JPH09182032A - Video signal processing device - Google Patents

Abstract

(57) Abstract: A video signal that has been subjected to motion compensation type signal processing such as MPEG2 can be displayed in high image quality without causing image quality deterioration due to interlace interference, and still images and moving images can be displayed. Achieve high quality images with less difference in image quality without discomfort at low cost. A motion-compensated image for inputting a video signal that has been subjected to motion-compensated image compression using a motion vector indicating a direction in which the image has moved between frames or fields, and decoding and outputting the video signal. Compression / decoding means and motion-compensation-type scanning conversion means for inputting the interlaced scanning video signal output from the motion compensation type image compression / decoding means, converting to a progressive scanning video signal, and outputting the video signal. Motion vector supply means for extracting a motion vector included in the video signal subjected to the motion compensation type image compression and supplying the motion vector to the motion compensation type scanning conversion means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal processing device, and more particularly to a video signal which has been subjected to motion compensation type image compression using a motion vector and is decoded into an interlaced scanning video signal, and then motion compensation. TECHNICAL FIELD The present invention relates to a video signal processing apparatus for performing a scan conversion of a mold to convert it into a video signal of progressive scanning.

[0002]

2. Description of the Related Art In recent years, digital compression technology and digital transmission technology for images have been put to practical use in fields such as broadcasting. For example, the MPEG2 system, which has been internationally standardized, can be realized at a bit rate lower by one digit or more in order to obtain an image quality equal to or higher than that of the current TV system. By utilizing this narrow band, it is possible to perform simultaneous multi-channel transmission and to realize a longer recording time than in the conventional case within the same transmission band. Therefore,
Not only transmitting video information as in current broadcasting,
Simultaneous transmission of image / text information such as program guides is also possible. Further, there is a feature that it is possible to suppress the S / N deterioration due to transmission distortion and the like, which is a problem peculiar to the conventional analog transmission, and to easily improve the image quality.

Digital broadcasting that has already started or is being planned using the MPEG2 system can be received by adding an adapter to the existing TV receiver. Therefore, the output signal from this adapter is the same interlaced scanning signal as in the current TV system so that the current TV receiver can accept it.

For example, FIG. 5 shows “Nikkei Byte”, September 1995.
It is a block diagram of a receiver for digital broadcasting which is scheduled to be broadcast from 1996 using a communication satellite as shown on page 145 of the monthly issue. In FIG. 5, 1 is a signal input terminal, 2 is a digital broadcasting tuner, 3 is a descrambler, 4 is an MPEG2 demultiplexer, and 5 is MPEG.
2 video decoder, 6 video encoder, 7 MPEG
2 is an audio decoder, 8 is a video output terminal, and 9 is an audio output terminal.

The digital broadcast tuner 2 inputs a signal from an antenna, demodulates and outputs the signal, and the descrambler 3 decrypts the signal when the broadcast is a pay broadcast. The MPEG2 demultiplexer 4 divides the input signal into MPEG2 video data and audio data, and the video data is MPEG2 video decoder 5
Then, the audio data is output to the MPEG2 audio decoder 7. The MPEG2 video decoder 5 uses the MPEG2
Image decoding processing is performed to output the same interlaced scanning video signal as the current TV signal, and the video encoder 6 converts the input signal into a video signal and outputs the video signal from the video output terminal 8. The MPEG2 audio decoder 7 performs an MPEG2 audio decoding process and outputs an audio signal from an audio output terminal 9. The output terminals 8 and 9 are connected to the TV receiver.

[0006]

It is well known that in display by interlaced scanning, fine horizontal stripes or image disturbance such as line flicker occurs near the vertical edges of the image and the image quality deteriorates. In digital broadcasting, which is the new service described above, it is planned to use character information such as program guides more than in current broadcasting. When the same interlaced scanning display as in the current TV system is performed, the above image quality deterioration is an important problem. Become.

This interlace interference can be removed by scanning conversion of an interlaced scanning video signal into a progressive scanning video signal for display. Then, according to the motion of the image, a TV reception that performs motion-adaptive interlace / sequential conversion scanning, in which a signal of a preceding and following field is used for a still image and a signal of the same field is used for a moving image, that is, a signal of an interpolating scan line is created. The machine is also commercialized.

By the way, in the above motion adaptive processing, interlace interference can be completely removed for a still image and a remarkable image quality improving effect can be obtained, but for a moving image, an image quality improving effect can be obtained. Can hardly get. Therefore, there is a new problem that an extreme difference in image quality occurs between a still image and a moving image, resulting in an unnatural image.

That is, when the MPEG2 signal is decoded by the adapter and displayed by the conventional TV receiver, there is a problem that the image quality is deteriorated due to the interlace interference, and the improvement is made by the motion adaptive scanning conversion. However, there is a problem that a moving image has no improvement effect and an unnatural image is generated due to a difference in image quality between a still image and a moving image.

Therefore, the technical problem to be solved by the present invention is to solve the above-mentioned problems of the prior art. The purpose thereof is to display the character information of the MPEG2 signal, etc. An object of the present invention is to provide at a low cost a high-performance video signal processing device that does not cause image quality deterioration due to interlace interference and has a small difference in image quality between a still image and a moving image.

[0011]

In order to achieve the above object, a video signal processing apparatus according to the present invention is a motion compensation type using a motion vector indicating in which direction an image moves between frames or fields. A motion-compensated image compression / decoding means for inputting a video signal subjected to image compression, decoding and outputting the same, and an interlaced scanning video signal output from the motion-compensated image compression / decoding means are input and sequentially. Motion-compensated scan conversion means using a motion vector for converting to a scan video signal and outputting the motion vector included in the motion-compensated image compressed video signal to perform the motion-compensated scan And a motion vector supply means for supplying to the conversion means.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the drawings. FIG. 1 shows an example of one embodiment of the present invention (hereinafter,
It is a block diagram of a video signal processing device according to this example). In the figure, 1 is a signal input terminal, 2 is a digital broadcasting tuner, 3 is a descrambler, 4 is an MPEG2 demultiplexer, 5 is an MPEG2 video decoder, and 7 is an MP.
EG2 audio decoder, 8 video output terminal, 9 audio output terminal, 10 motion vector decoder, 11 motion compensation type scanning conversion means, 12 signal input terminal, 13 switch, 14 motion vector control means , 15 are video output terminals.

The digital broadcasting tuner 2 inputs a signal from the antenna via the signal input terminal 1, demodulates it, and outputs it. The descrambler 3 decrypts the signal when the broadcast is a pay broadcast. MPEG
The 2 demultiplexer 4 divides the input signal into MPEG2 video data and audio data, the video data to the MPEG2 video decoder 5, and the audio data to MPEG2.
It outputs to the audio decoder 7, respectively. The MPEG2 audio decoder 7 performs an MPEG2 audio decoding process and outputs an audio signal from an audio output terminal 9.

The MPEG2 video decoder 5 is an MPEG2
Then, the video signal of the same interlaced scanning as the current TV signal is output to the switch 13 and the video output terminal 15. The switch 13 has a signal input terminal 1
The output signal of the current TV decoder input from 2 and MPE
The output signal of the G2 video decoder 5 is selectively output according to the input switching signal. Here, examples of current TV decoders include NTSC and EDTV2 decoders. These decoders are built in the current TV receiver and are well known, so the description thereof is omitted here. The scanning conversion means 11 inputs an interlaced scanning video signal, creates a motion compensation type interpolating scanning line using a motion vector, and converts it into a progressive scanning video signal.
Output from the video output terminal 8.

Also, the motion vector decoder 10 uses the MPE
The motion vector signal included in the MPEG2 video data from the G2 demultiplexer 4 is decoded, and the scan conversion unit 1
Feed to 1. At this time, the motion vector is controlled by the motion vector control means 14 so as to be valid when the output signal of the MPEG2 video decoder 5 is selected by the switch 13.

The creation of the above-described motion compensation type interpolation scanning line will be described with reference to FIGS. FIG. 2 is a block diagram showing details of the motion compensation type scan conversion means 11. Further, FIG. 3 is a schematic diagram of motion-adaptive scanning line interpolation, in which the horizontal axis represents time, the vertical axis represents the vertical direction of the TV screen, and the scanning lines and the interpolation scanning lines are indicated by ∘ and Δ marks, respectively. . Further, FIG. 4 is a schematic diagram of motion compensation type scanning line interpolation when there is a motion vector.

In FIG. 2, 21 is an input terminal for a video signal, 22 is an input terminal for a motion vector, 23 is an intra-field interpolating circuit for a moving image, 24 and 25 are field memories,
26 is a delay circuit for timing adjustment, 27 is a motion detection circuit, 28 is a mixing circuit, 29 and 30 are time compression circuits, 31
Is a switching circuit, and 32 is an output terminal.

The interlaced scanning video signal input from the input terminal 21 is supplied to the intra-field interpolation circuit 23, the field memory 24 and the like. The intra-field interpolation circuit 23 calculates an average of, for example, upper and lower scanning lines in the same field as the interpolation scanning line to be created, and outputs it as an interpolating scanning line signal of the moving image in FIG. The field memory 24 outputs a video signal of one field past and uses this as an interpolation scanning line signal of the still image in FIG.

The motion detection circuit 27 inputs the input signal from the input terminal 21 and the output signal from the field memory 25, and based on the difference between them, that is, the presence or absence of the difference between the signals separated by one frame. , Detect image movement. The mixing circuit 28 receives the moving image signal from the intra-field interpolating circuit 23 and the still image signal from the field memory 24, changes the mixing ratio of both signals according to the motion signal from the motion detecting circuit 27, and outputs the signal. To do.

The time compression circuits 29 and 30 respectively receive the interpolated scanning line signal from the mixing circuit 28 and the actual scanning line signal from the input terminal 21, compress the time axis in half, and use the switching circuit 31 in the subsequent stage. , The actual scanning line signal and the interpolating scanning line signal are switchably output for each scanning period after the time compression. In this way, the switching circuit 31 outputs a progressive scanning video signal.

On the other hand, a motion vector is input from the input terminal 22 and supplied to the field memory 24. In the field memory 24, the timing of reading from the memory is controlled by this motion vector. When the image moves in a certain direction as shown in FIG. 4A, for example, when “vertical vector = 2” as shown in FIG. 4B, a signal of one field past output from the field memory 24 is output. Are controlled to be read after being delayed by one horizontal scanning period of interlaced scanning.

As described above, in this example, by performing progressive scanning display, digital broadcasting can be displayed with high image quality without line flicker, and when an image moves in a fixed direction, scan conversion using a motion vector is performed. As a result, the deterioration of the image quality of the moving image can be reduced. Further, since the motion vector originally transmitted for digital broadcast decoding is used, it is possible to eliminate the need for the motion vector itself to be detected by the receiver and realize a large circuit reduction.

In the above example, the motion vector decoder 10 is provided to decode the motion vector included in the MPEG2 video data in order to obtain the motion vector, but the present invention is not limited to this. is not. That is, since a motion vector is naturally used in the MPEG2 video decoding processing in the MPEG2 video decoder 5, the motion vector may be output for the scan conversion means 11. In this case, it is not necessary to separately provide a motion vector decoding unit, and it is sufficient to match the timing and the like so that the video decoding motion vector can be used as the scan conversion motion vector, which is advantageous in that the circuit can be reduced.

In the above description, digital broadcasting using MPEG2 was taken as an example of the signal subjected to the motion compensation type image compression, but the present invention is not limited to this. For example, MPEG1 or MPEG2
Even when the reproduction signal from the package medium recorded by performing the compression is processed, the same effect can be obtained. Alternatively, the same effect can be obtained even in the case of processing a video signal of a TV phone that is transmitted after being compressed by H261.

[0025]

As described above, according to the present invention, MPEG
Video signals that have undergone motion compensation type signal processing such as 2 can be displayed in high image quality without causing image quality deterioration due to interlace interference, and there is little discomfort from still images to moving images. High quality images can be realized at low cost.

[Brief description of the drawings]

FIG. 1 is a block diagram of a video signal processing device according to an embodiment of the present invention.

FIG. 2 is a block diagram of scan conversion means in FIG.

FIG. 3 is a schematic diagram of motion adaptive scanning line interpolation.

FIG. 4 is a schematic diagram of motion-compensated scanning line interpolation when there is a motion vector.

FIG. 5 is a block diagram of a conventional video signal processing device.

[Explanation of symbols]

 2 Digital Broadcast Tuner 3 Descrambler 4 MPEG2 Demultiplexer 5 MPEG2 Video Decoder 7 MPEG2 Audio Decoder 10 Motion Vector Decoder 11 Motion Compensation Scan Converter 13 Switch 14 Motion Vector Control Means 23 In-Field Interpolator 24, 25 Field Memory 26 Delay Circuit 27 Motion detection circuit 28 Mixing circuit 29, 30 Time compression circuit 31 Switching circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kentaro Teranishi Kentaro Teranishi, 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa, Ltd. Hitachi, Ltd., Multimedia Systems Development Headquarters (72) Hirohiro Hirano 1-280, Higashi Koikeku, Kokubunji, Tokyo Address Central Research Laboratory, Hitachi, Ltd. (72) Inventor Yasuhiro Kasahara 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa, Ltd.

Claims (1)

[Claims] 1. A video signal processing for inputting, decoding and outputting a video signal that has been subjected to motion compensation type image compression using a motion vector indicating in which direction an image has moved between frames or fields. The apparatus has a scan conversion means for inputting an interlaced scanning video signal outputted from the motion compensation type image compression decoding means, converting it to a progressive scanning video signal and outputting the same, wherein the scanning conversion means is a motion vector. A video signal processing device, which is a motion-compensating scan conversion means to be used, wherein a motion vector for motion-compensating image compression / decoding is used as a motion vector to be used.