motion vector is indicated by a half pixel position in MPEG4.
4 is also converted as shown at the position of a half pixel. The correspondence between the motion vectors before and after the conversion is as shown in the table of FIG.

Next, when it is determined in step ST-1 that the macroblock type is an inter macroblock, in step ST-4, it is determined which of frame / field prediction is to be performed. . If the image has a frame structure and is a field prediction, step S
At T-6, the first field prediction / second field prediction is determined. First, when it is determined that it is the first field prediction, as shown in step ST-7, the field prediction is converted into a motion vector suitable for the first field prediction. This will be described with reference to a conceptual diagram of FIG. The horizontal component of the motion vector is subjected to the same processing as described above with reference to FIG. In the vertical direction, it is possible to convert the resolution to に よ り by extracting the first field. In addition, since the first field prediction is also performed in the prediction, the motion vector before the conversion becomes the motion vector after the conversion as it is.

If it is determined in step ST-6 that it is the second field prediction, as shown in step ST-8, the field prediction is converted into a motion vector suitable for the second field prediction. The motion vector conversion in that case will be described with reference to the conceptual diagrams of FIGS. At the time of resolution conversion, only the first field is extracted. Therefore, after the conversion, the pixel value of the first field is used as a reference image. Therefore, spatio-temporal correction of the motion vector is performed so that the pixel value of the second field used as the prediction image in MPEG2 is converted into the first field prediction after resolution conversion.

FIG. 12 is a diagram showing a method for performing spatial correction for approximately converting the second field prediction to the first field prediction. That is, 1 is added to the vertical component of the motion vector. As can be seen from the figure, when 1 is added to the vertical component of the motion vector obtained in the second field prediction, one row is moved up, so that the second field reaches the same spatial position as the first field, and , The motion vector obtained in the first field prediction. Equation 1 represents the vertical component of the motion vector MV _top when the second field at the same spatial position as the first field, that is, the approximate first field is predicted by the spatial correction.

[0036]

## EQU1 ## Linear component: approximate MV _top = MV _bottom +1

The interlaced MPEG2 image compression information has a time lag between the first field and the second field. Therefore, the time lag between the first field approximated from the second field and the actual first field is corrected.

FIG. 13 shows the temporal positional relationship of each field. Here, the interval between the first field and the second field is set to 1, and a is defined as
Assuming an interval between the first field and the picture, a is an odd number such as 1, 3, 5, 7,. Note that a is 1
Is a case where the image configuration is IPPP. The time-corrected motion vector MV ′ is shown in Expression 2.

[0039]

## EQU2 ## Vertical component: MV '= {(a + 1) / a} approximation MV _top

When the equation (1) is substituted into the equation (2), the vertical component of the converted motion vector becomes the equation (3).

[0041]

## EQU3 ## Vertical component: MV '= {(a + 1) / a} (MV
_bottom +1)

The horizontal component of the converted motion vector is
The motion vector before conversion is multiplied by (a + 1) / a, and after performing temporal correction, the motion vector is obtained according to the calculation in the table of FIG.

If necessary, the vertical component of the motion vector may be temporally corrected and then spatially corrected. In this case, the vertical component of the motion vector MV 'is expressed by Equation 4.
Is shown in the following equation. The horizontal component has the same value in the space / time correction (time correction is performed after the space correction is performed) and the time / space correction (space correction is performed after the time correction is performed).

[0044]

## EQU4 ## Vertical component: MV ′ = ｛(a + 1) / a｝ MV _bottom +1

The difference between the formulas (3) and (4), that is, the difference between the vertical component of the motion vector when the space / time correction is performed and the time / space correction is 1 / a. . Therefore, the influence of the difference differs depending on the value of a. Therefore, when a is 1, it is larger than 1, that is, 3, 5,
The correction method in the two cases of 7 and ‥‥ will be described below.

First, the case where a = 1 will be described. That is, when 1 is substituted for a in the equation (3), the vertical component of the motion vector becomes the equation (5).

[0047]

## EQU5 ## Vertical component: MV '= 2.times. (MV _bottom +1)

When 1 is substituted for a in equation (4), the vertical component of the motion vector is as shown in equation (6).

[0049]

## EQU6 ## Vertical component: MV '= 2.times.MV _bottom +1

As a result, the motion vector MV before conversion
By substituting 0, 1, 2, ‥‥ into the _bottom , the value according to the equation of Equation 5 becomes an even number such as 2, 4, 6, ‥‥. That is, when the space / time correction is performed, the motion vector before the conversion may be shown at the position of an integer pixel or at the position of a half pixel,
After conversion, they are all shown at integer pixel positions. Further, the value obtained by the equation (6) is an odd number such as 1, 3, 5,. That is, when the time / space correction is performed, the motion vector before the conversion may be shown at the position of the integer pixel or at the position of the half pixel,
After conversion, they are all shown at half-pixel positions.

Therefore, if the motion vector indicated at the position of the integer pixel before the conversion is to be indicated at the position of the integer pixel even after the conversion, space / time correction is performed. When the motion vector indicated at the half-pixel position before the conversion is indicated at the half-pixel position after the conversion, time / space correction is performed. That is, spatial correction and temporal correction are alternately used for the motion vector before conversion, and the motion vector is converted to a motion vector after resolution conversion, or all the time and space correction are performed for the motion vector before conversion.

After the above-described motion vector conversion processing is completed, an MPEG4 8 × 8 motion vector before correction is output. The output 8 × 8 motion vector is transmitted to the motion vector adjuster 71 based on the image size adjustment flag, and outputs a motion vector suitable for the image size according to the image size adjustment flag input from the outside.

The adjustment of the motion vector to the motion vector by the image size adjustment flag in the adjuster 71 will be described with reference to the conceptual diagram of FIG. If both m / 2 and n / 2 are multiples of 16 for an input image having an image size of m × n pixels, the MPEG4 8 × 8 motion vector output from the motion vector converter 70 is The data is output as it is without being processed by the adjuster 71.

When either m / 2 or n / 2 is not a multiple of 16, the image size adjustment flag input from the outside is used. In the case of pixel removal, 8 × 8 pixels of the removed 8 pixels are used.
Is output, another 8 × 8 motion vector is output. In the case of pixel compensation, the 8 × 8 motion vector of the supplemented eight pixels is set to 0, and output together with the other input 8 × 8 motion vectors.

Returning to FIG. 7, the description will be continued. The 8 × 8 motion vector suitable for the image size output from the adjuster 71 for the motion vector based on the image size adjustment flag is M
8 × 8 motion vector of PEG4 → 16 × of MPEG4
It is converted by 16 motion vector converters 74.

The MPEG4 8 × 8 motion vector → MPEG4 16 × 16 motion vector converter 74 shown in FIG.
Is a 16 × 16 motion vector of MPEG2 →
MPEG4 for the macro block generated in the MPEG4 8 × 8 motion vector converter 70
Of the 8 × 8 motion vectors, a vector generated from a macroblock considered to have the highest encoding efficiency is selected and output as a 16 × 16 MPEG4 motion vector.

The coding efficiency is determined based on information for each macroblock in a bit stream stored in the macroblock information buffer 73 and indicating MPEG2 image compression information input to the image information converter.

That is, the first method is a method in which the macroblock having the least non-zero DCT coefficient among the four macroblocks has high coding efficiency. The second method is a method in which, out of the four macroblocks, the macroblock having the smallest number of bits allocated to the DCT coefficient of the luminance component has high encoding efficiency. The third method is a method in which, out of the four macroblocks, the macroblock with the smallest number of bits allocated to the DCT coefficient has high coding efficiency. The fourth method is
In this method, among the four macroblocks, the macroblock having the smallest total number of bits, including the motion vector and the like, allocated to the macroblock has high encoding efficiency. The fifth method is a method in which, out of the four macroblocks, a macroblock having the smallest assigned quantization scale has high coding efficiency. The sixth method is a method in which a macroblock having the lowest complexity among the four macroblocks has high coding efficiency. The complexity X assigned to each macroblock is calculated using the quantization scale Q and the number of bits B assigned to the macroblock as in the following equation (7).

[0059]

X = Q · B

The number of bits B in this equation may be the number of bits assigned to the entire macroblock, the number of bits assigned to DCT coefficients, or the number of bits assigned to DCT coefficients assigned to luminance components. But it is good.

On the other hand, an 8 × 8 motion vector suitable for the image size output from the motion vector adjuster 71 based on the image size adjustment flag is input to a motion vector corrector 72 for an MPEG2 intra macroblock. Therefore, in the bit stream indicating the image compression information of MPEG2, the 8 × 8 motion vector of the block converted from the intra-macro block is expressed by MP
8 × 8 motion vector of EG4 → 16 × 1 of MPEG4
16 obtained by the motion vector converter 74 of FIG.
It is replaced with a × 16 motion vector and corrected.
The corrected 8 × 8 motion vector and the MPEG4 8 × 8
And the 16 × 16 motion vector obtained by the 16 × 16 motion vector converter 74 of MPEG4 are output as a motion vector of MPEG4.

[0062]

In FIG. 7, the motion vector conversion device of which the detailed configuration has been described is an 8 × 8 motion vector of MPEG4 → a 16 × 16 motion vector conversion device 74 of MPEG4. 1
By selecting a representative value of the MPEG4 8 × 8 motion vector output from the MPEG4 8 × 8 motion vector conversion device 70, the MPEG4 16 × 8
Sixteen motion vectors have been generated.

However, when the motion vector of MPEG2 is converted into MPEG4, the image frame size is converted to an arbitrary magnification. However, there is no problem that there is no means for converting the motion vector in the conversion of the image frame size. Have.

In view of the above, the present invention provides an image information conversion method in which a bit stream indicating MPEG2 image information compression information of interlaced scanning is input and a bit stream indicating MPEG4 image compression information of progressive scanning is output. In the motion vector conversion method which is a component, even if the conversion magnification of an image frame is an arbitrary magnification in both the horizontal and vertical directions, the motion search processing in the image information encoding method of MPEG4 which is a component of the image information conversion method And propose a method that can increase the coding efficiency.

The present invention also relates to an interlaced MPEG
In the motion vector conversion device which is a component of the image information conversion device which receives the bit stream indicating the image information compression information of No. 2 as input and outputs the bit stream indicating the compression image data of progressive scanning MPEG4, Proposes a system that can reduce the motion search processing in the MPEG4 image information encoding device, which is a component of the image information conversion device, and increase the encoding efficiency even if the horizontal and vertical directions are both arbitrary magnifications. What you want to do.

[0066]

According to a first aspect of the present invention, a bit stream indicating MPEG2 image compression information of interlaced scanning is input, and progressive scanning MPEG4 image compression information obtained by converting an image frame size to an arbitrary magnification is shown. In the motion vector conversion method in the image information conversion method in which the bit stream is output, the MPEG2 16 × 1 in the bit stream indicating the input MPEG2 image compression information
6 is a motion vector conversion method for generating an 8 × 8 motion vector of MPEG4 and a 16 × 16 motion vector of MPEG4 by using as input a motion vector of MPEG2.
This is a motion vector conversion method in which an 8 × 8 motion vector of MPEG4 and a 16 × 16 motion vector of MPEG4 are generated from the 16 × 16 motion vector of the above by spatial scaling and time axis correction.

The second invention is an MPEG2 interlaced scan.
In the image information conversion method of inputting the bit stream indicating the image compression information of the input and outputting the bit stream indicating the image compression information of the progressive scanning MPEG4 in which the image frame size is converted to an arbitrary magnification, the image compression of the input MPEG2 is performed. MPEG2 1 in the bit stream indicating information
A motion vector of 6 × 16 is input and 8 × of MPEG4
8 is a motion vector conversion method for generating a motion vector of 8 and a 16 × 16 motion vector of MPEG4.
8 × of MPEG4 generated by spatial scaling and time axis correction from 16 × 16 motion vector of EG2
When generating a 16 × 16 motion vector of MPEG4 from the 8 motion vectors, the coding efficiency of the encoding efficiency is higher than that of the 8 × 8 motion vectors of four 8 × 8 blocks constituting one MPEG4 macroblock. 8 considered high
A motion vector conversion method characterized by selecting a × 8 motion vector and using the selected motion vector as a 16 × 16 MPEG4 motion vector.

The third invention relates to interlaced MPEG2
A motion vector conversion device in an image information conversion device, which receives a bit stream indicating image compression information of an input and outputs a bit stream indicating image compression information of progressively scanned MPEG4 obtained by converting an image frame size to an arbitrary magnification,
An MPEG2 16 × 16 motion vector in a bit stream indicating MPEG2 image compression information to be input is input, and an MPEG4 8 × 8 motion vector and M
A motion vector conversion device for generating a 16 × 16 motion vector of PEG4, comprising spatial scaling and time axis correction means, and converting the 16 × 16 motion vector of MPEG2 to a MPEG4 by a spatial scaling and time axis correction means. 8x8 motion vector and MPEG4
This is a motion vector conversion device that generates a 16 × 16 motion vector.

A fourth aspect of the present invention relates to interlaced MPEG2
In the image information conversion apparatus which receives the bit stream indicating the image compression information of the input and outputs the bit stream indicating the image compression information of the progressive scanning MPEG4 in which the image frame size is converted to an arbitrary magnification, the image compression of the input MPEG2 is performed. MPEG2 1 in the bit stream indicating information
A motion vector of 6 × 16 is input and 8 × of MPEG4
A motion vector conversion device for generating a motion vector of 8 MPEG-8 and a 16 × 16 motion vector of MPEG4, comprising: a spatial scaling and time axis correcting means;
Selecting means for selecting an 8 × 8 motion vector considered to have the highest encoding efficiency from among the 8 × 8 motion vectors of the four 8 × 8 blocks constituting the macro block of MPEG2. From the × 16 motion vectors, the spatial scaling and time axis correction means
4 8 × 8 motion vector and MPEG4 16 × 16
When the motion vector is generated by the motion vector conversion device, the selecting unit selects the 8 × 8 motion vector considered to have the highest encoding efficiency as the 16 × 16 motion vector of MPEG4. is there.

[0070]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an example of a motion vector conversion method and a conversion apparatus according to an embodiment of the present invention will be described with reference to the drawings. First, referring to the conceptual diagram of FIG.
A method of converting the motion vector information in the bit stream of FIG.

First, a description will be given of a method of converting MPEG4 into 8 × 8 motion vectors. As shown in FIG. 14, since the image frame size is converted at an arbitrary magnification (a / b times in the horizontal direction and c / d times in the vertical direction), M shown in black is used.
The range of the PEG2 image corresponds to the range of an 8 × 8 block of MPEG4. In this case, since the conversion magnification of the image frame is an arbitrary magnification, the range aligned with the boundary of the MPEG2 macroblock does not correspond to the 8 × 8 block of MPEG4.

The motion vector conversion method will be described with reference to the conceptual diagram of FIG. The range on the MPEG2 image corresponding to the MPEG4 macroblock is indicated by black painting. In the example of FIG. 15, 8 × 8 of MPEG4
The macro block of MPEG2 that overlaps the block of
A range of one-fourth of B0 to MB15, that is, MPEG
MP that overlaps the range corresponding to 8 × 8 block 0 of 4
The EG2 macroblocks are MPEG2 macroblocks MB0, MB1, MB4 and MB5. With respect to the four MPEG2 macroblocks, the macroblock mode of the MPEG2 macroblock included in the MPEG2 bit stream is extracted.

When a macroblock determined to be skipped among the four overlapping macroblocks is included, the motion vector of the output MPEG4 is set to (0,
0). The skip means that the motion vector is (0,
0), which means that no DCT (discrete cosine transform) coefficient bits are generated.

If there is no skipped macroblock among the four overlapping macroblocks, it is determined whether or not a macroblock whose macroblock mode is NotCoded is included. Note that NotCoded is DC2 in the syntax of MPEG2.
A macroblock mode of a macroblock in which no T coefficient bit occurs. When a plurality of NotCoded macroblocks are included, the lengths of the motion vectors are compared, and a motion vector of a macroblock having a shorter motion vector is selected. Thus, the output motion vector is
It is converted from the motion vector of the NotCoded macroblock.

If the skipped macroblock and the NotCoded macroblock do not exist among the four overlapping macroblocks, the macroblock mode is No.
It is determined whether or not an MC macro block is included. NoMC is the syntax of MPEG2 (syn
tax) means a macroblock mode of a macroblock whose motion vector is (0, 0). . NoM
When a plurality of C macroblocks are included, a motion vector of a macroblock having a smaller amount of coding bits is selected. Thereby, the motion vector of the output MPEG4 is set to (0, 0).

As described above, the macroblock mode is skipped,
The processing in the case of NotCoded and NoMC has been described,
The above-described determination in the macroblock mode may be omitted, and the processing may be performed by arbitrarily combining them.

Next, four MPEG-4 images overlapping an MPEG2 image area corresponding to an 8 × 8 block of MPEG4
Skip to the macro block of No.2, NotCode
If the macroblock mode of d, NoMC is not included, the coding bit amounts B0, B1, B4, and B5 and the coding quantization scales Q0, Q1, Q4, and Q5 are extracted.

The number of pixels (area) A0, A1, A4 overlapping the range corresponding to the 8 × 8 block of MPEG4
And A5 are calculated. In each of the MPEG2 macroblocks, the parameter X is obtained by the following equation (8).

[0079]

(Equation 8)

A macroblock having the largest value of the parameter X is selected, and the motion vector of this macroblock is converted into an MPEG4 8 × 8 motion vector. The value of the parameter X increases as the number of pixels overlapping the range corresponding to the 8 × 8 block of MPEG4 increases, the macroblock coding efficiency increases, and Q × B decreases. Therefore, the overlapping range is wide, the contribution rate to the range corresponding to the 8 × 8 block is the highest, the prediction accuracy of the motion vector is high, and the coding complexity Q ×
When B is low, it is possible to select a motion vector with the highest encoding efficiency in the overlapping range. That is, a motion vector of a macroblock in which the value of the parameter X is the maximum value is selected, and this is spatially and temporally corrected to generate an MPEG4 motion vector.

Hereinafter, an example of an image information conversion device including the motion vector conversion device according to the embodiment of the present invention will be described with reference to FIG. MPEG2 decoding device 160
Outputs MPEG2 encoded images, MPEG2 motion vector information and macroblock mode information.
The MPEG2 motion vector and macroblock mode buffer 161 stores MPEG2 motion vector information and macroblock mode information. The reference macroblock calculation device 167 calculates an MPEG2 macroblock address that overlaps a pixel range corresponding to an MPEG4 8 × 8 block and a 16 × 16 macroblock. As described above, the combined vector determination device 162
One motion vector is selected from macroblocks overlapping a range corresponding to a PEG4 8 × 8 block.

The selected MPEG2 motion vector is input to an 8 × 8 motion vector space / time correction device 163, which converts the motion vector into an MPEG4 motion vector based on the prediction mode. That is, when the motion compensation prediction mode is frame prediction,
The motion vector of MPEG2 is reduced in the vertical and horizontal directions by a designated arbitrary scale of image frame conversion. In the case where the motion vector of MPEG2 is field prediction and the reference field is the first field, only the vertical component of the motion vector is normalized to twice, and then the vertical / horizontal conversion is performed at an arbitrary magnification of the specified image frame conversion. Scaled down.

The motion prediction mode is field prediction,
When the reference field is the second field, the motion vector is first added with a correction of one line in the vertical direction (half a pixel in one field) for field correction,
Next, in order to extract only the first field by one-field thinning, multiply (a + 1) / a in order to correct the field interval between the discarded reference second field and the first field in the same frame. . In this expression, a means a field interval between the field and the reference second field. However, when the conversion of the image frame size is 1/2 or more, such as 2/3 in the vertical and horizontal directions, the field / time (interval) correction is performed because there is a possibility that the one-field discarding technique may not be used. You don't have to. Further, the vertical direction of the motion vector is normalized to twice, and reduced in the vertical and horizontal directions by the specified magnification of the image frame conversion.
Output the motion vector of G4.

The MPEG4 8 × 8 motion vector scaled by the spatial / temporal correction is then input to the 8 × 8 motion vector re-searching device 164, and is generated in the MPEG4 image converted at an arbitrary magnification. MPEG4
Is re-searched around the 8 × 8 motion vector. The range of the re-search is arbitrary. In this case, if the re-search range is ± 2 pixels as an integer pixel, the search processing can be significantly reduced compared to the ± 15 motion search processing in a full search specified in a normal VM or the like. .

The 8 × 8 motion vector re-searching device 164 also calculates the residual obtained from the zero motion vector.
The motion vector converted by arbitrary weighting is compared with a residual value obtained by a peripheral search. If the value obtained by subtracting the weight from the residual component of the zero motion vector is smaller than the converted motion vector, the output MPEG-4 motion vector is output as a zero motion vector. This allows MP
The number of macroblocks determined to be skipped macroblocks in the EG4 bit stream increases, and the coding efficiency increases. Note that MV is a verification model (Verification M) for encoding verification of MPEG4 defined by MPEG.
odel).

The 8 × 8 motion vector and the residual value obtained by the re-search processing are input to an 8 × 8 → 16 × 16 motion vector selecting device 165, and four 8 × 8 blocks constituting a macro block The motion vector with the smallest prediction residual among the motion vectors is selected and assigned to a 16 × 16 motion vector. Next, the 16 × 16 motion vector re-search device 166 searches again in the small range around the 16 × 16 motion vector selected, thereby improving the coding efficiency of the 16 × 16 motion vector. Also in the 16 × 16 motion vector re-searching device 166, the residual component is calculated based on the zero motion vector in the same manner as in the 8 × 8 motion vector re-searching device 164, and it is determined that the residual component of the zero motion vector is the smallest by weighting. Output 16x
The 16 motion vectors are assumed to be zero motion vectors.

Thus, the MPEG4 8 × 8 and 16 ×
The 16 motion vectors are generated, input to the MPEG4 encoding device 169 together with the image whose image frame has been converted to an arbitrary scale by the image frame conversion filter 168 having an arbitrary scale, and the device 169 outputs an MPEG4 bit stream.

Referring to FIG. 17, another example of the image information conversion apparatus including the motion vector conversion apparatus according to the embodiment of the present invention will be described. The MPEG2 decoding device 170 decodes MPEG2 bit stream information and outputs MPEG2 decoded images, MPEG2 motion vector information, and macroblock mode information. The synthesized vector determination device 172 determines a macroblock overlapping a range corresponding to the 8 × 8 and 16 × 16 motion vectors, and determines whether the macroblock is an 8 × 8 motion vector selection device 173 or a 16 × 16 motion vector selection device. Each is input to the device 177. The method of generating the 8 × 8 motion vector is processed in the same manner as described with reference to FIG.
In the case of the × 16 motion vector, the MPEG2 frame MPEG2
The motion vector is selected from macroblocks overlapping the range corresponding to the macroblock in the VOP (Video Object Plane) of No. 4 and MPEG4 16
Generate a × 16 motion vector. This allows MPEG
4 8 × 8 and 16 × 16 motion vectors are generated,
MPEG4 encoding device 171 together with an image whose image frame has been converted to an arbitrary scale by frame conversion filter 1710 for an arbitrary scale image
1 and outputs an MPEG4 bit stream.

As described above, the bit stream indicating the image compression information of MPEG2 as the input and the bit stream indicating the image compression information of MPEG4 as the output have been described. However, the input and output are not limited to this.
And H. A bit stream indicating image compression information such as H.263 may be used.

[0090]

As described above, according to the present invention,
In a motion vector conversion method which is a component of an image information conversion method in which a bit stream indicating MPEG2 image information compression information of interlaced scanning is input and a bit stream indicating MPEG4 image compression information of progressive scanning is output, Even if the conversion magnification of the horizontal direction and the vertical direction is arbitrary, the motion vector information and the macroblock information of MPEG2 are used to improve the encoding efficiency of MPEG.
By selecting 48 × 8 and 16 × 16 motion vectors, it is possible to reduce the motion search processing in the MPEG4 image information encoding method, which is a component of the image information conversion method, and increase the encoding efficiency. Can be obtained.

Further, according to the present invention, the interlaced scanning M
In a motion vector converter, which is a component of an image information converter that receives a bit stream indicating PEG 2 image information compression information and outputs a bit stream indicating progressively scanned MPEG 4 image compression information, the image frame conversion magnification Even if the horizontal and vertical directions are both arbitrary magnification,
Using the motion vector information and macroblock information of MPEG2, MPEG48 × 8 and 16
By selecting the × 16 motion vector, it is possible to reduce the motion search processing in the MPEG4 image information encoding device, which is a component of the image information conversion device, and obtain an image information encoding device capable of improving encoding efficiency. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing a conventional image information conversion apparatus which realizes conversion from a bit stream indicating MPEG2 image compression information to a bit stream indicating an MPEG4 image information compression apparatus.

FIG. 2 is a block diagram showing an image information conversion apparatus which is invented by the inventors of the present application and converts a bit stream indicating MPEG2 image compression information to a bit stream indicating an MPEG4 image information compression apparatus. FIG.

FIG. 3 is a conceptual diagram showing a correlation between a motion vector in a bit stream indicating MPEG2 image compression information and a motion vector in a bit stream indicating MPEG4 image compression information.

FIG. 4 is an explanatory diagram showing an operation principle of resolution / frame rate conversion of the resolution / frame rate conversion device 5 in FIG. 2;

FIG. 5 is an explanatory diagram showing an operation principle of pixel supplement or removal according to an image frame size adjustment flag of the resolution / frame rate conversion device 5 in FIG. 2;

FIG. 6 is an explanatory diagram showing a motion vector conversion method of the motion vector conversion device 6 in FIG.

FIG. 7 is a block diagram showing a detailed configuration of a motion vector conversion device 6 in FIG. 2;

FIG. 8 shows a 16 × 16 motion vector of MPEG2 → 8 × 8 motion vector converter 8 of MPEG4 in FIG.
6 is a flowchart showing the operation of the first embodiment.

9 is a 16 × 16 motion vector of MPEG2 → 8 × 8 motion vector converter 7 of MPEG4 in FIG. 7;
It is a conceptual diagram which shows the motion vector conversion in the case of the frame structure at 0, and a frame prediction.

10 shows a half-pixel precision motion vector in a bit stream indicating MPEG2 image compression information in FIG. 9;
FIG. 4 is a table showing handling after conversion into MPEG4 8 × 8 motion vectors.

11 is a conceptual diagram illustrating motion vector conversion when the image in FIG. 9 has a frame structure and is a second field prediction.

12 is a conceptual diagram illustrating motion vector conversion when the image in FIG. 9 has a frame structure and is a second field prediction.

FIG. 13 is a conceptual diagram illustrating time-direction correction of a motion vector when the image in FIG. 9 has a frame structure and is a second field prediction.

FIG. 14 is a conceptual diagram illustrating a method of converting motion vector information in an MPEG2 stream into an MPEG4 motion vector of an image frame of an arbitrary magnification in the example of the motion vector conversion method according to the embodiment of the present invention.

FIG. 15 is a conceptual diagram illustrating a motion vector conversion method of a motion vector conversion method according to an embodiment of the present invention.

FIG. 16 is a block diagram illustrating an example of an image information conversion device including the motion vector conversion device according to the embodiment of the present invention.

FIG. 17 is a block diagram illustrating another example of the image information conversion device including the motion vector conversion device according to the embodiment of the present invention.

[Explanation of symbols]

160 MPEG2 decoding device, 161 MPEG2
Motion vector and macroblock mode buffer, 1
62 synthetic vector determination device, 1638 × 8 macroblock space / time correction device, 1648 × 8 motion vector re-search device, 1658 × 8 motion vector → 16 × 16 motion vector selection device, 166 16
X16 motion vector re-searching device, 167 reference macroblock address calculating device, 168 arbitrary scale image frame conversion filter, 169 MPEG4 encoding device.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Teruhiko Suzuki 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (reference) 5C059 KK41 LA07 LB05 LB11 MA00 MA05 MA23 MA31 NN01 NN21 NN28 PP05 PP06 PP07 SS02 SS08 SS11 UA02 5J064 AA02 BA01 BA16 BB03 BB13 BC11 BD02

Claims (52)

[Claims] 1. An image information conversion method, wherein a bit stream indicating MPEG2 image compression information of interlaced scanning is input, and a bit stream indicating progressive scanning MPEG4 image compression information obtained by converting an image frame size to an arbitrary magnification is output. , A 16 × 16 MPEG2 motion vector in a bit stream indicating MPEG2 image compression information to be input is input, and an 8 × 8 motion vector of MPEG4 and M
A motion vector conversion method for generating a 16 × 16 motion vector of PEG4, comprising: converting the 16 × 16 motion vector of MPEG2 into 8
A motion vector conversion method comprising generating a × 8 motion vector and a 16 × 16 MPEG4 motion vector. 2. An image information conversion method in which a bit stream indicating MPEG2 image compression information of interlaced scanning is input, and a bit stream indicating progressive scanning MPEG4 image compression information obtained by converting an image frame size to an arbitrary magnification is output. In the above, an MPEG2 16 × 16 motion vector in a bit stream indicating MPEG2 image compression information to be input is input, and an MPEG4 8 × 8 motion vector and M
A motion vector conversion method for generating a 16 × 16 motion vector of PEG4, wherein the MP generated by spatial scaling and time axis correction from the 16 × 16 motion vector of MPEG2.
When generating the above 16 × 16 motion vector of MPEG4 from the 8 × 8 motion vector of EG4, one MP
An 8 × 8 motion vector considered to have the highest encoding efficiency is selected from the 8 × 8 motion vectors of the four 8 × 8 blocks constituting the EG4 macroblock, and the selected motion vector is defined as MPEG4. A motion vector conversion method characterized by using a 16 × 16 motion vector. 3. The motion vector conversion method according to claim 1, wherein the image frame size is set at an arbitrary magnification based on the motion vector information and the macroblock information in the bit stream indicating the MPEG2 image compression information to be input. Converting, selecting an MPEG2 macroblock that overlaps a pixel range corresponding to an 8 × 8 block and a 16 × 16 macroblock of the output MPEG4 image, and representing the converted motion from the overlapping MPEG2 macroblock A motion vector conversion method comprising selecting a vector and converting the vector into an MPEG4 motion vector. 4. The motion vector conversion method according to claim 2, wherein the image frame size is set at an arbitrary magnification based on the motion vector information and the macroblock information in the bit stream indicating the MPEG2 image compression information as the input. Converting, selecting an MPEG2 macroblock that overlaps a pixel range corresponding to an 8 × 8 block and a 16 × 16 macroblock of the output MPEG4 image, and representing the converted motion from the overlapping MPEG2 macroblock A motion vector conversion method comprising selecting a vector and converting the vector into an MPEG4 motion vector. 5. The motion vector conversion method according to claim 3, wherein the image frame size is set at an arbitrary magnification based on the motion vector information and the macroblock information in the bit stream indicating the MPEG2 image compression information to be input. Converting, selecting an MPEG2 macroblock overlapping the pixel range corresponding to the 8 × 8 block and the 16 × 16 macroblock of the output MPEG4 image, and selecting the macroblock mode in the overlapping MPEG2 macroblock. However, if the motion vector is (0, 0) and a macroblock in a macroblock mode meaning that no discrete cosine transform coefficient bit is generated is included, the output MPEG4 motion vector is replaced with a zero motion vector. A motion vector conversion method characterized by: 6. The motion vector conversion method according to claim 4, wherein the image frame size is set at an arbitrary magnification based on the motion vector information and the macroblock information in the bit stream indicating the MPEG2 image compression information to be input. Converting, selecting an MPEG2 macroblock overlapping the pixel range corresponding to the 8 × 8 block and the 16 × 16 macroblock of the output MPEG4 image, and selecting the macroblock mode in the overlapping MPEG2 macroblock. However, if the motion vector is (0, 0) and a macroblock in a macroblock mode meaning that no discrete cosine transform coefficient bit is generated is included, the output MPEG4 motion vector is replaced with a zero motion vector. A motion vector conversion method characterized by: 7. The motion vector conversion method according to claim 3, wherein the image frame size is converted at an arbitrary magnification based on the motion vector information and the macroblock information in the bit stream indicating the MPEG2 image compression information as the input. Then, an MPEG2 macroblock overlapping the pixel range corresponding to the 8 × 8 block and the 16 × 16 macroblock of the output MPEG4 image is selected, and the macroblock mode is set in the overlapping MPEG2 macroblock. If a macroblock in macroblock mode, which means that no discrete cosine transform coefficient bits are generated, is included, the motion vector of the macroblock is selected and scaling corresponding to the image frame size conversion magnification is performed. Generating a motion vector of MPEG4; Vector conversion method. 8. The motion vector conversion method according to claim 4, wherein the image frame size is converted at an arbitrary magnification based on the motion vector information and the macroblock information in the bit stream indicating the MPEG2 image compression information to be input. Then, an MPEG2 macroblock overlapping the pixel range corresponding to the 8 × 8 block and the 16 × 16 macroblock of the output MPEG4 image is selected, and the macroblock mode is set in the overlapping MPEG2 macroblock. If a macroblock in macroblock mode, which means that no discrete cosine transform coefficient bits are generated, is included, the motion vector of the macroblock is selected and scaling corresponding to the image frame size conversion magnification is performed. Motion characterized by generating a motion vector of MPEG4 Vector conversion method. 9. The motion vector conversion method according to claim 3, wherein the image frame size is set at an arbitrary magnification based on the motion vector information and the macroblock information in the bit stream indicating the MPEG2 image compression information as the input. Converting, selecting an MPEG2 macroblock overlapping the pixel range corresponding to the 8 × 8 block and the 16 × 16 macroblock of the output MPEG4 image, and selecting the macroblock mode in the overlapping MPEG2 macroblock. When a macroblock in a macroblock mode meaning that the motion vector is (0, 0) is included, the output MPEG4 motion vector is set to a zero motion vector. Method. 10. The motion vector conversion method according to claim 4, wherein the image frame size is set at an arbitrary magnification based on the motion vector information and the macroblock information in the bit stream indicating the MPEG2 image compression information to be input. Converting, selecting an MPEG2 macroblock overlapping the pixel range corresponding to the 8 × 8 block and the 16 × 16 macroblock of the output MPEG4 image, and selecting the macroblock mode in the overlapping MPEG2 macroblock. When a macroblock in a macroblock mode meaning that the motion vector is (0, 0) is included, the output MPEG4 motion vector is set to a zero motion vector. Method. 11. The motion vector conversion method according to claim 3, wherein when the representative motion vector is obtained, the input M
In a bit stream indicating image compression information of PEG2, MPEG overlapping with a pixel range corresponding to an 8 × 8 block or a 16 × 16 macroblock of MPEG4
When the number of pixels (area) of the macroblock 2 is A, the number of bits allocated to each macroblock is B, and the quantization scale is Q, the parameter X is expressed as X = A / (Q · B). Using the parameter X as the representative macroblock, selecting an MPEG2 motion vector of the macroblock, and converting the selected motion vector into an MPEG4 motion vector. Method. 12. The motion vector conversion method according to claim 4, wherein when the representative motion vector is obtained, the input M
In a bit stream indicating image compression information of PEG2, MPEG overlapping with a pixel range corresponding to an 8 × 8 block or a 16 × 16 macroblock of MPEG4
When the number of pixels (area) of the macroblock 2 is A, the number of bits allocated to each macroblock is B, and the quantization scale is Q, the parameter X is expressed as X = A / (Q · B). Using the parameter X as the representative macroblock, selecting an MPEG2 motion vector of the macroblock, and converting the selected motion vector into an MPEG4 motion vector. Method. 13. The motion vector conversion method according to claim 3, wherein when the representative motion vector is obtained, the input M
In a bit stream indicating image compression information of PEG2, MPEG overlapping with a pixel range corresponding to an 8 × 8 block or a 16 × 16 macroblock of MPEG4
The number of pixels (area) A of the macroblock 2 is detected, the largest macroblock is used as the representative macroblock using the detected number of pixels (area) A, and the MPEG2 motion vector of the macroblock is calculated. Select
A motion vector conversion method characterized by converting the motion vector into an MPEG4 motion vector. 14. The motion vector conversion method according to claim 4, wherein when the representative motion vector is obtained, the input M
In a bit stream indicating image compression information of PEG2, MPEG overlapping with a pixel range corresponding to an 8 × 8 block or a 16 × 16 macroblock of MPEG4
The number of pixels (area) A of the macroblock 2 is detected, and the largest macroblock is set as the representative macroblock using the detected number of pixels (area) A, and the MPEG2 motion vector of the macroblock is calculated. Select
A motion vector conversion method characterized by converting the motion vector into an MPEG4 motion vector. 15. The motion vector conversion method according to claim 3, wherein when the representative motion vector is obtained, the input M
In a bit stream indicating image compression information of PEG2, MPEG overlapping with a pixel range corresponding to an 8 × 8 block or a 16 × 16 macroblock of MPEG4
The number of pixels (area) A of the macroblock 2 is detected, and the number of bits B assigned to each macroblock
And the detected number of pixels (area) A, calculate a parameter X as X = A / B, and use the parameter X to set the largest macroblock as the representative macroblock. A motion vector conversion method, wherein an MPEG2 motion vector of the macroblock is selected and converted to an MPEG4 motion vector. 16. The motion vector conversion method according to claim 4, wherein when the representative motion vector is obtained, the input M
In a bit stream indicating image compression information of PEG2, MPEG overlapping with a pixel range corresponding to an 8 × 8 block or a 16 × 16 macroblock of MPEG4
The number of pixels (area) A of the macroblock 2 is detected, and the number of bits B assigned to each macroblock
And the detected number of pixels (area) A, calculate a parameter X as X = A / B, and use the parameter X to set the largest macroblock as the representative macroblock. A motion vector conversion method, wherein an MPEG2 motion vector of the macroblock is selected and converted to an MPEG4 motion vector. 17. The motion vector conversion method according to claim 3, wherein when the representative motion vector is obtained, the input M
In a bit stream indicating image compression information of PEG2, MPEG overlapping with a pixel range corresponding to an 8 × 8 block or a 16 × 16 macroblock of MPEG4
2, the number of pixels (area) A of the macroblock is detected, and the quantization scale assigned to each macroblock is Q, and the detected number of pixels (area) A is used as:
A parameter X is calculated as X = A / Q. Using the parameter X, the largest macroblock is set as the representative macroblock, an MPEG2 motion vector of the macroblock is selected, and an MPEG4 motion vector is selected. A motion vector conversion method characterized by converting into a motion vector. 18. The motion vector conversion method according to claim 4, wherein when obtaining the representative motion vector, the input M
In a bit stream indicating image compression information of PEG2, MPEG overlapping with a pixel range corresponding to an 8 × 8 block or a 16 × 16 macroblock of MPEG4
2, the number of pixels (area) A of the macroblock is detected, and the quantization scale assigned to each macroblock is Q, and the detected number of pixels (area) A is used as:
A parameter X is calculated as X = A / Q. Using the parameter X, the largest macroblock is set as the representative macroblock, an MPEG2 motion vector of the macroblock is selected, and an MPEG4 motion vector is selected. A motion vector conversion method characterized by converting into a motion vector. 19. The motion vector conversion method according to claim 3, wherein when the representative motion vector is obtained, the input M
In a bit stream indicating PEG2 image compression information, the number of bits B allocated to each macroblock overlapping a pixel range corresponding to an MPEG4 8 × 8 block or a 16 × 16 macroblock is detected and quantized. Using a scale of Q and the detected number of bits B, a parameter X is calculated as X = Q · B. Using the parameter X, the least macroblock is set as the representative macroblock, A motion vector conversion method, wherein an MPEG2 motion vector of the macroblock is selected and converted to an MPEG4 motion vector. 20. The motion vector conversion method according to claim 4, wherein when the representative motion vector is obtained, the input M
In a bit stream indicating PEG2 image compression information, the number of bits B allocated to each macroblock overlapping a pixel range corresponding to an MPEG4 8 × 8 block or a 16 × 16 macroblock is detected and quantized. Using a scale of Q and the detected number of bits B, a parameter X is calculated as X = Q · B. Using the parameter X, the least macroblock is set as the representative macroblock, A motion vector conversion method, wherein an MPEG2 motion vector of the macroblock is selected and converted to an MPEG4 motion vector. 21. The motion vector conversion method according to claim 3, wherein the M is used as the input when obtaining the representative motion vector.
In the bit stream indicating the PEG2 image compression information, the number of bits B allocated to each macroblock overlapping the pixel range corresponding to the 8 × 8 block or 16 × 16 macroblock of MPEG4 is detected, and A motion vector conversion method characterized by selecting an MPEG2 motion vector of a macroblock as a representative macroblock and converting the selected macroblock into an MPEG4 motion vector. 22. The motion vector conversion method according to claim 4, wherein when the representative motion vector is obtained, the input M
In the bit stream indicating the PEG2 image compression information, the number of bits B allocated to each macroblock overlapping the pixel range corresponding to the 8 × 8 block or 16 × 16 macroblock of MPEG4 is detected, and A motion vector conversion method characterized by selecting an MPEG2 motion vector of a macroblock as a representative macroblock and converting the selected macroblock into an MPEG4 motion vector. 23. The motion vector conversion method according to claim 3, wherein when the representative motion vector is obtained, the input M
In a bit stream indicating PEG2 image compression information, a quantization scale Q assigned to each macroblock overlapping a pixel range corresponding to an 8 × 8 block or 16 × 16 macroblock of MPEG4 is detected. A motion vector conversion method, wherein the least macroblock is a representative macroblock, and an MPEG2 motion vector of the macroblock is selected and converted to an MPEG4 motion vector. 24. The motion vector conversion method according to claim 4, wherein when the representative motion vector is obtained, the input M
In a bit stream indicating PEG2 image compression information, a quantization scale Q assigned to each macroblock overlapping a pixel range corresponding to an 8 × 8 block or 16 × 16 macroblock of MPEG4 is detected. A motion vector conversion method, wherein the least macroblock is a representative macroblock, and an MPEG2 motion vector of the macroblock is selected and converted to an MPEG4 motion vector. 25. The motion vector conversion method according to claim 1, further comprising motion vector compensation, wherein the input MPEG signal is used.
Based on the motion vector information and the macroblock information in the bit stream indicating the image compression information of MPEG2, M
A PEG4 motion vector is input, and a prediction residual calculated from the input motion vector value and a zero motion vector of (0,0) are calculated, and the residual of the zero motion vector is calculated. Is given an arbitrary weight, and M
If the prediction residual of the zero motion vector weighted by the motion vector converted from the PEG2 motion vector is smaller, the MPEG4 motion vector is output as the zero motion vector, and the MPEG4 encoded stream is
A motion vector conversion method, wherein a motion vector is (0,0), and a conversion is performed such that macroblocks in a macroblock mode, which means that discrete cosine transform coefficient bits do not occur, are selected more. 26. The motion vector conversion method according to claim 2, further comprising a motion vector correction, wherein the input MPEG is used.
Based on the motion vector information and the macroblock information in the bit stream indicating the image compression information of M.2, M is converted from the motion vector of MPEG2 by the motion vector conversion.
A PEG4 motion vector is input, and a prediction residual calculated from the input motion vector value and a zero motion vector of (0,0) are calculated, and the residual of the zero motion vector is calculated. Is given an arbitrary weight, and M
If the prediction residual of the zero motion vector weighted by the motion vector converted from the PEG2 motion vector is smaller, the MPEG4 motion vector is output as the zero motion vector, and the MPEG4 encoded stream is
A motion vector conversion method, wherein a motion vector is (0,0), and a conversion is performed such that macroblocks in a macroblock mode, which means that discrete cosine transform coefficient bits do not occur, are selected more. 27. An image information conversion apparatus which receives a bit stream indicating MPEG2 image compression information of interlaced scanning as input and outputs a bit stream indicating progressive scanning MPEG4 image compression information obtained by converting an image frame size to an arbitrary magnification. In the motion vector conversion device of the above, a 16 × 16 MPEG2 motion vector in a bit stream indicating MPEG2 image compression information to be input is input, and an 8 × 8 motion vector of MPEG4 and M
A motion vector conversion device for generating a 16 × 16 motion vector of PEG4, comprising spatial scaling and time axis correction means, and converting the 16 × 16 motion vector of MPEG2 by the spatial scaling and time axis correction means. , M above
A motion vector conversion apparatus for generating an 8 × 8 motion vector of PEG4 and a 16 × 16 motion vector of MPEG4. 28. An image information conversion apparatus which receives a bit stream indicating MPEG2 image compression information of interlaced scanning as input and outputs a bit stream indicating progressive scanning MPEG4 image compression information obtained by converting an image frame size to an arbitrary magnification. In the above, an MPEG2 16 × 16 motion vector in a bit stream indicating input MPEG2 image compression information is input, and an MPEG4 8 × 8 motion vector and M
A motion vector converter for generating a 16 × 16 motion vector of PEG4, comprising spatial scaling and time axis correction means, and four 8 bits constituting one MPEG4 macroblock
Selecting means for selecting an 8 × 8 motion vector which is considered to have the highest encoding efficiency from the 8 × 8 motion vectors of the × 8 block, and from the 16 × 16 motion vector of MPEG2, By means of spatial scaling and time axis correction means, the above M
When generating an 8 × 8 motion vector of PEG4 and a 16 × 16 motion vector of MPEG4, the 8 × 8 motion vector selected by the selection means and considered to have the highest encoding efficiency is converted to an MPEG4 motion vector. A motion vector conversion device, wherein the motion vector is a 16 × 16 motion vector. 29. The motion vector conversion apparatus according to claim 27, wherein the image frame size is set at an arbitrary magnification based on the motion vector information and the macroblock information in the bit stream indicating the MPEG2 image compression information as the input. Image frame size converting means for converting; selecting means for selecting an MPEG2 macroblock overlapping a pixel range corresponding to an 8 × 8 block and a 16 × 16 macroblock of the output MPEG4 image; A motion vector conversion unit for selecting a representative motion vector to be converted from an MPEG2 macroblock and converting the selected motion vector into an MPEG4 motion vector. 30. The motion vector conversion apparatus according to claim 28, wherein the image frame size is set at an arbitrary magnification based on the motion vector information and the macroblock information in the bit stream indicating the MPEG2 image compression information to be input. Image frame size converting means for converting; selecting means for selecting an MPEG2 macroblock overlapping a pixel range corresponding to an 8 × 8 block and a 16 × 16 macroblock of the output MPEG4 image; A motion vector conversion unit for selecting a representative motion vector to be converted from an MPEG2 macroblock and converting the selected motion vector into an MPEG4 motion vector. 31. The motion vector conversion apparatus according to claim 29, wherein the image frame size is set at an arbitrary magnification based on the motion vector information and the macroblock information in the bit stream indicating the MPEG2 image compression information to be input. Image frame size converting means for converting; and selecting means for selecting an MPEG2 macroblock overlapping a pixel range corresponding to an 8 × 8 block and a 16 × 16 macroblock of the output MPEG4 image, When the overlapping MPEG2 macroblock includes a macroblock in a macroblock mode in which the motion vector is (0, 0) and a discrete cosine transform coefficient bit is not generated, The output MPEG4 motion vector may be a zero motion vector. Motion vector conversion unit. 32. The motion vector conversion device according to claim 30, wherein the image frame size is set at an arbitrary magnification based on the motion vector information and the macroblock information in the bit stream indicating the MPEG2 image compression information as the input. Image frame size converting means for converting; and selecting means for selecting an MPEG2 macroblock overlapping a pixel range corresponding to an 8 × 8 block and a 16 × 16 macroblock of the output MPEG4 image, When the overlapping MPEG2 macroblock includes a macroblock in a macroblock mode in which the motion vector is (0, 0) and a discrete cosine transform coefficient bit is not generated, The output MPEG4 motion vector may be a zero motion vector. Motion vector conversion unit. 33. The motion vector conversion apparatus according to claim 29, wherein the image frame size is converted at an arbitrary magnification based on the motion vector information and the macroblock information in the bit stream indicating the MPEG2 image compression information to be input. Image frame size converting means, and selecting means for selecting an MPEG2 macroblock overlapping a pixel range corresponding to an 8 × 8 block and a 16 × 16 macroblock of the output MPEG4 image, When the overlapping MPEG2 macroblock includes a macroblock whose macroblock mode is a macroblock mode meaning that no discrete cosine transform coefficient bits are generated, the motion vector of the macroblock is selected and the image frame is selected. By performing scaling corresponding to the size conversion magnification, the MPEG Motion vector conversion unit and generating a motion vector. 34. The motion vector conversion device according to claim 30, wherein the image frame size is converted at an arbitrary magnification based on the motion vector information and the macroblock information in the bit stream indicating the MPEG2 image compression information to be input. Image frame size converting means, and selecting means for selecting an MPEG2 macroblock overlapping a pixel range corresponding to an 8 × 8 block and a 16 × 16 macroblock of the output MPEG4 image, When the overlapping MPEG2 macroblock includes a macroblock whose macroblock mode is a macroblock mode meaning that no discrete cosine transform coefficient bit is generated, a motion vector of the macroblock is selected, By performing scaling corresponding to the size conversion magnification, the above MPEG4 A motion vector conversion device for generating a motion vector. 35. The motion vector conversion apparatus according to claim 29, wherein the image frame size is set at an arbitrary magnification based on the motion vector information and the macroblock information in the bit stream indicating the MPEG2 image compression information as the input. Image frame size converting means for converting; and selecting means for selecting an MPEG2 macroblock overlapping a pixel range corresponding to an 8 × 8 block and a 16 × 16 macroblock of the output MPEG4 image, If the overlapping MPEG2 macroblock includes a macroblock whose macroblock mode is the macroblock mode meaning that the motion vector is (0,0), the output MPEG4 motion vector is set to zero. A motion vector conversion device characterized in that the motion vector is a motion vector. 36. The motion vector conversion apparatus according to claim 30, wherein the image frame size is set at an arbitrary magnification based on the motion vector information and the macroblock information in the bit stream indicating the MPEG2 image compression information to be input. Image frame size converting means for converting; and selecting means for selecting an MPEG2 macroblock overlapping a pixel range corresponding to an 8 × 8 block and a 16 × 16 macroblock of the output MPEG4 image, When the macroblock mode included in the overlapping MPEG2 macroblocks includes a macroblock in the macroblock mode meaning that the motion vector is (0,0), the output MPEG4 motion vector is set to zero. A motion vector conversion device for converting a motion vector. 37. The motion vector conversion device according to claim 29, wherein the M is used as the input when the representative motion vector is obtained.
In a bit stream indicating image compression information of PEG2, MPEG overlapping with a pixel range corresponding to an 8 × 8 block or a 16 × 16 macroblock of MPEG4
When the number of pixels (area) of the macroblock 2 is A, the number of bits allocated to each macroblock is B, and the quantization scale is Q, the parameter X is expressed as X = A / (Q · B). Using a parameter X calculated by the calculating means,
A motion vector conversion apparatus, wherein the largest macroblock is the representative macroblock, an MPEG2 motion vector of the macroblock is selected, and the selected macroblock is converted into an MPEG4 motion vector. 38. The motion vector conversion apparatus according to claim 30, wherein the M is used as the input when the representative motion vector is obtained.
In a bit stream indicating image compression information of PEG2, MPEG overlapping with a pixel range corresponding to an 8 × 8 block or a 16 × 16 macroblock of MPEG4
When the number of pixels (area) of the macroblock 2 is A, the number of bits allocated to each macroblock is B, and the quantization scale is Q, the parameter X is expressed as X = A / (Q · B). Using a parameter X calculated by the calculating means,
A motion vector conversion apparatus, wherein the largest macroblock is the representative macroblock, an MPEG2 motion vector of the macroblock is selected, and the selected macroblock is converted into an MPEG4 motion vector. 39. The motion vector conversion device according to claim 29, wherein the M is used as the input when obtaining the representative motion vector.
In a bit stream indicating image compression information of PEG2, MPEG overlapping with a pixel range corresponding to an 8 × 8 block or a 16 × 16 macroblock of MPEG4
And a detecting means for detecting the number of pixels (area) A of the two macroblocks. Using the number of pixels (area) A detected by the detecting means, the largest macroblock is set as the representative macroblock. A motion vector conversion apparatus for selecting an MPEG2 motion vector of a macroblock and converting the selected motion vector into an MPEG4 motion vector. 40. The motion vector conversion device according to claim 30, wherein the M is used as the input when the representative motion vector is obtained.
In a bit stream indicating image compression information of PEG2, MPEG overlapping with a pixel range corresponding to an 8 × 8 block or a 16 × 16 macroblock of MPEG4
And a detecting means for detecting the number of pixels (area) A of the two macroblocks. Using the number of pixels (area) A detected by the detecting means, the largest macroblock is set as the representative macroblock. A motion vector conversion apparatus for selecting an MPEG2 motion vector of a macroblock and converting the selected motion vector into an MPEG4 motion vector. 41. The motion vector conversion device according to claim 29, wherein the M is used as the input when obtaining the representative motion vector.
In a bit stream indicating image compression information of PEG2, MPEG overlapping with a pixel range corresponding to an 8 × 8 block or a 16 × 16 macroblock of MPEG4
Detecting means for detecting the number of pixels (area) A of two macro blocks, and the number of bits B assigned to each macro block
And the number of pixels (area) A detected by the detection means
And a calculating means for calculating the parameter X as X = A / B using the parameter X, and using the parameter X calculated by the calculating means,
A motion vector conversion apparatus characterized in that the largest macroblock is the representative macroblock, and an MPEG2 motion vector of the macroblock is selected and converted to an MPEG4 motion vector. 42. The motion vector conversion device according to claim 30, wherein the M is used as the input when the representative motion vector is obtained.
In a bit stream indicating image compression information of PEG2, MPEG overlapping with a pixel range corresponding to an 8 × 8 block or a 16 × 16 macroblock of MPEG4
Detecting means for detecting the number of pixels (area) A of two macro blocks, and the number of bits B assigned to each macro block
And the number of pixels (area) A detected by the detection means
And calculating means for calculating the parameter X as X = A / B by using the parameter X, and using the parameter X calculated by the calculating means
A motion vector conversion apparatus characterized in that the largest macroblock is the representative macroblock, and an MPEG2 motion vector of the macroblock is selected and converted to an MPEG4 motion vector. 43. The motion vector conversion apparatus according to claim 29, wherein the M is used as the input when obtaining the representative motion vector.
In a bit stream indicating image compression information of PEG2, MPEG overlapping with a pixel range corresponding to an 8 × 8 block or a 16 × 16 macroblock of MPEG4
A detecting means for detecting the number of pixels (area) A of the two macroblocks; a quantization scale Q assigned to each macroblock; and the number of pixels (area) A detected by the detecting means. Calculating means for calculating the parameter X as X = A / Q, and using the parameter X calculated by the calculating means,
A motion vector conversion apparatus characterized in that the largest macroblock is the representative macroblock, and an MPEG2 motion vector of the macroblock is selected and converted to an MPEG4 motion vector. 44. The motion vector conversion device according to claim 30, wherein the input M is used when obtaining the representative motion vector.
In a bit stream indicating image compression information of PEG2, MPEG overlapping with a pixel range corresponding to an 8 × 8 block or a 16 × 16 macroblock of MPEG4
A detecting means for detecting the number of pixels (area) A of the two macroblocks; a quantization scale Q assigned to each macroblock; and the number of pixels (area) A detected by the detecting means. Calculating means for calculating the parameter X as X = A / Q, and using the parameter X calculated by the calculating means,
A motion vector conversion apparatus characterized in that the largest macroblock is the representative macroblock, and an MPEG2 motion vector of the macroblock is selected and converted to an MPEG4 motion vector. 45. The motion vector conversion apparatus according to claim 29, wherein the M is used as the input when the representative motion vector is obtained.
Detecting means for detecting a bit number B allocated to each macroblock overlapping a pixel range corresponding to an MPEG4 8 × 8 block or a 16 × 16 macroblock in a bit stream indicating PEG2 image compression information; And calculating means for calculating the parameter X as X = Q · B using the number of bits B detected by the detecting means and the quantization scale Q. Using the parameter X,
A motion vector conversion apparatus characterized in that the least macroblock is the representative macroblock, an MPEG2 motion vector of the macroblock is selected, and the selected macroblock is converted into an MPEG4 motion vector. 46. The motion vector conversion device according to claim 30, wherein the M is used as the input when obtaining the representative motion vector.
Detecting means for detecting a bit number B allocated to each macroblock overlapping a pixel range corresponding to an MPEG4 8 × 8 block or a 16 × 16 macroblock in a bit stream indicating PEG2 image compression information; And calculating means for calculating the parameter X as X = Q · B using the number of bits B detected by the detecting means and the quantization scale Q. Using the parameter X,
A motion vector conversion apparatus characterized in that the least macroblock is the representative macroblock, an MPEG2 motion vector of the macroblock is selected, and the selected macroblock is converted into an MPEG4 motion vector. 47. The motion vector conversion device according to claim 29, wherein the M is used as the input when obtaining the representative motion vector.
In a bit stream indicating PEG2 image compression information, a detecting means for detecting the number of bits B allocated to each macroblock overlapping a pixel range corresponding to an 8 × 8 block or a 16 × 16 macroblock of MPEG4 A motion vector conversion apparatus comprising: selecting an MPEG2 motion vector of the macroblock as a representative macroblock, and converting the selected macroblock into an MPEG4 motion vector. 48. The motion vector conversion device according to claim 30, wherein the M is used as the input when obtaining the representative motion vector.
In a bit stream indicating PEG2 image compression information, a detecting means for detecting the number of bits B allocated to each macroblock overlapping a pixel range corresponding to an 8 × 8 block or a 16 × 16 macroblock of MPEG4 A motion vector conversion apparatus comprising: selecting an MPEG2 motion vector of the macroblock as a representative macroblock, and converting the selected macroblock into an MPEG4 motion vector. 49. The motion vector conversion device according to claim 29, wherein the M is used as the input when obtaining the representative motion vector.
Detecting means for detecting a quantization scale Q assigned to each macroblock overlapping a pixel range corresponding to an MPEG4 8 × 8 block or a 16 × 16 macroblock in a bit stream indicating PEG2 image compression information. A motion vector conversion apparatus, wherein the least macroblock is set as a representative macroblock, and an MPEG2 motion vector of the macroblock is selected and converted to an MPEG4 motion vector. 50. The motion vector conversion device according to claim 30, wherein the input is M when obtaining the representative motion vector.
Detecting means for detecting a quantization scale Q assigned to each macroblock overlapping a pixel range corresponding to an MPEG4 8 × 8 block or a 16 × 16 macroblock in a bit stream indicating PEG2 image compression information. A motion vector conversion apparatus, wherein the least macroblock is set as a representative macroblock, and an MPEG2 motion vector of the macroblock is selected and converted to an MPEG4 motion vector. 51. The motion vector converting apparatus according to claim 27, further comprising a motion vector compensating means, based on motion vector information and macro block information in a bit stream indicating MPEG2 image compression information to be input. The motion vector of MPEG4 converted from the motion vector of MPEG2 by the motion vector conversion is input, and the prediction residual obtained by the input motion vector value and the prediction residual obtained by the zero motion vector of (0,0). Prediction means for calculating a difference, performing arbitrary weighting on the residual of the zero motion vector calculated by the calculation means, and weighting the motion vector converted from the motion vector of MPEG2. If the residual is smaller, use the MPEG4 motion vector as the zero motion vector Output, MPE
The motion vector is (0,0) in the G4 encoded stream.
A motion vector conversion apparatus that performs conversion so that macroblocks in a macroblock mode, which means that discrete cosine transform coefficient bits do not occur, are selected more. 52. The motion vector converting apparatus according to claim 28, further comprising a motion vector compensating means, based on motion vector information and macroblock information in a bit stream indicating MPEG2 image compression information to be input. The motion vector of MPEG4 converted from the motion vector of MPEG2 by the motion vector conversion is input, and the prediction residual obtained by the input motion vector value and the prediction residual obtained by the zero motion vector of (0,0). Prediction means for calculating a difference, arbitrarily weighting the residual of the zero motion vector calculated by the calculation means, and weighting the motion vector converted from the MPEG2 motion vector. If the residual is smaller, use the MPEG4 motion vector as the zero motion vector Output, MPE
The motion vector is (0,0) in the G4 encoded stream.
A motion vector conversion apparatus that performs conversion so that macroblocks in a macroblock mode, which means that no discrete cosine transform coefficient bits are generated, are selected more.