JP2000270243A - Image pickup recording device with display monitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the difference between an image to be used for image display at the time of photographing and an image to be recorded by providing a noise generating means for generating an image noise corresponding to compressibility and a noise adding means for adding an image noise to a monitor signal. SOLUTION: This device has a noise generating means for generating an image noise corresponding to compressibility and a noise adding means for adding an image noise to a monitor signal. By intentionally adding noise to a compressed image and an image to be observed at the time of photographing, what makes a photographer conscious of noise by compressibility or what is equivalent to a compressed image is displayed to allow the person to easily decide the compressibility of the image. For example, this device consists of an image input part 101, an image processing part 102, a main memory 103, a digital signal processor 104 for performing the compression with software, a noise quantity controller 105, a noise adding circuit 106 and an image display part 107.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for displaying image data when compressing and storing image data.

[0002]

2. Description of the Related Art Conventionally, an image before compression is displayed as it is on an image display, which is different from a compressed image.

For this reason, an image observed by a photographer at the time of photographing and an image captured and observed by a computer or the like are considerably different when the compression ratio is high.

In the case where the image compression portion is implemented by hardware, the compression ratio can be confirmed by displaying the compressed and restored image. However, when the compression is performed by software processing, Is not performed because it takes too much time to check the image.

[0005] In addition, since the display device itself is smaller than the actual image size, block noise and the like cannot be seen as far as the display is viewed, but the noise is noticeable when reproduced on a computer.

[0006]

When a photographed image is different from an image displayed on a liquid crystal screen at the time of photographing, it is not easy for a photographer to select a compression ratio by himself.

If an incorrect selection is made, a necessary image cannot be obtained, and a re-taking has to be performed.

An object of the present invention is to solve the above-mentioned conventional problems, and proposes a method for eliminating a difference between an image used for displaying an image at the time of photographing and an image to be recorded.

[0009]

According to the first aspect of the present invention, there is provided an image capturing and recording apparatus with a display monitor for performing compression recording, wherein: a noise generating means for generating image noise corresponding to a compression ratio; And noise adding means for adding

According to the second aspect of the present invention, in the configuration of the first aspect, the noise generating means is a block noise generating means for generating block noise corresponding to the compression ratio.

According to the third aspect of the present invention, an image recording apparatus with a display monitor for compressing and recording a captured moving image by MPEG and displaying an image used for motion prediction on an image monitor.

According to a fourth aspect of the present invention, in the image pickup recording apparatus with a display monitor for performing compression recording, display selection of a compressed image and an image before compression is performed.

According to a fifth aspect of the present invention, in the imaging and recording apparatus with a display monitor for performing compression recording, when the monitor size is reduced, the noise addition amount is increased.

[0014]

FIG. 1 is a diagram illustrating the principle of image processing according to the present invention.

Reference numeral 101 denotes an image input unit; 102, an image processing unit; and 103, a main memory. Numeral 104 denotes a digital signal processor (hereinafter abbreviated as DSP) for compressing in a software manner, 105 denotes a noise amount control, 106 denotes a noise adding circuit, and 107 denotes an image display unit.

The noise may be of any type.
It seems to be effective to add 8x8 block noise that occurs during PEG compression.

If the noise is not conspicuous due to the small size of the display device, the block noise corresponding to the size of the display image is not added with the block noise corresponding to the actually acquired image size. By putting on, it is possible to make the photographer more conscious of block noise.

Further, the magnitude of the noise is changed in accordance with the compression ratio.

FIG. 2 is a block diagram when MPEG moving images are compressed.

201 is an image input device, 202 is an image display device, 203 is a frame memory, 204 is DCT conversion,
205 is quantization, 206 is inverse quantization, 207 is IDCT
Transformation, 208 is a loop filter, 209 is a prediction memory,
210 is motion vector detection, 211 is coding parameter control, 212 is variable length coding, 213 is multiplexing, 214
Represents a code buffer.

Normally, a frame memory is directly output for displaying an image. However, in the case of an MPEG moving image, a predicted image for performing motion prediction for creating a next image is stored in the memory. Since this image is equivalent to the compressed image, the difference between the displayed image and the compressed image can be eliminated by using this image for display as shown by the dotted line.

According to the present invention, a device which intentionally puts noise on a compressed image and an image to be observed at the time of photographing to make the photographer aware of the noise due to the compression ratio, or an image equivalent to a compressed image is displayed so that the photographer can easily perform the process. The compression ratio of the image can be determined in advance.

Various circuits for adding a noise component are conceivable. For example, a circuit as shown in FIG.

Reference numeral 401 denotes a noise adding circuit; 402, an input buffer; 403, a matrix of an original image 8 × 8; 404, 8 × 8, the average luminance calculation; , 407 is its inverse quantization, 408 is a weighting control determined by the quantization result, 409 is an 8 × 8 matrix of high frequency components, and 410 is a low frequency component (8 × 8
Pixel average), 411 is its inverse quantization, 412
Represents an output buffer.

403 and 409 are memories or
It consists of a register.

In JPEG compression, a block noise component becomes a problem. Therefore, in FIG. 3, the low frequency component obtained by calculating the 8 × 8 block average and the high frequency component obtained by subtracting the low frequency component from the 8 × 8 original image are separated, the respective powers are obtained, and the powers are quantized.

Next, they are inversely quantized, and the ratio between the quantized / inversely quantized value and the power before quantization is multiplied by each frequency component and added.

The noise amount of a block can be set by a quantization value of power. If the quantization value is large, the block between 8 × 8 blocks becomes discontinuous, and block noise is formed.

FIG. 4 shows an embodiment in an MPEG moving picture camera.

Reference numeral 501 denotes an image input unit; and 502, a main memory, which includes a frame memory and a motion prediction memory. A DSP 503 compresses a moving image. The DSP uses the main memory as a buffer when performing motion prediction.

A display selection device 504 can select a frame memory and a predicted image (compressed image) according to the photographer's intention. 505 is a display device. The motion prediction memory corresponds to 209 shown in FIG.

[0032]

According to the present invention, the photographer can know that the image is degraded when the compression ratio is high at the time of photographing, so that the compression ratio can be selected on the spot. .

According to the first aspect of the present invention, the photographer is provided with a noise generating means for generating image noise corresponding to the compression ratio and a noise adding means for adding the image noise to a monitor signal, so that the photographer can take a picture at the time of photographing. When the compression ratio is high, it is possible to know that the image is degraded.

According to a second aspect of the present invention, in the configuration of the first aspect, the noise generating means is a block noise generating means for generating a block noise corresponding to the compression rate, so that the block is generated in accordance with the high compression rate. It can be confirmed that the noise increases.

According to a third aspect of the present invention, in an image capturing and recording apparatus with a display monitor for compressing and recording a captured moving image by MPEG, an image used for motion prediction is displayed on an image monitor so that a moving portion is reduced. You can check in advance how it will be recorded.

According to the fourth aspect of the present invention, in the image pickup recording apparatus with a display monitor for performing compression recording, the degree of deterioration of image quality due to compression is confirmed in advance by selecting display of a compressed image and an image before compression. it can.

According to a fifth aspect of the present invention, in the image pickup recording apparatus with a display monitor for performing compression recording, when the monitor size is reduced, the amount of noise addition is increased so that the amount of image deterioration can be confirmed without being restricted by the monitor size. This facilitates design changes to models with different monitor sizes.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating the principle of adding noise according to the present invention.

FIG. 2 is a block diagram illustrating a principle of displaying an MPEG moving image according to the present invention.

FIG. 3 is a block diagram of the first embodiment of the present invention.

FIG. 4 is a block diagram of a second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 101 Image input unit 102 Image processing unit 103 Main memory 104 DSP 105 Noise amount control 106 Noise addition circuit 107 Image display unit

Claims (5)

[Claims] 1. An image capturing and recording apparatus with a display monitor for performing compression recording, comprising: noise generating means for generating image noise corresponding to a compression ratio; and noise adding means for adding the image noise to a monitor signal. An imaging recording device with a display monitor. 2. The imaging and recording apparatus with a display monitor according to claim 1, wherein said noise generating means is a block noise generating means for generating block noise corresponding to a compression ratio. 3. An image capturing and recording apparatus with a display monitor, wherein an image used for motion prediction is displayed on an image monitor, wherein the image is recorded by compressing a captured moving image by MPEG and recording. 4. An imaging and recording apparatus with a display monitor according to claim 1, wherein a display of a compressed image and an image before compression can be selected in an imaging and recording apparatus with a display monitor that performs compression recording. Recording device. 5. An imaging and recording apparatus with a display monitor according to claim 1, wherein in the imaging and recording apparatus with a display monitor performing compression recording, the noise addition amount is increased when the monitor size is reduced. Recording device.