JP4552677B2 - Encoding apparatus and method, decoding apparatus and method, information processing system, recording medium, and program - Google Patents

Description

The present invention relates to an encoding device and method, a decoding device and method, an information processing system, a recording medium, and a program, and in particular, encoding that can suppress unauthorized duplication of content data using an analog signal. The present invention relates to an apparatus and method, a decoding apparatus and method, an information processing system, a recording medium, and a program.

  Conventionally, in recording and transmission of image data, audio data, and the like, processing such as information encoding and decoding is usually performed.

  FIG. 1 shows a configuration example of a conventional image processing system. The image processing system 10 processes an encoded digital image signal Vcd, which is an encoded digital image signal, and outputs an analog image signal Van, and an analog image signal Van output from the playback device 11. A display device 12 for displaying an image and an encoding device 13 for encoding an analog image signal Van output from the playback device 11 and recording the encoded digital image signal Vcd on a recording medium are provided.

  The playback device 11 includes a decoding unit 21 and a D / A (Digital / Analog) conversion unit 22 (hereinafter referred to as D / A 22). The decoding unit 21 decodes an encoded digital image signal Vcd read from a recording medium such as an optical disk (not shown). The D / A 22 converts the decoded digital image signal Vdg into an analog image signal Van.

  The playback device 11 supplies the analog image signal Van to the display device 12 and the encoding device 13.

  The display device 12 has a display 23. The display 23 is configured by, for example, a CRT (Cathode-Ray Tube) display, an LCD (Liquid Crystal Display), or the like. The display device 12 displays the analog image signal Van supplied from the playback device 11 on the display 23.

  The encoding device 13 includes an A / D (Analog / Digital) conversion unit 24 (hereinafter referred to as A / D 24), an encoding unit 25, and a recording unit 26. The A / D 24 converts the analog image signal Van supplied from the playback device 11 into a digital signal, and generates a digital image signal Vdg. The encoding unit 25 encodes the digital image signal Vdg to generate an encoded digital image signal Vcd. The recording unit 26 includes, for example, a hard disk, a semiconductor memory, or a DVD (Digital Versatile Disc) drive, and records the encoded digital image signal Vcd generated by the encoding unit 25 on those recording media.

  That is, the image processing system 10 receives the encoded digital image signal Vcd, reproduces the analog image signal Van from the encoded digital image signal Vcd, displays an image, or regenerates the reproduced analog image signal Van. This is a system for encoding and recording an encoded digital image signal Vcd on a recording medium.

  As described above, since the image processing system 10 generates the analog image signal Van, there is a possibility that the image processing system 10 may be used for unauthorized duplication (illegal copy) using the analog image signal Van.

  That is, since the digital copyright protection function does not operate on the analog image signal Van, the encoding device 13 reproduces the original encoded digital image signal Vcd by digitizing and encoding the analog image signal Van. Can be recorded.

  Conventionally, in order to prevent unauthorized copying using such an analog image signal Van, when copyright protection is provided, the analog image signal Van is scrambled or the analog image signal Van is prohibited from being output. Has been proposed (see, for example, Patent Document 1).

  In addition, by providing a noise information generation unit in one or both of the playback device 11 and the encoding device 13 and embedding noise information in the digital video data that cannot be identified at the time of image playback by one processing, the copy itself is Although it is possible, a digital video apparatus has been proposed in which an image deteriorates remarkably when it is repeated a plurality of times, thereby substantially limiting the number of copies (see, for example, Patent Document 2).

  However, for example, as in Patent Document 1 described above, the reproduction apparatus 11 prevents unauthorized copying by scrambled and outputting the analog image signal Van or prohibiting the output of the analog image signal Van. In the case of this method, there is a problem that the display device 12 cannot display a normal image on the display 23.

  For example, when the playback device 11 scrambles and outputs the analog image signal Van, it is necessary to provide the display device 12 with a function for displaying a normal image corresponding to the scramble function.

  In addition, as in Patent Document 2 described above, in the case where noise information is embedded in a digital image signal by a decoding unit on the reproduction side or an encoding unit on the recording side, a noise information generation unit and a circuit for embedding the noise information are required. There is a problem that the circuit scale increases.

  Therefore, a method for preventing unauthorized copying using an analog image signal without causing inconvenience such as an image not being displayed or an increase in circuit scale has been proposed by the present applicant (for example, (See Patent Document 3).

JP 2001-245270 A Japanese Patent Laid-Open No. 10-289522 Japanese Patent Application Laid-Open No. 2004-289685

  In the method described in Patent Document 3 described above, attention is paid to analog noise such as phase shift of the digital image signal obtained by A / D conversion of the analog image signal, and attention is paid to analog noise for the digital image signal. Encoding does not degrade the quality of the image before copying, making it impossible to copy while maintaining good quality, thereby preventing unauthorized copying using analog image signals, In recent years when distribution has become common, as described above, there has been a demand for a proposal of another method for preventing unauthorized copying.

  The present invention has been made in view of such a situation, and makes it possible to suppress unauthorized duplication of content data using an analog signal.

An encoding apparatus according to the present invention is an encoding apparatus that encodes input image data including analog distortion, and includes a blocking unit that divides each frame image of the input image data into a plurality of blocks, A plurality of pixels at the peripheral edge of each block obtained by blocking by the blocking unit is a specific pixel, a group of specific pixels adjacent to each other among all pixel groups not limited to the specific pixel, and the group Vector quantization means for vector-quantizing the pixel value of the specific pixel every time, and in each block, the specific value in the block based on the pixel value of the specific pixel vector-quantized by the vector quantization means Prediction means for predicting the pixel value of each pixel other than the pixel, and prediction by the prediction means for each pixel other than the specific pixel in the block A difference calculating unit that calculates a difference between a predicted pixel value that is a pixel value obtained and a pixel value in the input image data, and differential encoding that encodes the difference obtained by the difference calculating unit for each block Means.

It said vector quantization means may be a specific pixel of the four corners of the pixels in each block.

It said predicting means, the pixel values of the pixels other than the specific pixel in the block, the pixel values of the specific pixel, it is the this predicted using the distance to each particular pixel.
The prediction means can set the pixel value of each pixel other than the specific pixel in the block to the pixel value of the specific pixel closest to the pixel.

  The difference calculation unit may further set the difference of the specific pixel to “0”, and the difference encoding unit may encode the difference of all the pixels in the block including the specific pixel.

  The difference encoding means includes an orthogonal transform means for orthogonally transforming the difference obtained by the difference calculating means, a quantization means for quantizing the coefficient data obtained by orthogonally transforming the difference by the orthogonal transform means, and quantization And variable length coding means for variable length coding the quantized coefficient data obtained by quantizing the coefficient data by the means.

  The orthogonal transform means may perform discrete sine transform on the difference.

  Selection code information which is information related to a code corresponding to a vector quantization result of a group of specific pixels selected by the vector quantization means, and encoded data obtained by encoding a difference by the difference encoding means Can be further provided with output means for outputting the signal to the outside of the encoding device.

A / D conversion of analog signal input image data to which analog noise is added by noise adding means for adding analog noise, which is a noise component to the analog component, to analog image input image data, A / D conversion means for obtaining input image data of digital data, and the blocking means includes a plurality of frame images of the input image data of digital data obtained by A / D conversion by the A / D conversion means. it can be blocked by dividing the block.

An encoding method according to the present invention is an encoding method of an encoding device that encodes input image data including analog distortion, and the blocker of the encoding device generates a plurality of frame images of the input image data. All the pixel groups that are not limited to the specific pixels, and the pixel quantization unit of the encoding device sets the plurality of pixels at the peripheral edge of each block obtained as a specific pixel. Specific pixel groups adjacent to each other in a group, the pixel value of the specific pixel is vector-quantized for each group, and the predicting means of the encoding device performs the vector quantization of the specific pixel in each block. Based on the pixel value, the pixel value of each pixel other than the specific pixel in the block is predicted, and the difference calculation unit of the encoding device is a unit other than the specific pixel in the block. For each pixel, a difference between a predicted pixel value that is a predicted pixel value and a pixel value in the input image data is calculated, and the difference encoding unit of the encoding device calculates the obtained difference for each block. Is encoded.

According to a first recording medium of the present invention, there is provided a blocking unit that blocks a computer that encodes input image data including analog distortion by dividing each frame image of the input image data into a plurality of blocks, and the block A plurality of pixels at the peripheral edge of each block obtained by making into a block by the converting means are specified pixels, and among all pixel groups not limited to the specified pixels, adjacent specific pixel groups are grouped, and for each group Vector quantization means for vector-quantizing the pixel value of the specific pixel, and, in each block, based on the pixel value of the specific pixel vector-quantized by the vector quantization means, other than the specific pixel in the block Prediction means for predicting the pixel value of each of the pixels, and prediction by the prediction means for each pixel other than the specific pixel in the block A difference calculating unit that calculates a difference between a predicted pixel value that is a pixel value obtained and a pixel value in the input image data, and differential encoding that encodes the difference obtained by the difference calculating unit for each block A program for functioning as a means is recorded.

According to a first program of the present invention, there is provided a blocking unit that blocks a computer that encodes input image data including analog distortion by dividing each frame image of the input image data into a plurality of blocks, and the blocking A plurality of pixels at the peripheral edge of each block obtained by the block formation as a specific pixel, a specific pixel group adjacent to each other among all pixel groups not limited to the specific pixel as a group, and for each group Vector quantization means for vector-quantizing the pixel value of the specific pixel, and in each block, based on the pixel value of the specific pixel that has been vector quantized by the vector quantization means, other than the specific pixel in the block Prediction means for predicting the pixel value of each pixel, and each pixel other than the specific pixel in the block is predicted by the prediction means. A difference calculating unit that calculates a difference between a predicted pixel value that is a pixel value that has been generated and a pixel value in the input image data; and differential encoding that encodes the difference obtained by the difference calculating unit for each block It functions as a means.

The decoding device of the present invention is a decoding device that decodes encoded data obtained by encoding image data including analog distortion by an encoding device, and a peripheral portion of each block of each frame image of the image data A plurality of pixels as specific pixels, and among all pixel groups not limited to the specific pixels, adjacent specific pixel groups are grouped, and for each group, pixel values of the specific pixels are vector quantized, A pixel value of each pixel other than the specific pixel in the block is predicted based on a pixel value of the specific pixel vector-quantized in the block, and a predicted pixel value for each pixel other than the specific pixel in the block A difference with a pixel value in the image data is calculated, and the result of vector quantization of the specific pixel is obtained from the encoded data obtained by encoding the difference for each block. Separating means for separating selected code information, which is information relating to the code selected as: an inverse vector quantizing means for inverse vector quantizing the selected code information separated from the encoded data by the separating means; Prediction means for predicting the pixel value of each pixel other than the specific pixel in the block including the specific pixel, using the pixel value of the specific pixel obtained by inverse vector quantization by the vector quantization means; Differential decoding means for decoding the encoded data from which the selection code information has been separated by the separation means; prediction pixel values obtained by the prediction means for each pixel other than the specific pixel; and the difference decoding means Pixel value adding means for adding the difference obtained by decoding.

  The specific pixels may be pixels at the four corners of each block.

  The pixel value adding means may perform addition after setting a difference between specific pixels to “0”.

  The pixel value adding means can rearrange the input pixel values of each pixel obtained as an addition result in raster order for each block.

The difference decoding means includes variable length decoding means for variable-length decoding the sign-coded data, inverse quantization of inverse quantizing the quantized coefficient data encoded data obtained by the variable length decoding by the variable length decoding unit means, Ru and an inverse orthogonal transform means for inverse orthogonal transform coefficient data obtained by the inverse quantization quantized coefficient data by the inverse quantization means.

  The orthogonal transform means may perform inverse discrete sine transform on the coefficient data.

Digital image data constituted by the pixel values obtained by the pixel value adding means is D / A converted and converted into analog signals, and the digital image data is converted by the D / A conversion means. A noise adding means for adding analog noise, which is a noise component with respect to the analog component, to the analog signal obtained by D / A conversion, and the analog signal to which the analog noise is added by the noise adding means is output. Output means .

The decoding method of the present invention is a decoding method of a decoding apparatus for decoding encoded data obtained by encoding image data including analog distortion by an encoding apparatus, wherein the separation means of the decoding apparatus includes the image A plurality of pixels at the peripheral edge of each block of each frame image of data is set as a specific pixel, and among all pixel groups not limited to the specific pixel, adjacent specific pixel groups are grouped, and the specific pixel group is specified for each group. The pixel value of the pixel is vector-quantized, and the pixel value of each pixel other than the specific pixel in the block is predicted based on the pixel value of the specific pixel vector-quantized in each block, and the pixel value in the block For each pixel other than the specific pixel, the difference between the predicted pixel value and the pixel value in the image data is calculated, and whether the difference is the encoded data encoded for each block , Separating selected code information that is information relating to a code selected as a result of vector quantization of the specific pixel, and the inverse vector quantization means of the decoding device converts the selected code information separated from the encoded data inverse vector quantization, prediction means of the decoding apparatus, using a pixel value of the specific pixel obtained by being inverse vector quantization, in the block including the specified pixel, a pixel of each pixel other than the specific pixel Predicting the value, the differential decoding means of the decoding device decodes the encoded data from which the selection code information is separated, and the pixel value adding means of the decoding device obtains each pixel other than the specific pixel. The obtained prediction pixel value and the difference obtained by decoding are added .

According to a second recording medium of the present invention, there is provided a computer for decoding encoded data obtained by encoding image data including analog distortion by an encoding device, and a peripheral portion of each block of each frame image of the image data. A plurality of pixels as specific pixels, and among all pixel groups not limited to the specific pixels, adjacent specific pixel groups are grouped, and for each group, pixel values of the specific pixels are vector quantized, A pixel value of each pixel other than the specific pixel in the block is predicted based on a pixel value of the specific pixel vector-quantized in the block, and a predicted pixel value for each pixel other than the specific pixel in the block A difference from a pixel value in the image data is calculated, and the vector quantization of the specific pixel is performed from the encoded data in which the difference is encoded for each block. Separation means for separating selected code information that is information relating to the selected code as a result, inverse vector quantization means for inverse vector quantization of the selected code information separated from the encoded data by the separation means, Prediction means for predicting the pixel value of each pixel other than the specific pixel in the block including the specific pixel, using the pixel value of the specific pixel obtained by inverse vector quantization by the inverse vector quantization means; Differential decoding means for decoding the encoded data from which the selection code information has been separated by the separation means; a predicted pixel value obtained by the prediction means for each pixel other than the specific pixel; and the differential decoding means The program for functioning as a pixel value addition means which adds the difference obtained by decoding is recorded.

According to a second program of the present invention, a computer that decodes encoded data obtained by encoding image data including analog distortion by an encoding device is provided on a peripheral portion of each block of each frame image of the image data. A plurality of pixels are specified pixels, a specified pixel group adjacent to each other among all pixel groups not limited to the specified pixel is grouped, and the pixel value of the specified pixel is vector-quantized for each group, The pixel value of each pixel other than the specific pixel in the block is predicted based on the pixel value of the specific pixel that is vector quantized in step, and the predicted pixel value and the pixel value for each pixel other than the specific pixel in the block A difference from a pixel value in the image data is calculated, and from the encoded data obtained by encoding the difference for each block, a vector quantum of the specific pixel is calculated. Separating means for separating selected code information that is information relating to the code selected as a result of the above, and inverse vector quantizing means for inverse vector quantizing the selected code information separated from the encoded data by the separating means; Prediction means for predicting the pixel value of each pixel other than the specific pixel in the block including the specific pixel, using the pixel value of the specific pixel obtained by inverse vector quantization by the inverse vector quantization means Differential decoding means for decoding the encoded data from which the selection code information has been separated by the separation means, predicted pixel values obtained by the prediction means for each pixel other than the specific pixel, and the differential decoding It is made to function as a pixel value addition means which adds the difference obtained by decoding by the means.

The first information processing system of the present invention includes an encoding unit and a decoding unit, and information processing that degrades the image data when the encoding process and the decoding process are repeated for image data including analog distortion. In the system, the encoding unit includes a block unit that divides each frame image of the image data into a plurality of blocks, and a peripheral portion of each block obtained by the block unit. A vector quantizing unit that sets a plurality of pixels as specific pixels, groups specific pixel groups adjacent to each other among all pixel groups not limited to the specific pixels, and vector-quantizes pixel values of the specific pixels for each group; In each block, based on the pixel value of the specific pixel vector-quantized by the vector quantization means, the specific pixel in the block A prediction unit that predicts a pixel value of each pixel outside, a predicted pixel value that is a pixel value predicted by the prediction unit for each pixel other than the specific pixel in the block, and a pixel value in the image data Difference calculation means for calculating the difference between the difference calculation means and difference encoding means for encoding the difference obtained by the difference calculation means for each block.

A second information processing system according to the present invention includes an encoding unit and a decoding unit, and information processing in which the image data deteriorates when the encoding process and the decoding process are repeated for image data including analog distortion. In the system, the decoding unit includes a plurality of pixels at a peripheral portion of each block of each frame image of the image data as a specific pixel, and a specific pixel group adjacent to each other among all the pixel groups not limited to the specific pixel. A pixel value of each pixel other than the specific pixel in the block based on the pixel value of the specific pixel that is group-quantized, and the pixel value of the specific pixel is vector-quantized for each group A value is predicted, a difference between the predicted pixel value and a pixel value in the image data is calculated for each pixel other than the specific pixel in the block, and the difference is Separation means for separating selected code information, which is information relating to a code selected as a result of vector quantization of the specific pixel, from the encoded data encoded for each block, and from the encoded data by the separation means Inverse vector quantization means for performing inverse vector quantization on the separated selection code information, and using the pixel value of the specific pixel obtained by inverse vector quantization by the inverse vector quantization means, A prediction unit that predicts a pixel value of each pixel other than the specific pixel in a block including the difference decoding unit that decodes the encoded data from which the selection code information is separated by the separation unit; For each pixel, a pixel value that adds the predicted pixel value obtained by the predicting means and the difference obtained by decoding by the differential decoding means And a calculation means.

In the encoding apparatus and method, the first recording medium, and the first program according to the present invention, each frame image of the input image data is divided into a plurality of blocks, and each block image is obtained by being blocked. A plurality of pixels at the peripheral edge of the block are specified pixels, a specific pixel group adjacent to each other among all pixel groups not limited to a specific pixel is grouped, and the pixel value of the specific pixel is vector quantized for each group, In each block, the pixel value of each pixel other than the specific pixel in the block is predicted based on the pixel value of the specific pixel subjected to vector quantization, and the predicted pixel value for each pixel other than the specific pixel in the block The difference between the predicted pixel value and the pixel value in the input image data is calculated, and the obtained difference is encoded for each block.

In the decoding apparatus and method, the second recording medium, and the second program of the present invention, a plurality of pixels at the peripheral edge of each block of each frame image of the image data are set as specific pixels, and are not limited to specific pixels. Specific pixel groups adjacent to each other in the pixel group are grouped, and the pixel value of the specific pixel is vector-quantized for each group, and the specific value in the block is determined based on the pixel value of the specific pixel vector-quantized in each block. Encoding in which the pixel value of each pixel other than the pixel is predicted, the difference between the predicted pixel value and the pixel value in the image data is calculated for each pixel other than the specific pixel in the block, and the difference is encoded for each block Selection code information that is information related to a code selected as a result of vector quantization of a specific pixel is separated from the data, and the selection code is separated from the encoded data. Information is subjected to inverse vector quantization, and the pixel value of a specific pixel obtained by inverse vector quantization is used to predict the pixel value of each pixel other than the specific pixel in the block including the specific pixel. The encoded data from which the information is separated is decoded, and for each pixel other than the specific pixel, the obtained predicted pixel value and the difference obtained by decoding are added.

In the first information processing system of the present invention, the encoding unit divides each frame image of the image data into a plurality of blocks and blocks the plurality of blocks, and a plurality of peripheral portions of each block obtained by the blocking are obtained. A pixel is a specific pixel, and among all pixel groups that are not limited to a specific pixel, a specific pixel group adjacent to each other is grouped, and the pixel value of the specific pixel is vector-quantized for each group. Based on the pixel value of the specified pixel, the pixel value of each pixel other than the specific pixel in the block is predicted, and for each pixel other than the specific pixel in the block, a predicted pixel value that is a predicted pixel value and an image The difference with the pixel value in the data is calculated, and the obtained difference is encoded for each block.

In the second information processing system of the present invention, a plurality of pixels at the peripheral edge of each block of each frame image of the image data are set as specific pixels by the decoding unit , and each other in all pixel groups not limited to the specific pixels. Adjacent specific pixel groups are grouped, and the pixel value of the specific pixel is vector-quantized for each group, and each pixel other than the specific pixel in the block is based on the pixel value of the specific pixel vector-quantized in each block. The pixel value is predicted, the difference between the predicted pixel value and the pixel value in the image data is calculated for each pixel other than the specific pixel in the block, and the specific pixel is calculated from the encoded data obtained by encoding the difference for each block. The selected code information, which is information about the code selected as a result of vector quantization, is separated, and the selected code information separated from the encoded data is inverse vector quantized. The pixel value of the specific pixel obtained by inverse vector quantization is used to predict the pixel value of each pixel other than the specific pixel in the block including the specific pixel, and the selection code information is separated. The decoded data is decoded, and for each pixel other than the specific pixel, the obtained predicted pixel value and the difference obtained by decoding are added.

  According to the present invention, unauthorized duplication of content data using an analog signal can be suppressed. In particular, without causing inconveniences such as no image being displayed or an increase in circuit scale, the second and subsequent encoding and decoding processes significantly degrade image data and suppress unauthorized copying using analog signals. can do.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 2 is a diagram illustrating a configuration example of an image processing system to which the present invention is applied.

  An image processing system 30 shown in FIG. 2 includes a playback device 31, a display device 32, and an encoding device 33, processes an encoded digital image signal to generate an analog image signal, and generates the image. Or the analog image signal is encoded again and the encoded digital image signal is recorded on a recording medium.

  The playback device 31 includes a decoding unit 41 and a D / A (Digital / Analog) conversion unit 42 (hereinafter referred to as D / A 42). The decoding unit 41 decodes the encoded digital image signal Vcd0 reproduced from a recording medium such as an optical disk (not shown) to generate a digital image signal Vdg0. Details of the decoding unit 41 will be described later. The D / A 42 converts the digital image signal Vdg0 into an analog signal, and generates an analog image signal Van1. The playback device 31 supplies the analog image signal Van1 to the display device 32 and the encoding device 33.

  This analog image signal Van1 is accompanied by analog distortion. The analog distortion includes, for example, distortion caused by removing a high frequency component when converted to an analog signal by the D / A 42, and distortion caused by a phase shift of the signal when converted to an analog signal by the D / A 42. Etc. are included. As a method for evaluating the image degradation due to the analog distortion, for example, there are S / N (Signal-to-Noise) evaluation, visual evaluation (evaluation of visual deterioration), and the like. This analog distortion may be naturally occurring that usually occurs in an actual apparatus, or may be intentionally generated as described later.

  The display device 32 includes a display 43 such as a CRT (Cathode Ray Tube) display, LCD (Liquid Crystal Display), or the like. When the analog image signal Van1 output from the playback device 31 is acquired, the image is displayed on the display 43. To display.

  The encoding device 33 includes an A / D (Analog / Digital) conversion unit 44 (hereinafter referred to as A / D 44), an encoding unit 45, a recording unit 46, a decoding unit 41, a D / A 42, and a display 43. ing. The encoding device 33 converts the analog image signal Van1 supplied from the playback device 31 in the A / D 44 into a digital image signal Vdg1, then encodes it in the encoding unit 45, and encodes the encoded digital image in the recording unit 46. The signal Vcd1 is recorded on the recording medium. Further, when the encoding device 33 re-decodes the encoded digital image signal Vcd1 in the decoding unit 41 and D / A converts the decoded digital image signal Vdg2 in the D / A 42 to generate the analog image signal Van2, the image Is displayed on the display 43.

  The A / D 44 converts the analog image signal Van1 output from the playback device 31 into a digital signal, and generates a digital image signal Vdg1. The encoding unit 45 encodes the digital image signal Vdg1 to generate an encoded digital image signal Vcd1. Details of the encoding unit 45 will be described later. The recording unit 46 includes, for example, a hard disk, a semiconductor memory, or a DVD (Digital Versatile Disc) drive, and records the encoded digital image signal Vcd1 generated by the encoding unit 45 on those recording media.

  The decoding unit 41 of the encoding device 33 decodes the encoded digital image signal Vcd1 generated by the encoding unit 45, and generates a digital image signal Vdg2. The D / A 42 of the encoding device 33 converts the digital image signal Vdg2 decoded by the decoding unit 41 of the encoding device 33 into an analog image signal Van2. The display 43 of the encoding device 33 displays the image of the analog image signal Van2.

  Although details will be described later, the encoding unit 45 of the encoding device 33 uses the analog distortion included in the analog image signal Van1 to significantly improve the quality (image quality) of the image signal content. Degrade and encode. In addition, the decoding unit 41 of the reproduction device 31 and the encoding device 33 also decodes the encoded digital image signal input by the decoding method corresponding to the encoding unit 45.

  That is, in FIG. 2, identification numbers are assigned to the analog image signal Van, the digital image signal Vdg, and the encoded digital image signal Vcd depending on the position of each signal. This indicates that the signal is different from other similar signals. For example, in the case of the analog image signal Van, the analog image signal Van2 output from the D / A 42 of the encoding device 33 encodes the analog image signal Van2 while degrading the image quality using analog distortion, and the encoding device 45. Is a signal of image information that is generated by using a signal after passing through the decoding unit 46 corresponding to the above and deteriorated from the analog image signal Van1 output from the D / A 42 of the reproducing device 31. Similarly, the image of the digital image signal Vdg2 is also deteriorated from the image of the digital image signal Vdg1, and the image of the digital image signal Vdg1 is also deteriorated from the image of the digital image signal Vdg0. The same applies to the encoded digital image signal Vcd, and the image of the encoded digital image signal Vcd1 is more deteriorated than the encoded digital image signal Vcd0.

  As described above, in the image processing system 30, the playback device 31 outputs the analog image signal Van1, and the display device 32 displays the image. The encoding device 33 uses the analog image signal Van1 to copy the image data. In this case, since the image is deteriorated, duplication using the analog image signal Van can be suppressed.

  Next, the detail of each part is demonstrated. First, the encoding unit 45 of the encoding device 33 will be described. FIG. 3 is a block diagram illustrating a detailed configuration example of the encoding unit 45 of FIG. The encoding unit 45 includes a blocking unit 61, a vector quantization (VQ) unit 62 (hereinafter referred to as a VQ unit 62), a prediction unit 63, a residual calculation unit 64, a residual encoding unit 65, and an output unit 66. have.

  The blocking unit 61 divides the frame image data included in the input digital image signal Vdg1 into blocks of a predetermined size. The blocking unit 61 divides the frame image data (the image signal of the effective screen) into blocks (BL) having a size of 8 pixels × 8 pixels, for example, as shown in FIG. In FIG. 4, white circles indicate pixel data constituting the blocks, and the horizontal and vertical straight lines indicate that part of the frame image data is 3 blocks in the horizontal direction and 2 blocks in the vertical direction (BL71 to BL76). (Total 6 blocks). FIG. 4 is a schematic diagram showing how the frame image data is blocked, and does not show the actual contents of the frame image data. 3 supplies the image data thus blocked to the VQ unit 62 for each block.

  The VQ unit 62 specifies a plurality of pixels at the peripheral portion of each block obtained in the blocking unit 61 as specific pixels, and groups a plurality of specific pixels existing in each frame image for each predetermined range according to the position. And vector quantization of the pixel value of the specific pixel for each group. FIG. 5 shows details of the VQ unit 62. 5, the VQ unit 62 includes a specific pixel data extraction unit 81, a vector generation unit 82, a pixel pattern-specific code book 83, and a VQ code determination unit 84.

  The specific pixel data extraction unit 81 extracts pixel data of specific pixels determined in advance from the pixel data for each block supplied from the blocking unit 61, and supplies it to the vector generation unit 82. For example, as illustrated in FIG. 6, the specific pixel data extraction unit 81 sets the four corner pixels of each block as specific pixels and supplies the pixel data to the vector generation unit 82. In the case of FIG. 6, the specific pixel data extraction unit 81 extracts the pixels 91A to 91D as specific pixels for BL71, extracts the pixels 92A to 92D as specific pixels for BL72, Then, the pixels 93A to 93D are extracted as specific pixels, the pixels 94A to 94D are extracted as specific pixels to BL74, the pixels 95A to 95D are extracted as specific pixels to BL75, and BL76 On the other hand, the pixels 96A to 96D are extracted as specific pixels. The specific pixel data extraction unit 81 similarly extracts specific pixels for other blocks.

  The specific pixel may be a pixel at any position in the block. However, in order to efficiently degrade the image quality using the phase shift of the analog signal as described later, a plurality of pixels at the peripheral portion of each block are used. These pixels (for example, pixels at the four corners of each block) are preferably specified pixels.

  The vector generation unit 82 holds the pixel data of the specific pixel extracted by the specific pixel data extraction unit 81, and generates vector data for each pixel data of the pixel whose blocks are closest to each other. That is, the vector generation unit 82 groups a plurality of specific pixels existing in the frame image for each predetermined range according to the position, and generates vector data from the pixel values of the specific pixels in each group. For example, when the specific pixel data extraction unit 81 specifies the four corner pixels of each block as the specific pixel, the vector generation unit 82 sets one set of adjacent specific pixels, that is, adjacent corner pixels as one Group data is generated as a group.

  The vector generation unit 82 supplies the generated vector data to the VQ code determination unit 84 and supplies pixel pattern information indicating the type of the vector data to the pixel pattern-specific code book 83.

  For example, in the case of FIG. 6, the pattern of the group of specific pixels extracted by the specific pixel data extraction unit 81 includes a pattern composed of four pixels such as the pixel 91D, the pixel 92C, the pixel 94B, and the pixel 95A, and the pixel 91B. In addition, there are three patterns including a pattern composed of two pixels like the pixel 92A and a pattern composed of one pixel like the pixel 91A. That is, the specific pixels at the four corners of the frame image data are grouped by one pixel because the corners of the block are not adjacent to each other. Of the specific pixels located at the top, bottom, left, and right ends of the frame image data, The specific pixels excluding the specific pixels at the four corners are groups formed by two pixels because the pixels at the corners of the two blocks are adjacent to each other, and the specific pixels located at positions other than the upper, lower, left, and right ends of the frame image data are four. Since the corners of the blocks are adjacent to each other, the group is composed of four pixels.

  In FIG. 6, white circles or black circles indicate pixel data constituting the blocks, and horizontal and vertical straight lines indicate ranges of the respective blocks. FIG. 6 is a schematic diagram showing how pixel data of a specific pixel is extracted, and does not show the actual contents of frame image data.

  Returning to FIG. 5, the vector generation unit 82 supplies the vector data to the VQ code determination unit 84, and the vector so that the VQ code determination unit 84 can determine the correct VQ code corresponding to the vector data. Pixel pattern information indicating a data configuration is supplied to the pixel pattern-specific code book 83.

  In the code book 83 for each pixel pattern, a code book learned using, for example, the LBG algorithm or the like using many common images is stored in advance. This code book is generated and held for each pixel pattern (configuration). Based on the pixel pattern information supplied from the vector generation unit 82, the pixel pattern-specific code book 83 supplies a code book having a configuration corresponding to the vector data generated by the vector generation unit 82 to the VQ code determination unit 84. That is, for example, when the vector generation unit 82 generates vector data with the pixel 91D, the pixel 92C, the pixel 94B, and the pixel 95A as one group, the pixel pattern-specific codebook 83 includes four pixels based on the pixel pattern information. Is supplied to the VQ code determination unit 84.

  The VQ code determination unit 84 selects a code that minimizes the Euclidean distance from the vector data supplied from the vector generation unit 82 from among the code books supplied from the pixel pattern-specific code book 83, thereby obtaining the VQ code. Determine the code Vcdvq. The VQ code determination unit 84 supplies the VQ code as selection code information Vcdvq to the output unit 66 (FIG. 3) and supplies a representative value corresponding to the VQ code to the prediction unit 63 (FIG. 3).

  Returning to FIG. 3, the prediction unit 63 predicts pixel values of other pixels for each block from the representative values supplied from the VQ unit 62. As shown in FIG. 7, the prediction unit 63 predicts the value of each pixel in the block from the pixels at the four corners of the block (that is, the representative values supplied from the VQ unit 62). That is, when the prediction unit 63 performs prediction of the pixel 101, the pixel values (representative values obtained by vector quantization) of the pixels at the four corners of the block including the pixel 101 (pixels indicated by black circles in FIG. 7). ) To predict.

  For example, in FIG. 7, the pixel value at the upper left corner of the block including the pixel value 101 is A, the pixel value at the upper right corner is B, the pixel value at the lower left corner is C, and the pixel value at the lower right corner is D. And The pixel values A to D are all pixel values encoded by the VQ unit 62 (representative values obtained by vector quantization). The prediction unit 63 calculates distances a to d from the pixels at the four corners to the pixel 101, calculates the following expression (1), and calculates a predicted pixel value Z of the pixel 101.

  Since each value of the distance a to the distance d is determined in advance by the position of the pixel to be predicted (pixel 101 in the example of FIG. 7) in the block, the prediction unit 63 is supplied from the VQ unit 62. The predicted pixel value Z can be easily calculated simply by substituting the calculated representative value (pixel value A to pixel value D in the case of the example in FIG. 7) into Equation (1).

  In order to further simplify the calculation, the prediction unit 63 calculates the following expression (2), and the pixel value P of the pixel closest to the prediction target pixel among the four corner pixels of the prediction target pixel block: May be selected and the value may be set as the predicted pixel value Z.

  That is, the prediction unit 63 sets the predicted pixel value Z to the pixel value P of the pixel corresponding to the shortest distance from the distance a to the distance d. The pixel value P is selected from any one of the pixel values A to D.

  Therefore, in this case, it is possible to specify in advance which of the pixel values A to D is the predicted pixel value depending on the position of the pixel to be predicted. That is, the prediction unit 63 effectively performs the calculation of Expression (2) in advance, and directly predicts the representative values (pixel value A to pixel value D in the example of FIG. 7) supplied from the VQ unit 62. Since the pixel value Z can be set, the predicted pixel value Z of each pixel can be obtained more easily.

  In FIG. 7, white circles or black circles indicate pixel data constituting the block. FIG. 7 is a schematic diagram showing how pixels are predicted, and does not show the actual contents of image data.

  Returning to FIG. 3, the prediction unit 63 obtains a predicted pixel value for each pixel as described above. However, for the pixel values of the pixels at the four corners of each block, the representative value (encoded pixel value) itself supplied from the VQ unit 62 is the predicted pixel value. The prediction unit 63 supplies the predicted pixel value to the residual calculation unit 64.

  The residual calculation unit 64 calculates a difference (residual) between the predicted pixel value supplied from the prediction unit 63 and the digital image signal Vdg1 input to the encoding unit 45. At this time, when the residual calculation unit 64 calculates a residual (difference between the pixel value and the predicted pixel value) for the specific pixel processed in the VQ unit 62 (that is, a value other than “0” for the residual of the specific pixel). In the case of encoding by the residual encoding unit 65, the pixel value is affected by encoding distortion. For example, when the digital data is encoded again, the output of the VQ unit 62 changes. There is a fear. Therefore, in order to avoid such deterioration due to digital multi-encoding / decoding, the residual calculation unit 64 sets the residual (difference value) to “0” for the specific pixel.

  FIG. 8 is a block diagram illustrating a detailed configuration example of the residual calculation unit 64. In FIG. 8, the residual calculation unit 64 includes a pixel determination unit 111, a difference value calculation unit 112, a difference value setting unit 113, and a residual output unit 114.

  When the pixel determination unit 111 acquires the predicted pixel value from the prediction unit 63 and acquires the digital image signal Vdg1 input to the encoding unit 45, whether each pixel is a specific pixel (pixels at the four corners of the block). For the pixel determined to be a specific pixel, the determination result is supplied to the difference value setting unit 113, and for the pixel determined to be a pixel other than the specific pixel, the digital image of the pixel The pixel value and the predicted pixel value in the signal Vdg1 are supplied to the difference value calculation unit 112.

  The difference value calculation unit 112 calculates a difference value between the pixel value supplied from the pixel determination unit 111 and the predicted pixel value, and supplies the obtained difference value to the residual output unit 114. That is, the difference value calculation unit 112 calculates a difference value for pixels other than the four corner pixels (specific pixels) of each block and supplies the difference value to the residual output unit 114. The difference value setting unit 113 sets the difference value of the four corner pixels (specific pixels) of each block to “0” and supplies the difference value to the residual output unit 114.

  The residual output unit 114 outputs the difference value supplied from the difference value calculation unit 112 and the difference value setting unit 113 as a residual for each frame, and supplies the residual value to the residual encoding unit 65 (FIG. 3).

  Returning to FIG. 3, the residual encoding unit 65 encodes the residual (the difference value between the pixel value and the predicted pixel value in the digital image signal Vdg1) supplied from the residual calculation unit 114. At this time, the residual encoding unit 65 uses, for example, DST (Discrete Sine Transform), which is orthogonal transformation, because the values of the four corners of each block are “0” in the supplied residual. The residual encoding unit 65 performs DST conversion on the residual, quantizes it, encodes it to Huffman, and generates encoded data Vcddiff.

  FIG. 9 is a block diagram illustrating a detailed configuration example of the residual encoding unit 65. In FIG. 9, the residual encoding unit 65 includes a DST conversion unit 121, a quantization unit 122, and a Huffman encoding 123.

  The DST conversion unit 121 encodes the residual supplied from the residual calculation unit 114 for each block. The DST transform expresses a waveform by superimposing orthogonal sine waves, and is a kind of orthogonal transform. For example, the DST conversion unit 121 performs the DST conversion on a certain pixel column or row as shown in FIG. 10A, thereby converting the function of the pixel value into a waveform in which sine waves as shown in FIG. 10B are superimposed. Express.

  That is, if the pixel position shown in FIG. 10A is i, the base number shown in FIG. 10B is j, and the number of orthogonal transformation target pixels shown in FIG. Is expressed as a superposition of sine waves represented by the following formula (3).

  FIG. 10 illustrates an example of DST conversion in the case of one dimension, but the DST conversion unit 121 performs two-dimensional DST conversion on each block of the residual.

When performing DST conversion in two dimensions, the DST conversion unit 121 performs one-dimensional DST conversion in each of the horizontal direction and the vertical direction, as shown in FIG. That is, the horizontal pixel position (FIG. 11) is i, the horizontal base number is j, the vertical pixel position (FIG. 11) is k, the vertical base number is l (el), and the number of pixels in the horizontal direction was a N _h, and the number of pixels in the vertical direction and N _v, DST conversion unit 121 are expressed as a superposition of sine waves shown the function of the pixel values in equation (4) below.

  Since the residual values at the four corners are “0”, the values are concentrated at low frequencies in the data converted by DST. Accordingly, the DST conversion unit 121 can perform orthogonal transformation more efficiently than orthogonal transformation by DCT (Discrete Cosine Transform), for example.

  Returning to FIG. 9, the DST conversion unit 121 supplies the converted data to the quantization unit 122. The quantization unit 122 quantizes the transformed data using a quantization table, similarly to encoding using general orthogonal transform such as DCT. The quantization unit 122 supplies the quantized coefficient data obtained by the quantization to the Huffman coding unit 123. The Huffman encoder 123 encodes the quantized coefficient data of each block supplied from the quantizer 122 by Huffman encoding, and outputs the Huffman encoded data as encoded data Vcddiff as an output unit 66 (FIG. 3). To supply.

  In the above description, encoding is performed using the Huffman encoding method. However, the present invention is not limited to this, and any encoding may be used. The Huffman encoding method is a variable-length encoding method and can perform lossless compression, and thus can efficiently encode quantized coefficient data. In the following, the encoding process using the Huffman encoding method and the decoding process by the Huffman decoding method, which is a decoding method corresponding to the Huffman encoding, will be described. You may make it encode (decode) by methods other than (Huffman decoding method).

  The output unit 66 uses the selected code information Vcdvq supplied from the VQ unit 62 and the encoded data Vcddiff supplied from the residual encoding unit 65 as an encoded digital image signal Vcd1 as a recording unit 46 and a decoding unit 41 ( Both are supplied to FIG.

  Next, details of the decoding unit 41 of the reproduction device 31 and the encoding device 33 will be described. FIG. 12 is a block diagram illustrating a detailed configuration example of the decoding unit 41. In FIG. 12, the decoding unit 41 includes a data decomposition unit 151, an inverse vector quantization (VQ) unit 152 (hereinafter referred to as an inverse VQ unit 152), a prediction unit 153, a residual decoding unit 154, a pixel value addition unit 155, And a block disassembly unit 156.

  When the data decomposing unit 151 obtains the input encoded digital signal Vcd (Vcd0 in the case of the composite unit 41 of the reproducing device 31 and Vcd1 in the case of the decoding unit 41 of the encoding device 33), the data decomposing unit 151 selects it as encoded data Vcddiff. The code information Vcdvq is separated, and the selected code information Vcdvq is supplied to the inverse vector quantization (VQ) unit 152 (hereinafter referred to as the inverse VQ unit 152), and the encoded data Vcddiff is supplied to the residual decoding unit 154.

  Although not shown, the inverse VQ unit 152 has a code book similar to the pixel pattern-specific code book 83 of the VQ unit 62. When the selection code information Vcdvq is acquired from the data decomposition unit 151, the selection code A representative value corresponding to the code of the information Vcdvq is selected from the code book, and is output to the prediction unit 153. That is, the inverse VQ unit 152 calculates a representative value as a pixel value of the specific pixel based on the supplied selection code information Vcdvq, and supplies it to the prediction unit 153.

  The prediction unit 153 is configured in the same manner as the prediction unit 63 (FIG. 3) of the encoding unit 45, and performs the same processing as the prediction unit 63. That is, the prediction unit 153 predicts pixel values of pixels other than the specific pixel based on the pixel value of the specific pixel supplied from the inverse VQ unit 152 (representative value corresponding to the code of the selection code information Vcdvq) (prediction pixel). Value). For the specific pixel, the prediction unit 153 uses the representative value supplied from the inverse VQ unit 152 as the predicted pixel value. The prediction unit 153 supplies the predicted pixel value calculated as described above to the pixel value addition unit 155.

  The residual decoding unit 154 decodes the encoded data Vcddiff supplied from the data decomposing unit 151 by a method corresponding to the encoding method by the residual encoding unit 65 (FIG. 3) of the encoding unit 45. For example, when the encoding of the residual encoding unit 65 is, for example, DST, the residual decoding unit 154 performs variable length decoding for decoding an entropy encoded signal (for example, a Huffman encoded signal), and performs quantum quantization for each block. The quantized coefficient data is inversely quantized to calculate coefficient data of each block, and the coefficient data of each block is subjected to inverse DST for each block to obtain pixel data (residual). .

  FIG. 13 is a block diagram illustrating a detailed configuration example of the residual decoding unit 154.

  In FIG. 13, the residual decoding unit 154 includes a Huffman decoding unit 161, an inverse quantization unit 162, and an IDST (Inverse Discrete Sine Transform) conversion unit 163.

  When the Huffman decoding unit 161 acquires the encoded data Vcddiff supplied from the data decomposing unit 151 (FIG. 12), the Huffman encoding unit 123 (FIG. 9) of the residual encoding unit 65 converts the encoded data Vcddiff into the Huffman encoding unit 123. When decoding is performed by a decoding method corresponding to the Huffman encoding method and quantized coefficient data is obtained, the quantized coefficient data is supplied to the inverse quantization unit 162.

  The inverse quantization unit 162 has a quantization table (none of which is shown) similar to the quantization table of the quantization unit 122 (FIG. 9) of the residual encoding unit 65, and is supplied from the Huffman decoding unit 161. The quantized coefficient data is inversely quantized using the quantization table, and coefficient data of each block, which is DST-converted pixel value data, is obtained. The inverse quantization unit 162 supplies the coefficient data to the IDST conversion unit 163.

  When the IDST conversion unit 163 acquires the coefficient data supplied from the inverse quantization unit 162, the DST conversion process by the DST conversion unit 121 (FIG. 9) of the residual encoding unit 65 is performed on the coefficient data for each block. Inverse DST conversion processing is performed by a method corresponding to the above to obtain pixel data of each block. The IDST conversion unit 163 supplies the pixel data (residual) to the pixel value addition unit 155 (FIG. 12).

  Returning to FIG. 12, the residual decoding unit 154 calculates the residual from the encoded data Vcddiff in this way, and supplies the obtained residual to the pixel value adding unit 155.

  The pixel value adding unit 155 adds the prediction pixel value supplied from the prediction unit 153 of the same pixel to each pixel data of the residual supplied from the residual decoding unit 154. At this time, the pixel value addition unit 155 does not perform a residual addition process on the pixel data (specific pixel) decoded by the inverse VQ unit 152.

  FIG. 14 is a block diagram showing a detailed configuration example of the pixel value adding unit 155. As shown in FIG. In FIG. 14, the pixel value addition unit 155 includes a pixel determination unit 171, a residual setting unit 172, an addition value calculation unit 173, and an order alignment unit 174.

  Based on the prediction pixel value supplied from the prediction unit 153 and the residual supplied from the residual decoding unit 154, the pixel determination unit 171 determines whether the pixel to be processed is a pixel (specific pixel) at the four corners of the block. Determine whether or not. When the pixel determination unit 171 determines that the pixel to be processed is a pixel (specific pixel) at the four corners of the block, the pixel determination unit 171 supplies the determination result to the residual setting unit 172, and the pixel to be processed is at the four corners of the block. If it is determined that the pixel is not a pixel (specific pixel), the residual is supplied to the added value calculation unit 173.

  When the residual setting unit 172 obtains a determination result that the pixel to be processed is a pixel at the four corners of the block (specific pixel) from the pixel determination unit 171, in order to avoid deterioration due to digital multi-encoding / decoding, The residual of the pixel is set to a predetermined value (for example, “0”), and the residual is supplied to the addition value calculation unit 173.

  The addition value calculation unit 173 adds the residual supplied from the pixel determination unit 171 or the residual setting unit 172 to the predicted pixel value, and supplies the addition result to the order alignment unit 174.

  The order arranging unit 174 rearranges the order of the pixel values supplied from the addition value calculating unit 173 in the order of raster scanning. Then, each pixel value (image data) in which the order is rearranged is supplied to the block decomposing unit 156 (FIG. 12).

  As described above, the pixel value addition unit 155 sets the residual value to “0” for the pixels (specific pixels) at the four corners of the block, and does not add the residual to the predicted pixel value. By doing so, the pixel value adding unit 155 can suppress encoding distortion and suppress deterioration due to digital multi-encoding / decoding.

  Returning to FIG. 12, the block decomposing unit 156 returns the pixel data of each block to the position before blocking, and outputs it as a digital image signal Vdg (Vdg0 in the case of the playback device 31 and Vdg2 in the case of the encoding device 33).

  Next, processing executed by each device of the image processing system 30 as described above will be described.

  First, encoding processing executed by the encoding unit 45 of the encoding device 33 will be described with reference to the flowchart of FIG.

  When the encoding process is started, the blocking unit 61 of the encoding processing unit 45 first acquires the digital image signal Vdg1 in step S1, and each frame image data included in the acquired digital image signal Vdg1. The block is divided into blocks of a predetermined size, supplied to the VQ unit 62, and the process proceeds to step S2.

  Next, in step S2, the VQ unit 62 extracts the pixels (specific pixels) at the four corners of each block using the supplied block-unit image data, and executes a vector quantization process to obtain each block. Vector quantization is applied to each group composed of the four corner pixels (specific pixels). Details of the vector quantization processing will be described later. When the vector quantization is performed, the VQ unit 62 supplies the obtained VQ code to the output unit 66 (FIG. 3) as selection code information Vcdvq, and also represents a representative value corresponding to the VQ code to the prediction unit 63 (FIG. 3). ) And the process proceeds to step S3.

  In step S <b> 3, the prediction unit 63 predicts pixel values of pixels other than the four corner pixels (specific pixels) in the block, and supplies the prediction result to the residual calculation unit 64. The prediction unit 63 supplies the representative value supplied from the VQ unit 62 to the residual calculation unit 64 as a prediction result when the pixel to be processed is a pixel at the four corners of the vector (specific pixel). When the prediction process ends, the prediction unit 63 advances the process to step S4.

  In step S4, the residual calculation unit 64 performs a residual calculation process, calculates a residual from the prediction pixel value supplied as a prediction result from the prediction unit 63 and the image data of the digital image signal Vdg1, and calculates the residual. This is supplied to the residual encoding unit 65. Details of the residual calculation process will be described later. When the residual calculation process ends, the residual calculation unit 64 advances the process to step S5.

  In step S5, the residual encoding unit 65 performs a residual encoding process, encodes the residual supplied from the residual calculation unit 64, and generates encoded data Vcddiff. Details of the residual encoding process will be described later. When the residual encoding unit 65 generates the encoded data Vcddiff, the residual encoding unit 65 supplies the encoded data Vcddiff to the output unit 66, and the process proceeds to step S6.

  In step S6, the output unit 66 outputs the encoded data Vcddiff supplied from the residual encoding unit 65 and the selection code information Vcdvq supplied from the VQ unit 62 as an encoded digital image signal Vcd1, and outputs it. The data is supplied to the recording unit 46 and the decoding unit 41. When the encoded digital image signal Vcd1 is output, the output unit 66 determines in step S7 whether or not to end the encoding process. For example, the processing for all the frames has not been completed, and the encoding process is ended. When it determines with not, the output part 66 returns a process to step S1, and repeats the process after it.

  If it is determined in step S7 that the process for all frames is completed or the encoding process is ended based on a user instruction or the like, the output unit 66 ends the encoding process.

  Next, details of the vector quantization processing executed in step S2 of FIG. 15 will be described with reference to the flowchart of FIG.

  When the vector quantization process is started, the specific pixel data extraction unit 81 extracts the pixel values of the four corner pixels of the supplied block and supplies them to the vector generation unit 82 in step S21. In step S22, the vector generation unit 82 groups the extracted specific pixels for each predetermined range according to the position, generates a vector for each group, and advances the process to step S23.

  In step S23, the code book 83 for each pixel pattern selects the type of code book to be used based on the pixel pattern of the processing target group that is the group in which the vector is generated by the vector generation unit 82, and the process proceeds to step S24. Proceed. In step S24, the VQ code determination unit 84 determines a VQ code corresponding to the vector based on the code book. At this time, the VQ code determination unit 84 determines a representative value corresponding to the VQ code.

  The VQ code determination unit 84 determines whether or not to end the vector quantization process. If it is determined that there is an unprocessed group and does not end, the process returns to step S23 and the subsequent processes are repeated. If it is determined in step S25 that the process is completed for all groups in all frames and the vector quantization process is ended, the VQ code determination unit 84 ends the vector quantization process and performs the process in step S2 of FIG. Is returned, and the subsequent processing is executed.

  Next, details of the residual calculation process executed in step S4 of FIG. 15 will be described with reference to the flowchart of FIG.

  When the image data and the predicted pixel value of the digital image signal Vdg1 are acquired, the pixel determination unit 111 confirms the position of the processing target pixel (target pixel) for calculating the residual in step S41. In step S42, the pixel determination unit 111 determines whether the target pixel is a pixel (specific pixel) at four corners of the block.

  If it is determined that the pixel is not a pixel at the four corners of the block, the pixel determination unit 111 advances the process to step S43. In step S43, the difference value calculation unit 112 calculates the difference value between the pixel value and the predicted pixel value in the image data, and the process proceeds to step S45.

  If it is determined in step S42 that the pixel is at the four corners of the block, the pixel determination unit 111 advances the process to step S44. In step S44, the difference value setting unit 113 sets the difference value to “0” (set to a predetermined value), and the process proceeds to step S45.

  In step S45, the residual output unit 114 outputs the difference value obtained by the process of step S43 or the process of step S44 as a residual, and supplies the residual value to the residual encoding unit 65. In step S <b> 46, the residual output unit 114 determines whether or not to end the residual calculation process, and determines that the residual is not calculated for all pixels in all frames and does not end the residual calculation process. If so, the process returns to step S41, and the subsequent processes are repeated. If it is determined in step S46 that the residual calculation process is to be terminated, the residual calculation process is terminated, the process returns to step S4 in FIG. 15, and the subsequent processes are executed.

  Next, details of the residual encoding process executed in step S5 of FIG. 15 will be described with reference to the flowchart of FIG.

  When the residual encoding process is started, the DST conversion unit 121 performs DST conversion processing on the residual supplied from the residual calculation unit 64 in step S61, and advances the process to step S62. In step S62, the quantization unit 122 performs a quantization process on the DST-transformed coefficient data, and the process proceeds to step S63. In step S <b> 63, the Huffman encoding unit 123 performs Huffman encoding processing on the quantized coefficient data obtained by the quantization, generates encoded data Vcddiff, and supplies it to the output unit 66.

  In step S64, the Huffman encoding unit 123 determines whether or not to end the residual encoding process, and when it is determined that there is residual data that has not been encoded and the residual encoding process is not to be ended. The Huffman encoding unit 123 returns the process to step S61 and repeats the subsequent processes. If it is determined in step S64 that all the residual data have been encoded and the residual encoding process is to be ended, the Huffman encoding unit 123 ends the residual encoding process, and steps in FIG. The processing is returned to S5, and the subsequent processing is executed.

  As described above, the encoding unit 45 actively uses analog distortion such as white noise and phase shift generated in the analog signal, and performs encoding processing so that large analog distortion intentionally occurs in the image signal. Each time the encoding process and the decoding process are repeated, the image can be greatly degraded.

  For example, in the image processing system 30 of FIG. 2, assuming that the analog image signal Van 1 is distorted due to the signal phase being shifted during D / A conversion by the D / A 42, the analog image signal Van 1 is subjected to A / D conversion by the A / D 44. Due to the sampling phase fluctuation, the block position of each block obtained by blocking by the encoding unit 45 is shifted from the block position in the first encoding and decoding (the block position is different every time). ).

  For this reason, in the encoding unit 45, the pixels encoded by the VQ unit 62 for the first time are different each time (specific pixels change every time). Furthermore, since these specific pixels are Huffman-encoded one or more times, they are different from the nature of the code book (pixel pattern-specific code book 83) used in the encoding of the VQ unit 62. Therefore, the influence of the quantization error is greater than when encoding for the first time (when encoding a pixel that has not been encoded).

  In addition, the encoding unit 45 performs prediction using the pixel value (representative value obtained by vector quantization) of the specific pixel encoded by the VQ unit 62 in the prediction unit 63. Further, the encoding unit 45 calculates a residual between the predicted pixel value and the pixel value in the digital image signal in the residual calculation unit 64, but the first code is added to the digital image signal due to a phase shift. Pixels that have become specific pixels due to conversion and pixels that are not are mixed, and a high frequency component is generated in the residual. Therefore, when the residual encoding unit 65 encodes the residual, a large distortion is caused.

  As described above, the digital image signal Vdg2 obtained by decoding the image signal Vcd1 obtained by decoding the digital image signal Vdg1 including analog distortion in the encoding unit 45 (the digital image output by the decoding unit 41 of the encoding device 33). The signal Vdg2) is greatly deteriorated compared to the digital image signal Vdg0 obtained from the decoding unit 41 of the reproducing device 31.

  That is, for example, when the reproduction device 31 reproduces the encoded digital image signal Vcd1 read from the recording unit 46 (the analog image signal Van1 output from the reproduction device 31 is encoded and decoded for the second time or later). The image data encoded by the encoding unit 45 as described above and further decoded by the decoding unit 41 (the image of the analog image signal Van2 D / A converted by the D / A 42) Data) has undergone the third and subsequent encoding processing and decoding processing, and the image quality is further deteriorated.

  As described above, the image quality obtained by reproducing the encoded digital image signal Vcd1 recorded on the recording medium by the recording unit 46 is significantly higher than the image by the analog image signal Van1 output from the reproduction device 31. It becomes deteriorated. Therefore, the encoding device 33 cannot replicate the analog image signal output from the reproduction device 31 while maintaining the good image quality of the image.

  Note that, for example, a noise component is generated in an analog image signal by repeating the encoding process and the decoding process with a conventional method, and simultaneously repeating the A / D conversion process and the D / A conversion process, so that the image quality gradually increases. However, this is merely the accumulation of noise components, which is different from the encoding processing and decoding processing by the image processing system 30 to which the present invention is applied.

  In other words, image quality degradation when the noise component is simply accumulated usually does not cause the image to break down if the S / N ratio is sufficiently low (the picture content cannot be understood). Further, it is easy to remove the noise component (improve image quality). On the other hand, in the encoding process of the present invention, as described above, analog distortion is used to generate a large distortion and corrupt the image (the image quality is greatly degraded). It is possible to obtain an effect different from “simply increasing the amount of noise and increasing the S / N ratio”.

  In addition, since the image quality is greatly deteriorated in the encoding process in this way, the image of the image signal before duplication is displayed normally without failure as in the case where the display device 32 displays an image on the display 43, for example. Is done.

  That is, the encoding unit 45 can prevent only a good quality copy of the analog signal without requiring a special process such as a scramble process or embedding noise information. As a result, the encoding device 33 can suppress illegal copying using an analog signal without causing inconveniences such as an image not being displayed and an increase in circuit scale.

  If there is no analog distortion (for example, when the digital image signal Vdg0 output from the decoding unit 41 is directly encoded), there is no phase shift in the signal, so that the VQ unit 62 performs the first encoding process. The encoded pixel (specific pixel) is also encoded in the second encoding process (a pixel that is a specific pixel in the first encoding process is also a specific pixel in the second encoding process). ) Since the encoded pixel value (code) of this pixel is also used in the decoding process, the same result as the first time can be obtained regardless of the number of times of vector quantization. Accordingly, the result of the subsequent processing is also substantially the same as the first time, and the encoding unit 45 can obtain substantially the same encoded data regardless of the number of times of the encoding processing. In other words, the decoding unit 41 decodes substantially the same encoded data regardless of the number of decoding processes, and can be reproduced with normal quality.

  Next, an example of the flow of decoding processing by the decoding unit 41 (FIG. 2) will be described with reference to the flowchart of FIG.

  When the decoding process is started, first, in step S81, the data decomposing unit 151 (FIG. 12) acquires the encoded digital image signal Vcd, and extracts the encoded data and selection code information included in the signal. , Separate into each.

  In step S82, the inverse VQ unit 152 performs inverse vector quantization processing using the separated selection code information, and calculates pixel values (pixel values of specific pixels) at the four corners of the block (that is, selection code). The representative value corresponding to the code of the information Vcdvq is determined). In step S83, the prediction unit 153 predicts the value of each pixel in the block using pixel values (representative values) at the four corners of the block.

  In step S84, the residual decoding unit 154 performs a residual decoding process on the encoded data separated by the data decomposing unit 151 and decodes it. Details of the residual decoding process will be described later. When the residual decoding process ends, the residual decoding unit 154 advances the process to step S85.

  In step S85, the pixel value adding unit 155 performs an addition calculation process of the predicted pixel value obtained by the process of step S83 and the residual obtained by the residual decoding process of step S84. Details of the addition calculation processing will be described later. When the addition operation process ends, the pixel value adding unit 155 advances the process to step S86.

  In step S86, the block decomposing unit 156 outputs the addition result obtained by the addition calculation process in step S85 as the digital image signal Vdg. In step S87, the block decomposing unit 156 determines whether or not to end the decoding process. For example, when it is determined that there is image data that has not been decoded yet and the decoding process is not ended, the block decomposing unit 156 The process returns to step S81, and the subsequent processes are repeated. For example, when it is determined in step S87 that all image data is decoded and the decoding process is finished, the block decomposing unit 156 ends the decoding process.

  Next, details of the residual decoding process executed in step S84 of FIG. 19 will be described with reference to the flowchart of FIG.

  When the residual decoding process is started, first, in step S101, the Huffman decoding unit 161 of the residual decoding unit 154 performs Huffman decoding processing on the encoded data Vcddiff to obtain quantized coefficient data. In step S102, the inverse quantization unit 162 performs inverse quantization processing on the quantized coefficient data obtained by the processing in step S101 to obtain DST coefficient data. In step S103, the IDST conversion unit 163 performs an IDST conversion process on the coefficient data obtained by the process of step S102, and obtains a decoded residual. In step S104, the IDST conversion unit 163 determines whether or not to end the residual decoding process, has not yet performed the residual decoding process on all the encoded data Vcddiff, and does not end the residual decoding process. If it is determined, the process returns to step S101, and the subsequent processes are repeated.

  If it is determined in step S104 that the processing for all the encoded data Vcddiff is completed and the residual decoding process is to be ended, the IDST conversion unit 163 ends the residual decoding process, and the process proceeds to step S84 in FIG. Return to, and execute the subsequent processing.

  Next, details of the addition calculation processing executed in step S85 in FIG. 19 will be described with reference to the flowchart in FIG.

  In step S121, the pixel determination unit 177 of the pixel value addition unit 155 acquires the predicted pixel value and the residual, and confirms the position of the target pixel on which the addition process is performed. In step S122, the pixel determination unit 177 determines whether or not the processing target pixel is a pixel at the four corners (specific pixel) of the block, and determines that the pixel is a pixel at the four corners (specific pixel) of the block. If so, the process proceeds to step S123.

  In step S123, the residual setting unit 172 sets the residual to “0”, and the process proceeds to step S124. If it is determined in step S122 that the processing target pixel is not a pixel at the four corners of the block (specific pixel), the pixel determination unit 171 advances the process to step S124.

  In step S124, the addition value calculator 173 adds the acquired predicted pixel value and the residual. The order aligning unit 174 holds the addition result, determines whether or not to end the addition calculation process in step S125, and determines that there is an unprocessed predicted pixel value or residual and does not end the addition calculation process. If so, the process returns to step S121 to repeat the subsequent processes. If it is determined in step S125 that the addition operation processing is to be terminated, the order arranging unit 174 proceeds to step S126, rearranges the addition results, ends the addition operation processing, and proceeds to step S85 in FIG. Return and execute the subsequent processing.

  As described above, the decoding unit 41 decodes the encoded data by the decoding method corresponding to the encoding process of the encoding unit 45. In this way, the decoding unit 41 causes the encoding unit 45 to generate a large analog distortion intentionally added by actively using analog distortion such as white noise and phase shift generated in the analog signal. Since the decoding process is performed so as to remain, the image can be greatly degraded every time the encoding process or the decoding process is repeated.

  That is, the decoding unit 41 can prevent only a good quality copy of the analog signal without requiring a special process such as a scramble process or embedding noise information. As a result, the playback device 31 can suppress illegal copying using an analog signal and safely output the analog signal without causing inconvenience such as no image being displayed or an increase in circuit scale. it can.

  That is, in the image processing system 30, the encoding device 33 cannot copy the analog image signal output from the reproducing device 31 so as not to deteriorate the image quality of the image. Accordingly, the image processing system 30 can suppress illegal copying using an analog signal and safely output the analog signal without causing inconveniences such as an increase in circuit scale and cost. Further, for example, when copying using a digital signal, such as copying in editing work, the image processing system 30 can perform copying without degrading image quality. In this case, D / A 42 and A / D 44 are omitted from the image processing system 30. Also, in this case, copyright management can be performed by using other technologies such as DRM (Digital Rights Management) together, so that the image processing system 30 can also prevent unauthorized duplication of digital signals. it can.

  In the above description, the DST conversion process has been described as the residual encoding method. However, the present invention is not limited to this. For example, the function approximation code that approximates the residual waveform with a function and transmits the coefficient is used. It is also possible to use a conversion.

  FIG. 22 is a block diagram showing a detailed configuration example of the residual encoding unit 65 (FIG. 3) in that case, and corresponds to FIG.

  In FIG. 22, the residual encoding unit 65 has a function approximation conversion unit 191 instead of the DST conversion unit 121 (FIG. 9). Further, the residual encoding unit 65 of FIG. 22 also includes a quantization unit 122 and a Huffman encoding unit 123, as in the case of FIG.

  As shown in FIG. 23, the function approximation conversion unit 191 approximates the waveform composed of each pixel value to, for example, a three-dimensional function with respect to the residual for each block, as shown in FIG. Is represented by

  For example, in the case of FIG. 23, the function approximation conversion unit 191 coordinates the position of each pixel with the pixel at the lower left of the block as the reference point, the horizontal direction as the x axis, and the vertical direction as the y axis (in the case of FIG. 23). 0 ≦ x ≦ 7, 0 ≦ y ≦ 7). Next, the function approximation conversion unit 191 converts the waveform composed of the pixel values of each pixel into a function using an approximation function. For example, the function approximation conversion unit 191 approximates a three-dimensional function represented by the following formula (5) to the waveform of the pixel value using, for example, a least square method.

  Since the residual values at the four corners of the block are set to “0” by the residual calculation unit 64, the following equation (6) is added to equation (5).

  Z (0,0) = Z (0,7) = Z (7,0) = Z (7,7) = 0 (6)

  The function approximation conversion unit 191 calculates coefficients a to i when the function of Expression (5) is approximated to the waveform of the pixel value by performing a least square method, and the coefficients a to i are used as coefficient data. This is supplied to the quantization unit 122.

  The quantization unit 122 quantizes the supplied coefficient data as in the case of FIG. Similarly to the case of FIG. 9, the Huffman encoding unit 123 also encodes the quantized coefficient data obtained in the quantizing unit 122 to generate encoded data.

  In this case, the residual decoding unit 154 (FIG. 12) of the decoding unit 41 (FIG. 2) performs the decoding process by a method corresponding to the function approximate conversion process.

  FIG. 24 is a block diagram illustrating a detailed configuration example of the residual decoding unit 154 in that case, and corresponds to FIG.

  24, the residual decoding unit 154 includes a Huffman decoding unit 161 and an inverse quantization unit 162 as in FIG. 13, and an inverse function approximation conversion unit 192 is used instead of the IDST conversion unit 163 in FIG. Have.

  The inverse function approximation conversion unit 192 generates an approximate function using the coefficient data obtained by the inverse quantization process by the inverse quantization unit 162 (substituting the coefficient data into the equation (5)), and from the approximate function The pixel value with each pixel is calculated. That is, the inverse function approximate conversion unit 192 calculates each pixel value (residual) by substituting the x coordinate and the y coordinate for the variables X and Y of the approximate function (formula (5)), respectively.

  The flow of the residual encoding process using the function approximation transformation as described above will be described with reference to the flowchart of FIG. This flowchart corresponds to the flowchart of FIG.

  That is, when the residual encoding process is started, the function approximation conversion unit 191 performs the function approximation conversion process on the supplied residual in step S141, and is configured by the residual of each pixel for each block. The generated waveform is converted into a function, and coefficient data of an approximate function is generated. In step S142, the quantization unit 122 performs a quantization process on the coefficient data in the same manner as in step S62 in FIG. 18, and generates quantized coefficient data. In step S143, the Huffman encoding unit 123 performs Huffman encoding processing on the quantized coefficient data in the same manner as in step S63 in FIG. 18, and generates encoded data Vcddiff.

  In step S144, the Huffman encoding unit 123 determines whether or not to end the residual encoding process, and determines that there is an unprocessed residual and does not end the residual encoding process. Returning to step 141, the subsequent processing is repeated. If it is determined in step S144 that the residual encoding process is to be ended, the Huffman encoding unit 123 ends the residual encoding process, returns the process to step S5 in FIG. 15, and executes the subsequent processes. Let

  By performing the function approximation conversion process in this way, the encoding unit 45 may cause the quality of information to deteriorate only when duplication is performed using an analog signal, as in the case of performing the DST conversion process. it can. Accordingly, in this case, the encoding device 33 does not cause inconveniences such as an increase in circuit scale, and the image data is significantly deteriorated in the second and subsequent encoding processes and the analog signal is used. Unauthorized copying can be suppressed.

  Next, with reference to the flowchart of FIG. 26, the decoding process corresponding to the encoding process described with reference to the flowchart of FIG. 25, that is, the flow of the decoding process using the function approximate conversion process will be described. The flowchart of FIG. 26 corresponds to the flowchart of FIG.

  When the residual decoding process is started, in step S161, the Huffman decoding unit 161 performs the Huffman decoding process on the encoded data Vcddiff in the same manner as in step S101 in FIG. 20, and generates quantized coefficient data. In step S162, the inverse quantization unit 162 performs inverse quantization processing on the quantized coefficient data, similarly to step S102 in FIG. 20, and generates coefficient data. In step S163, the inverse function approximate conversion unit 192 performs an inverse function conversion process, and calculates the original pixel value (residual) from the coefficient data.

  In step S164, the inverse function approximation conversion unit 192 determines whether or not to end the residual decoding process. For example, if it is determined that there is unprocessed encoded data and the residual decoding process is not ended, the process Is returned to step S161, and the subsequent processing is repeated. If it is determined in step S164 that the residual decoding process is to be terminated, the inverse function approximation conversion unit 192 ends the residual decoding process, returns the process to step S84 in FIG. 19, and performs the subsequent processes. Let it run.

  As described above, the inverse function approximate conversion process is performed in response to the function approximate conversion process of the encoding unit 45, so that the decoding unit 41 performs the duplication using an analog signal, similarly to the case of performing the IDST conversion process. Only the quality of information can be degraded. Accordingly, in this case, the reproducing device 31 also does not cause inconveniences such as an increase in circuit scale, and the image data is significantly deteriorated in the second and subsequent encoding processing and decoding processing. Copying can be suppressed.

  That is, even when the function approximation conversion process is performed in the encoding unit 45 and the inverse function approximation conversion process is performed in the decoding unit 41, the image processing system 30 does not cause inconveniences such as an increase in circuit scale and cost. Therefore, illegal copying using analog signals can be suppressed, and analog signals can be output safely. Further, for example, when copying using a digital signal, such as copying in editing work, the image processing system 30 can perform copying without degrading image quality. Further, for example, by using another technique such as DRM together, the image processing system 30 can also suppress unauthorized duplication of digital signals.

  The configuration of each device of the image processing system 30 may be other than that shown in FIG. 2, for example, as shown in FIG. 27, the decoding unit 41, the D / A 42, and the display of the encoding device 33 43 may be omitted.

  FIG. 27 is a diagram showing another configuration example of the image processing system to which the present invention is applied, and corresponds to FIG. That is, the image processing system 210 in FIG. 27 corresponds to the image processing system 30 in FIG. 2, and includes an encoding device 213 instead of the encoding device 33 in the image processing system 30.

  The encoding device 213 is a device corresponding to the encoding device 33 in FIG. 2, and has a configuration in which the decoding unit 41, the D / A 42, and the display 43 are omitted from the configuration of the encoding device 33.

  That is, the encoding device 213 of the image processing system 210 obtains the analog image signal Van1 output from the reproduction device 31 and digitizes and encodes the encoded digital image, similarly to the encoding device 33 of FIG. The signal Vcd1 is only generated and recorded on the recording medium, and the encoded digital image signal is decoded again, and the analog image signal Van2 is generated and the image is displayed on the display, like the encoding device 33. I do not.

  The encoding device 33 in FIG. 2 has a configuration applied for convenience in order to describe a case where the encoded image signal is decoded again. In practice, it is sufficient if encoding can be performed, and such a configuration is necessary. Not really.

  In FIG. 2 (FIG. 27), the configuration of each device described as one device may be configured as a plurality of devices, or conversely, a plurality of devices may be configured as one device. Also good.

  FIG. 28 is a diagram showing still another configuration example of the image processing system to which the present invention is applied. An image processing system 220 in FIG. 28 corresponds to the image processing system 30 in FIG. In FIG. 28, the image processing system 220 includes two decoding devices 221, two display devices 222, an A / D conversion device 223, an encoding device 224, and a recording device 225.

  The decoding device 221 has a decoding unit 41, the display device 222 has a D / A 42 and a display 43, the A / D conversion device 223 has an A / D 44, and the encoding device 224 has an encoding unit 45. The recording device 225 has a recording unit 46.

  That is, the image processing system 220 is the same as the image processing system 30 in FIG. 2 except that the configuration of the apparatus is different. Therefore, in the image processing system 220, the same processing as that of the image processing system 30 is performed by each device. Therefore, similarly to the image processing system 30, unauthorized duplication of content data using an analog signal can be suppressed.

  Moreover, you may make it add the structure other than the structure mentioned above to the image processing system of FIG. For example, a noise component (analog distortion such as white noise or phase shift) may be positively added to the analog image signal Van so that the image quality is significantly deteriorated when the analog image signal is copied. However, this noise component is not simply added to improve the S / N ratio, but to further deteriorate the image quality in the encoding process or decoding process described above (to cause a large distortion in the image signal). It is added for active use.

  FIG. 29 is a diagram showing still another configuration example of the image processing system to which the present invention is applied, and corresponds to FIG. 2 and FIG.

  In FIG. 29, the image processing system 240 includes two playback devices 241, an encoding device 242, two display devices 32, and a recording device 225. As described with reference to FIG. 2, the display device 32 is a device that displays the image of the analog image signal Van <b> 1 or Van <b> 2 output from the reproduction device 241 on the display 43. As described with reference to FIG. 28, the recording device 225 includes the recording unit 46, and records the encoded digital image signal Vcd 1 output from the encoding device 242 on the recording medium of the recording unit 46.

  The playback device 241 includes a decoding unit 41 and a D / A 42 as with the playback device 31, and further includes an analog noise addition unit 251. The analog noise adding unit 251 adds a noise component (analog noise) to the analog image signal converted by the D / A 42.

  Here, the analog noise is a noise component added to the analog signal, and is a noise component with respect to the analog component. In other words, the analog noise is a noise component that generates analog distortion (analog component distortion) such as white noise and phase shift.

  That is, the playback device 241 outputs the analog image signal Van to which analog noise is positively added. For example, the playback device 241 generates an analog image signal Van1 to which analog noise is positively added from the encoded digital image signal Vcd0. Further, for example, the playback device 241 generates an analog image signal Van2 to which analog noise is positively added from the encoded digital image signal Vcd1.

  The encoding device 242 includes an A / D 44 and an encoding unit 45 as in the encoding device 33 of FIG. 2, and further includes an analog noise adding unit 251. That is, the encoding device 242 performs A / D conversion on the analog image signal to which analog noise is positively added in the analog noise adding unit 251 in the A / D 44 and encodes it in the encoding unit 45.

  In the image processing system 240 of FIG. 29, an analog deterioration encoding process performed by the encoding device 242 to add analog noise to an analog image signal for encoding will be described with reference to the flowchart of FIG. .

  First, in step S181, the analog noise adding unit 251 adds analog noise (white noise, phase shift, etc.) to the analog image signal Van output from the playback device 241. In step S182, the encoding device 242 performs A / D conversion processing on the analog image signal Van to which analog noise is positively output, which is output from the analog noise adding unit 251, and generates a digital image signal Vdg. To do. In step S183, the encoding unit 45 performs an encoding process. Since this encoding process is the same as the encoding process described with reference to the flowchart of FIG. 15, a detailed description thereof is omitted.

  When the encoding process ends, the encoding unit 45 advances the process to step S184, determines whether to end the analog deterioration encoding process, and returns to step S181 if it determines not to end the process. The subsequent processing is repeated. If it is determined in step S184 that the analog deterioration encoding process is to be ended, the analog deterioration encoding process is ended.

  Next, an analog deterioration decoding process for positively adding analog noise to the decoded analog image signal, which is executed by the playback device 241 in the image processing system 240 of FIG. 29, will be described with reference to the flowchart of FIG.

  First, in step S201, the decoding unit 41 performs a decoding process on the input encoded digital image signal. Since this decoding process is the same as the decoding process described with reference to the flowchart of FIG. 19, a detailed description thereof is omitted.

  When the decoding process is completed and the digital image signal Vdg is obtained, the D / A 42 performs a D / A conversion process on the digital image signal Vdg in step S202 to obtain an analog image signal Van. In step S203, the analog noise adding unit 251 adds analog noise (white noise, phase shift, etc.) to the analog image signal Van D / A converted in the D / A 42.

  When the analog noise is added, the analog noise adding unit 251 advances the process to step S204, determines whether to end the analog degradation decoding process, and returns to step S201 if it determines not to end, and thereafter Repeat the process. If it is determined in step S204 that the analog degradation decoding process is to be terminated, the analog degradation decoding process is terminated.

  Thus, the encoding device 242 positively adds analog noise to the analog image signal. Accordingly, when copying is performed using an analog signal in the image processing system 240, noise is positively added to the analog image signal by repeating the encoding process and the decoding process, and the image quality of the image is further improved. Since it deteriorates remarkably, the encoding device 242 can perform the encoding process so as to suppress unauthorized duplication of the content data using the analog signal.

  Similarly, the playback device 241 also actively adds analog noise to the analog image signal. Therefore, the playback device 241 can perform a decoding process so as to suppress unauthorized duplication of content data using an analog signal.

  That is, the image processing system 240 does not cause inconveniences such as an image not being displayed or an increase in the circuit scale, and the image data is deteriorated significantly in the second and subsequent encoding processes. It is possible to further suppress unauthorized copying using.

  The series of processes described above can be executed by hardware or can be executed by software. In this case, for example, the devices constituting the image processing system 30 in FIG. 2, the image processing system 210 in FIG. 27, the image processing system 220 in FIG. 28, and the image processing system 240 in FIG. 29 are shown in FIG. It may be configured as such a personal computer.

  In FIG. 32, a CPU (Central Processing Unit) 301 of the personal computer 300 performs various processes according to a program stored in a ROM (Read Only Memory) 302 or a program loaded from a storage unit 313 to a RAM (Random Access Memory) 303. Execute the process. The RAM 303 also appropriately stores data necessary for the CPU 301 to execute various processes.

  The CPU 301, ROM 302, and RAM 303 are connected to each other via a bus 304. An input / output interface 310 is also connected to the bus 304.

  The input / output interface 310 includes an input unit 311 including a keyboard and a mouse, a display including a CRT (Cathode Ray Tube) and an LCD (Liquid Crystal Display), an output unit 312 including a speaker, and a hard disk. A communication unit 314 including a storage unit 313 and a modem is connected. The communication unit 314 performs communication processing via a network including the Internet.

  A drive 315 is connected to the input / output interface 310 as necessary, and a removable medium 321 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory is appropriately mounted, and a computer program read from them is It is installed in the storage unit 313 as necessary.

  When the above-described series of processing is executed by software, a program constituting the software is installed from a network or a recording medium.

  For example, as shown in FIG. 32, the recording medium is distributed to distribute the program to the user separately from the apparatus main body, and includes a magnetic disk (including a flexible disk) on which the program is recorded, an optical disk ( Removable media 321 composed of CD-ROM (compact disk-read only memory), DVD (digital versatile disk), magneto-optical disk (including MD (mini-disk) (registered trademark)), or semiconductor memory In addition to being configured, it is configured by a ROM 302 on which a program is recorded, a hard disk included in the storage unit 313, and the like distributed to the user in a state of being incorporated in the apparatus main body in advance.

  In the present specification, the step of describing the program recorded on the recording medium is not limited to the processing performed in chronological order according to the described order, but is not necessarily performed in chronological order. It also includes processes that are executed individually.

  Further, in this specification, the system represents the entire apparatus composed of a plurality of devices (apparatuses).

It is a figure which shows the structural example of the conventional image processing system. It is a figure which shows the structural example of the image processing system to which this invention is applied. It is a block diagram which shows the example of an internal structure of the encoding part of FIG. It is a schematic diagram explaining the example of a mode that frame image data is made into a block. It is a block diagram which shows the structural example of the VQ part of FIG. It is a schematic diagram which shows the example of a specific pixel. It is a schematic diagram explaining the example of the mode of a prediction process. It is a block diagram which shows the structural example of the residual calculation part of FIG. It is a block diagram which shows the structural example of the residual encoding part of FIG. It is a schematic diagram explaining the example of the mode of a one-dimensional DST conversion process. It is a figure for demonstrating the mode of a two-dimensional DST conversion process. It is a block diagram which shows the structural example of the decoding part of FIG. It is a block diagram which shows the structural example of the residual decoding part of FIG. It is a block diagram which shows the structural example of the pixel value addition part of FIG. It is a flowchart explaining the example of an encoding process. It is a flowchart explaining the example of a vector quantization process. It is a flowchart explaining the example of a residual calculation process. It is a flowchart explaining the example of a residual encoding process. It is a flowchart explaining the example of a decoding process. It is a flowchart explaining the example of a residual decoding process. It is a flowchart explaining the example of an addition calculation process. It is a block diagram which shows the other structural example of the residual encoding part of FIG. It is a schematic diagram for demonstrating the mode of a function approximate conversion process. It is a block diagram which shows the other structural example of the residual decoding part of FIG. It is a flowchart explaining the other example of a residual encoding process. It is a flowchart explaining the other example of a residual decoding process. It is a figure which shows the other structural example of the image processing system to which this invention is applied. It is a figure which shows the further another structural example of the image processing system to which this invention is applied. It is a figure which shows the further another structural example of the image processing system to which this invention is applied. It is a flowchart explaining the example of an analog degradation encoding process. It is a flowchart explaining the example of an analog degradation decoding process. It is a figure which shows the structural example of the personal computer to which this invention is applied.

Explanation of symbols

  30 image processing system, 31 playback device, 33 encoding device, 41 decoding unit, 42 D / A, 44 A / D, 45 encoding unit, 61 blocking unit, 62 VQ unit, 63 prediction unit, 64 residual calculation , 65 residual encoding unit, 66 output unit, 81 specific pixel data extraction unit, 82 vector generation unit, 83 pixel pattern-specific code book, 84 VQ code determination unit, 111 pixel determination unit, 112 difference value calculation unit, 113 Difference value setting unit, 114 residual output unit, 121 DST conversion unit, 122 quantization unit, 123 Huffman coding unit, 151 data decomposition unit, 152 inverse VQ unit, 153 prediction unit, 154 residual decoding unit, 155 pixel value Adder, 156 Block decomposing unit, 161 Huffman decoding unit, 162 Inverse quantization unit, 163 IDST conversion unit, 171 Pixel determination unit, 172 residual setting unit, 173 addition value calculation unit, 174 order alignment unit, 191 function approximation conversion unit, 192 inverse function approximation conversion unit, 210 image processing system, 213 encoding device, 220 image processing system, 221 Decoding device, 224 encoding device, 240 image processing system, 241 playback device, 242 encoding device, 251 analog noise adding unit, 300 personal computer

Claims (24)

An encoding device that encodes input image data including analog distortion ,
Blocking means for dividing each frame image of the input image data into a plurality of blocks ,
Wherein the blocking means and the specific pixel a plurality of pixels of the peripheral portion of each block obtained by the block of, and a group specific pixel group adjacent to each other among all the pixel group not limited to the specific pixel, Vector quantization means for vector-quantizing the pixel value of the specific pixel for each group ;
Prediction means for predicting the pixel value of each pixel other than the specific pixel in the block on the basis of the pixel value of the specific pixel vector-quantized by the vector quantization means in each block ;
For each pixel other than the specific pixel in the block, a difference calculation unit that calculates a difference between a predicted pixel value that is a pixel value predicted by the prediction unit and a pixel value in the input image data;
Encoding apparatus Ru and a differential encoding means for encoding each said block the difference obtained by the difference calculation means. The vector quantization means sets the four corner pixels of each block as specific pixels .
Encoding apparatus according to 請 Motomeko 1. The prediction means predicts a pixel value of each pixel other than the specific pixel in the block using a pixel value of each specific pixel and a distance to each specific pixel.
The encoding device according to claim 1. The prediction means sets a pixel value of each pixel other than the specific pixel in the block to a pixel value of the specific pixel closest to the pixel.
Encoding apparatus according to 請 Motomeko 1. The difference calculation means further sets the difference of the specific pixel to “0”,
The difference encoding means encodes the difference of all pixels in the block including the specific pixel.
Encoding apparatus according to 請 Motomeko 1. The differential encoding means includes
Orthogonal transformation means for orthogonally transforming the difference obtained by the difference calculation means;
Quantization means for quantizing coefficient data obtained by orthogonally transforming the difference by the orthogonal transform means;
Encoding apparatus according to 請 Motomeko 1 and a variable-length coding means for variable length coding the quantized coefficient data to which the coefficient data is obtained are quantized by the quantization means. The orthogonal transform means performs discrete sine transform on the difference.
Encoding apparatus according to 請 Motomeko 6. Selection code information that is information related to a code corresponding to a vector quantization result of the group of specific pixels selected by the vector quantization means, and the difference is obtained by encoding the difference by the difference encoding means Output means for outputting encoded data to the outside of the encoding device is further provided.
Encoding apparatus according to 請 Motomeko 1. Noise adding means for adding analog noise, which is a noise component with respect to the analog component, to the input image data of the analog signal;
A / D converting the input image data of the analog signal to which analog noise has been added by the noise adding means, and A / D converting means for obtaining the input image data of digital data including the analog distortion, and
The blocking means divides each frame image of the input image data of the digital data obtained by A / D conversion by the A / D conversion means into a plurality of blocks and blocks them
Encoding apparatus according to 請 Motomeko 1. An encoding method of an encoding device for encoding input image data including analog distortion ,
Blocking means of the encoding device, and blocks by dividing each frame image of the input image data into a plurality of blocks,
Specific pixels adjacent to each other in all pixel groups that are not limited to the specific pixels, with a plurality of pixels at the peripheral edge of each block obtained by the vector quantization means of the encoding device being made into blocks as specific pixels the group as a group, the pixel value of the specific pixel and vector quantization for each of the groups,
Prediction means of the encoding device, in each block, based on the pixel value of the specific pixel that is vector quantized, to predict the pixel values of the pixels other than the specific pixel in the block,
It said difference calculating means of the encoding device, for each pixel other than the specific pixel in the block, calculates a difference between the predicted pixel value of the input image data and the prediction pixel value is a pixel value,
The differential encoding means of the encoding device encodes the obtained difference for each block.
It marks Goka way. A computer that encodes input image data including analog distortion ,
Blocking means for dividing each frame image of the input image data into a plurality of blocks,
A plurality of pixels at the peripheral edge of each block obtained by blocking by the blocking unit is a specific pixel, a group of specific pixels adjacent to each other among all pixel groups not limited to the specific pixel, and the group Vector quantization means for vector-quantizing the pixel value of the specific pixel every time;
Prediction means for predicting the pixel value of each pixel other than the specific pixel in the block on the basis of the pixel value of the specific pixel vector-quantized by the vector quantization means in each block;
For each pixel other than the specific pixel in the block, a difference calculation unit that calculates a difference between a predicted pixel value that is a pixel value predicted by the prediction unit and a pixel value in the input image data;
Difference encoding means for encoding the difference obtained by the difference calculation means for each block
A computer-readable recording medium in which a program for functioning as a computer is recorded. A computer that encodes input image data including analog distortion ,
Blocking means for dividing each frame image of the input image data into a plurality of blocks,
A plurality of pixels at the peripheral edge of each block obtained by blocking by the blocking unit is a specific pixel, a group of specific pixels adjacent to each other among all pixel groups not limited to the specific pixel, and the group Vector quantization means for vector-quantizing the pixel value of the specific pixel every time;
Prediction means for predicting the pixel value of each pixel other than the specific pixel in the block on the basis of the pixel value of the specific pixel vector-quantized by the vector quantization means in each block;
For each pixel other than the specific pixel in the block, a difference calculation unit that calculates a difference between a predicted pixel value that is a pixel value predicted by the prediction unit and a pixel value in the input image data;
Difference encoding means for encoding the difference obtained by the difference calculation means for each block
Program to function as. A decoding device for decoding encoded data obtained by encoding image data including analog distortion by an encoding device,
A plurality of pixels at the peripheral edge of each block of each frame image of the image data are set as specific pixels, and among specific pixel groups not limited to the specific pixels, adjacent specific pixel groups are grouped, and for each group The pixel value of the specific pixel is vector-quantized, and the pixel value of each pixel other than the specific pixel in the block is predicted based on the pixel value of the specific pixel vector-quantized in each block. The difference between the predicted pixel value and the pixel value in the image data is calculated for each pixel other than the specific pixel, and the vector quantum of the specific pixel is calculated from the encoded data obtained by encoding the difference for each block. Separating means for separating selected code information, which is information relating to a code selected as a result of the conversion,
Inverse vector quantization means for inverse vector quantizing the selection code information separated from the encoded data by the separation means ;
Prediction said inverse vector using the pixel value of the specific pixel obtained is inverse vector quantized by the quantization means, of the probe in the lock, including the specific pixel, predicts the pixel value of each pixel other than the specific pixel Means,
Differential decoding means for decoding the encoded data from which the selection code information has been separated by the separation means;
Wherein for each pixel other than the specific pixel, the a predicted pixel value obtained by the prediction means, decrypt device and a pixel value adding means for adding the difference component obtained is decoded by the difference decoding means. The specific pixels are pixels at the four corners of each block.
Decoding apparatus according to 請 Motomeko 13. The pixel value adding means sets the difference of the specific pixel to “0” and performs addition.
Decoding apparatus according to 請 Motomeko 13. The pixel value adding means rearranges the pixel values of each pixel obtained as an addition result in raster order for each block.
Decoding apparatus according to 請 Motomeko 13. The differential decoding means includes
A variable length decoding means for variable-length decoding the previous SL encoded data,
Inverse quantization means for inversely quantizing quantized coefficient data obtained by variable length decoding the encoded data by the variable length decoding means;
Decoding apparatus according to 請 Motomeko 13 and a inverse orthogonal transform means for inverse orthogonal transform coefficient data obtained the quantized coefficient data by the inverse quantization means is inverse quantized. The orthogonal transform means performs inverse discrete sine transform on the coefficient data.
Decoding apparatus according to 請 Motomeko 17. D / A conversion of digital image data composed of the pixel values obtained in the pixel value addition means, and converts it into an analog signal; and
Noise adding means for adding analog noise, which is a noise component with respect to an analog component, to the analog signal obtained by D / A converting the digital image data by the D / A converting means;
Decoding apparatus according to further comprising Ru claim 13 and an output means for outputting the analog signal which the analog noise has been added by the noise adding means. A decoding method of a decoding apparatus for decoding encoded data obtained by encoding image data including analog distortion by an encoding apparatus,
The separation unit of the decoding device is configured such that a plurality of pixels at a peripheral portion of each block of each frame image of the image data are specific pixels, and specific pixel groups adjacent to each other are not limited to the specific pixels. A pixel value of each pixel other than the specific pixel in the block based on the pixel value of the specific pixel that is group-quantized, and the pixel value of the specific pixel is vector-quantized for each group The encoded data in which the value is predicted, the difference between the predicted pixel value and the pixel value in the image data is calculated for each pixel other than the specific pixel in the block, and the difference is encoded for each block From the selected code information, which is information about the code selected as a result of vector quantization of the specific pixel,
Inverse vector quantization means of the decoding device performs inverse vector quantization on the selection code information separated from the encoded data,
The prediction unit of the decoding device predicts the pixel value of each pixel other than the specific pixel in the block including the specific pixel, using the pixel value of the specific pixel obtained by inverse vector quantization,
The differential decoding means of the decoding device decodes the encoded data from which the selection code information is separated,
The pixel value adding means of the decoding device adds the obtained predicted pixel value and the difference obtained by decoding for each pixel other than the specific pixel.
Decrypt method. A computer that decodes encoded data obtained by encoding image data including analog distortion by an encoding device;
A plurality of pixels at the peripheral edge of each block of each frame image of the image data are set as specific pixels, and among specific pixel groups not limited to the specific pixels, adjacent specific pixel groups are grouped, and for each group The pixel value of the specific pixel is vector-quantized, and the pixel value of each pixel other than the specific pixel in the block is predicted based on the pixel value of the specific pixel vector-quantized in each block. The difference between the predicted pixel value and the pixel value in the image data is calculated for each pixel other than the specific pixel, and the vector quantum of the specific pixel is calculated from the encoded data obtained by encoding the difference for each block. Separating means for separating selected code information, which is information relating to a code selected as a result of the conversion,
Inverse vector quantization means for inverse vector quantizing the selection code information separated from the encoded data by the separation means;
Prediction means for predicting the pixel value of each pixel other than the specific pixel in the block including the specific pixel, using the pixel value of the specific pixel obtained by inverse vector quantization by the inverse vector quantization means When,
Differential decoding means for decoding the encoded data from which the selection code information has been separated by the separation means;
Pixel value addition means for adding the prediction pixel value obtained by the prediction means and the difference obtained by decoding by the difference decoding means for each pixel other than the specific pixel
A computer-readable recording medium in which a program for functioning as a computer is recorded. A computer that decodes encoded data obtained by encoding image data including analog distortion by an encoding device;
A plurality of pixels at the peripheral edge of each block of each frame image of the image data are set as specific pixels, and among specific pixel groups not limited to the specific pixels, adjacent specific pixel groups are grouped, and for each group The pixel value of the specific pixel is vector-quantized, and the pixel value of each pixel other than the specific pixel in the block is predicted based on the pixel value of the specific pixel vector-quantized in each block. The difference between the predicted pixel value and the pixel value in the image data is calculated for each pixel other than the specific pixel, and the vector quantum of the specific pixel is calculated from the encoded data obtained by encoding the difference for each block. Separating means for separating selected code information, which is information relating to a code selected as a result of the conversion,
Inverse vector quantization means for inverse vector quantizing the selection code information separated from the encoded data by the separation means;
Prediction means for predicting the pixel value of each pixel other than the specific pixel in the block including the specific pixel, using the pixel value of the specific pixel obtained by inverse vector quantization by the inverse vector quantization means When,
Differential decoding means for decoding the encoded data from which the selection code information has been separated by the separation means;
Pixel value addition means for adding the prediction pixel value obtained by the prediction means and the difference obtained by decoding by the difference decoding means for each pixel other than the specific pixel
Program to function as. In an information processing system that includes an encoding unit and a decoding unit, and the image data deteriorates when the encoding process and the decoding process are repeated for image data including analog distortion ,
The encoding unit includes:
Blocking means for dividing each frame image of the image data into a plurality of blocks,
A plurality of pixels at the peripheral edge of each block obtained by blocking by the blocking unit is a specific pixel, a group of specific pixels adjacent to each other among all pixel groups not limited to the specific pixel, and the group Vector quantization means for vector-quantizing the pixel value of the specific pixel every time;
Prediction means for predicting the pixel value of each pixel other than the specific pixel in the block on the basis of the pixel value of the specific pixel vector-quantized by the vector quantization means in each block;
For each pixel other than the specific pixel in the block, a difference calculation unit that calculates a difference between a predicted pixel value that is a pixel value predicted by the prediction unit and a pixel value in the image data;
Information processing system comprising a differential encoding means for encoding the difference obtained by the difference calculation means for each of said blocks. In an information processing system that includes an encoding unit and a decoding unit, and the image data deteriorates when the encoding process and the decoding process are repeated for image data including analog distortion ,
The decoding unit
A plurality of pixels at the peripheral edge of each block of each frame image of the image data are set as specific pixels, and among specific pixel groups not limited to the specific pixels, adjacent specific pixel groups are grouped, and for each group The pixel value of the specific pixel is vector-quantized, and the pixel value of each pixel other than the specific pixel in the block is predicted based on the pixel value of the specific pixel vector-quantized in each block. The difference between the predicted pixel value and the pixel value in the image data is calculated for each pixel other than the specific pixel, and the vector quantum of the specific pixel is calculated from the encoded data obtained by encoding the difference for each block. Separating means for separating selected code information, which is information relating to a code selected as a result of the conversion,
Inverse vector quantization means for inverse vector quantizing the selection code information separated from the encoded data by the separation means;
Prediction means for predicting the pixel value of each pixel other than the specific pixel in the block including the specific pixel, using the pixel value of the specific pixel obtained by inverse vector quantization by the inverse vector quantization means When,
Differential decoding means for decoding the encoded data from which the selection code information has been separated by the separation means;
Wherein for each pixel other than the specific pixel, information processing system comprising a predicted pixel value obtained by the prediction means, a pixel value adding means for adding the difference obtained by being decoded by the difference decoding means.

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