JP4556694B2 - Encoding apparatus and method, recording medium, program, and image processing system - Google Patents

Description

The present invention is an encoding apparatus and method, recording medium, program, and an image processing system, in particular, suitable coding apparatus and method used in the case to prevent a copy of the analog data, recording medium, program, and an image related to the processing system.

  A general recording medium (for example, a cassette magnetic tape such as a DVD (Digital Versatile Disc) or VHS (Video Home System)) on which an image signal such as video content is recorded is reproduced by a reproduction device, and the reproduction result is analog data. Assuming that the data is supplied to a television receiver, the analog data supplied to the television receiver is branched and input to a predetermined recording device to create a copy of the video content. can do.

  However, since such a copy creation may infringe copyright, a method for preventing unauthorized copying of video content or the like has been proposed.

  Specifically, methods have been proposed in which scramble processing is performed on analog data output from the playback device, or output of analog data is prohibited (see, for example, Patent Document 1).

  According to the conventional method described above, illegal copying of analog data can be suppressed. However, there is a problem that a normal image cannot be displayed on a television receiver or the like to which the analog data is supplied.

Therefore, in order to solve the above-described problems, the present applicant performs encoding by paying attention to analog noise such as a phase shift when encoding analog data into digital data, thereby decoding the image quality after decoding. An invention for degrading the above has already been filed (for example, see Patent Document 2).
JP 2001-245270 A Japanese Patent Application Laid-Open No. 2004-289685

  According to the invention described in Patent Document 1, unauthorized copying of analog data can be suppressed. Further, according to the invention described in Patent Document 2, a normal image can be displayed on a television receiver or the like to which the analog data is supplied.

  However, the search for an invention that suppresses unauthorized copying of analog data is not limited to Patent Document 2, and a solution by the further invention of the above-described problem is demanded.

  The present invention has been made in view of such a situation, when analog data is digitized and encoded, and when a series of processes for decoding the resulting digitally encoded data is repeated, similar encoding, It is ensured that the second and subsequent decoding results are degraded in spite of decoding. As a result, copying of analog data can be suppressed.

Encoding apparatus of the present invention subdivides the image data and the block dividing means for dividing the basic blocks of a predetermined uniform size, each basic block is split into smaller uniform size of the divided blocks, the divided blocks Based on the feature quantity detection means that detects the activity indicating the variation in the pixel values of the pixels constituting the divided block and the activity detected for each divided block of the basic block For each block, the size of the divided block with the largest variation in pixel values among multiple divided blocks is reduced, and the size of other divided blocks is changed accordingly. and re-blocking means for re-blocked into blocks, subdivision of the basic block has been re-blocked Including an encoding means for encoding image data for each lock.

  Noise can be added to the image data.

The encoding apparatus of the present invention can further include noise adding means for adding noise to the input image data and outputting the added image data to the block dividing means .

  The image data may be decoded after being encoded at least once.

Encoding means applies the ADRC, the image data for each subdivision blocks basic block has been re-blocked may be adapted to encode.

The encoding means includes a code obtained as a result of encoding image data for each subdivision block in which the basic block has been reblocked , and encoded data including at least the size of the non-uniform subdivision block that has been reblocked Can be output.

The encoding apparatus of the present invention can further include a decoding unit that decodes encoded data output from the encoding unit.

Coding method of the present invention subdivides the image data and the block dividing step of dividing into basic blocks of a predetermined uniform size, each basic block is split into smaller uniform size of the divided blocks, the divided blocks Based on the feature amount detection step that detects the activity indicating the variation of the pixel values of the pixels constituting the divided block and the activity detected for each divided block of the basic block as the feature amount indicating the feature of the image data For each block, the size of the divided block with the largest variation in pixel values among multiple divided blocks is reduced, and the size of other divided blocks is changed accordingly. and re-blocking step of re-blocked into blocks, basic blocks reblocked Including an encoding step of encoding the image data for each subdivision blocks.

The recording medium of the present invention includes a block dividing step for dividing image data into basic blocks of a predetermined uniform size, and subdividing each divided basic block into smaller uniform size divided blocks, and image data in the divided blocks For each basic block, a feature amount detecting step for detecting an activity indicating a variation in pixel values of pixels constituting a divided block and an activity detected for each divided block of the basic block are used as the feature amount indicating the feature of each basic block. In addition, by reducing the size of the divided block having the largest variation in pixel values among the plurality of divided blocks and changing the size of the other divided blocks accordingly, the basic block is changed to a non-uniform re-divided block. The reblock step to reblock and the basic block is reblocked Program for executing the image data for each re-divided block processing including an encoding step of encoding the computer of the encoding device is recorded with.

The program of the present invention includes a block dividing step for dividing image data into predetermined uniform size basic blocks, and subdividing each divided basic block into smaller uniform size divided blocks, and image data in the divided blocks is divided. For each basic block, based on the feature amount detection step for detecting the activity indicating the variation of the pixel value of the pixels constituting the divided block and the activity detected for each divided block of the basic block as the feature amount indicating the feature By reducing the size of the divided block having the largest pixel value variation among the plurality of divided blocks and changing the size of the other divided blocks accordingly, the basic block is re-divided into non-uniform re-divided blocks. Reblocking step to block and basic block reblocked The image data to execute processing including an encoding step of encoding the computer of the encoding device for each subdivision blocks.

In the encoding apparatus, encoding method, and program of the present invention, image data is divided into basic blocks of a predetermined uniform size, and each divided basic block is further subdivided into divided blocks of a uniform size. The activity indicating the variation of the pixel values of the pixels constituting the divided block is detected as the feature quantity indicating the feature of the image data in the divided block, and the basic block is determined based on the activity detected for each divided block of the basic block. Each time, the size of the divided block with the largest pixel value variation among the plurality of divided blocks is reduced, and the size of the other divided blocks is changed accordingly. Subdivided blocks that are reblocked and the basic block is reblocked Image data is encoded.

In the image processing system according to the present invention, the encoding unit subdivides the image data into basic blocks having a predetermined uniform size, and subdivides each divided basic block into smaller uniform size divided blocks. The feature amount detecting means for detecting the activity indicating the variation of the pixel values of the pixels constituting the divided block as the feature amount indicating the feature of the image data in the divided block, and the activity detected for each divided block of the basic block For each basic block, the size of the divided block having the largest variation in pixel values among the plurality of divided blocks is reduced, and the size of the other divided blocks is changed accordingly. Re-blocking means to re-block into uniform sub-division blocks and basic blocks to re-block Encoding means for encoding image data for each divided subdivision block, and the decoding unit divides the image data into predetermined subdivision blocks by the encoding unit and encodes the subdivision block unit. Analyzing means for analyzing the encoded data that is the result of the analysis, and decoding means for decoding the encoded data in units of subdivision blocks based on the analysis result by the analyzing means.

In the image processing system of the present invention, the encoding unit divides the image data into basic blocks of a predetermined uniform size, and each divided basic block is subdivided into smaller uniform size divided blocks. As a feature quantity indicating the feature of the image data in the block, an activity indicating a variation in pixel values of pixels constituting the divided block is detected, and for each basic block based on the activity detected for each divided block of the basic block. The size of the divided block having the largest pixel value variation among the plurality of divided blocks is reduced, and the size of the other divided blocks is changed accordingly, so that the basic block becomes a non-uniform re-divided block. An image for each subdivision block that has been reblocked and whose basic blocks have been reblocked Over data is encoded. Also, the decoding unit analyzes the encoded data that is the result of the image data being divided into predetermined subdivision blocks by the encoding unit and encoded in units of subdivision blocks, and based on the analysis result, the encoding data is encoded. Data is decoded in subdivided blocks.

  According to the present invention, when analog data is digitized and encoded, and a series of processes for decoding the resulting digitally encoded data is repeated, the second and subsequent times are performed regardless of similar encoding and decoding. Can be degraded. Therefore, copying of analog data can be suppressed.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

FIG. 1 shows a configuration example of an image display system to which the present invention is applied. The image display system 1 includes an encoding device 12 that encodes an analog image signal V _an0 input from a tuner 11 or the like and records the encoded image data on a recording medium 13, and encoded digital data V _{rd, 0} recorded on the recording medium 13. reproducing device 14 the reading and reproducing, codes to be recorded on the display 15, the playback apparatus 14 by encoding an analog image signal V _an1 supplied from the recording medium 17 to display an analog image signal V _an1 supplied from the reproducing apparatus 14 apparatus 16 consists of a display 18 for displaying an analog image signal V _an2 supplied from and marks Goka device 16.

The tuner 11 receives a television broadcast, for example, and outputs an analog image signal V _an0 obtained as a result to the encoding device 12.

The encoding device 12 digitizes the analog image signal V _an0 input from the tuner 11 and outputs the resulting digital image signal V _dg1,0 to the encoding unit 22-1 (A / D). ) 21, an encoding unit 22-1 that encodes the digital image signal V _dg1,0 and outputs the resulting encoded digital image data V _{cd, 0} to the recording unit 23, and encoded digital image data V _{cd, The} recording unit 23 is configured to record ₀ on the recording medium 13.

  The recording media 13 and 17 include, for example, a magnetic disk (including a flexible disk), an optical disk (including a CD-ROM (Compact Disc-Read Only Memory) and a DVD), a magneto-optical disk (including an MD (Mini Disc)), Alternatively, it consists of a semiconductor memory or the like.

The playback device 14 decodes the digital encoded data V _{rd, 0} read from the recording medium 13, and outputs a digital image signal V _dg0 obtained as a result to the digital-analog converter 32, and a digital The image signal V _dg0 is _converted into an analog signal, and the resulting analog image signal V _an1 is output from the display 15 and the digital / analog conversion section (D / A) 32 that outputs to the encoding device 16.

In the digital-analog conversion unit 32, when the digital image signal V _dg0 is converted into an analog signal due to the characteristics of a general analog-digital conversion circuit, the analog image signal V _an1 obtained as a result is converted into analog noise (referred to as white noise). Distortion or the like to which high-frequency components are added) occurs.

Here, the distortion to which the high frequency component generated in the analog image signal _Van1 is added will be described with reference to FIG. The left side of the figure shows the pixel values of five parallel pixels of the digital image signal V _dg0 before digital-analog conversion in the digital-analog conversion unit 32, and _assume that the pixel values are the same. When the analog image signal V _an1 to which high-frequency component distortion is added by digital-analog conversion is digitized by the analog-digital conversion unit 41 in the _subsequent stage, fluctuations occur in the same pixel value as shown on the right side of the figure. . This change is not regular and not uniform. Further, distortion of high frequency components is similarly applied not only in the horizontal direction but also in the vertical direction. Hereinafter, this distortion added through digital-analog conversion and analog-digital conversion is also referred to as white noise.

  Returning to FIG. The displays 15 and 17 are composed of a CRT (Cathode Ray Tube), an LCD (Liquid Crystal Display), or the like, and display an image corresponding to an input analog image signal.

The encoding device 16 digitizes the analog image signal V _an1 input from the reproduction device 14 and outputs the resulting digital image signal V _dg1 to the encoding unit 22-2, digital image signal 41 The encoding unit 22-2 that encodes V _dg1 and _{outputs the} resulting encoded digital image data V _cd to the recording unit 44 and the decoding unit 31-2, and the encoded digital image data V _cd to the recording medium 17 And a recording unit 44 that reads the encoded digital image data V _rd recorded on the recording medium 17 and supplies the encoded digital image data V _rd to the decoding unit 31-2.

Further, the encoding device 16 decodes the encoded digital image data V _cd supplied from the encoding unit 22-2 or the encoded digital image data V _rd supplied from the recording unit 44, and a digital image obtained as a result thereof From the decoding unit 31-2 that outputs the signal V _dg2 to the digital-analog conversion unit 46 and the digital-analog conversion unit 46 that converts the digital image signal V _dg2 into an analog signal and outputs the resulting analog image signal V _an2 to the display 18 Composed.

Note that the digital image signal V _dg1 output from the analog-to-digital conversion unit 41 has a high-frequency component distortion added to the analog image signal V _an1 before digitization, so that the decoding unit 31- Compared with the digital image signal V _dg0 output from 1, the pixel value slightly fluctuates (that is, a state with noise).

Further, a noise adding unit 42 is built in the analog-digital conversion unit 41, and after adding analog noise (noise corresponding to white noise) to the analog image signal _Van1 before being intentionally digitized, it is digitized. It may be.

  The encoding unit 22-1 in the encoding device 12 and the encoding unit 22-2 in the encoding device 16 have the same configuration (described later). Hereinafter, when there is no need to distinguish between the encoding unit 22-1 and the encoding unit 22-2, they are simply referred to as the encoding unit 22.

  Also, the decoding unit 31-1 in the playback device 14 and the decoding unit 31-2 in the encoding device 16 have the same configuration (described later). Hereinafter, when there is no need to distinguish between the decoding unit 31-1 and the decoding unit 31-2, they are simply referred to as the decoding unit 31.

  Next, the operation of the image display system 1 will be described with reference to FIG. The image display system 1 encodes and decodes an original image, and encodes and decodes a “first encoded / decoded image” obtained as a result, to obtain a “second encoded / decoded image”. Is output. The definitions of “first encoded / decoded image” and “second encoded / decoded image” are as follows.

That is, the original image shown in FIG. A corresponds to the analog image signal _Van0 output from the tuner 11. The “first encoded / decoded image” shown in FIG. B obtained by encoding and decoding the original image corresponds to the digital image signal V _dg0 output from the decoding unit 31-1 of the playback device 14. . The “image in which distortion is added to the first encoded / decoded image” shown in FIG. 3C corresponds to the analog image signal _Van1 output from the digital-analog conversion unit 32 of the playback device 14. The “second encoded / decoded image” shown in FIG. 4D is a digital image signal V _dg2 output from the decoding unit 31-2 of the encoding device 16, or the recording device 17 is decoded by the reproduction device 14. This corresponds to the digital image signal resulting from decoding by the unit 31-1.

  Next, details of the encoding unit 22 will be described. FIG. 4 shows a first configuration example of the encoding unit 22. The first configuration example of the encoding unit 22 includes a block dividing unit 61 that divides an input image into blocks of a predetermined size (for example, 8 × 8 pixels), and a feature amount (for example, an activity described later). Etc.), a reblocking unit 63 that further divides each block into 4 × 4 pixels or the like based on the detected feature amount, and a predetermined method (for example, The block coding unit 64 performs block coding using ADRC (Adaptive Dynamic Range Coding) or DCT (Discrete Cosine Transform).

  The operation of the first configuration example of the encoding unit 22 will be described with reference to the flowchart of FIG. 5 using the encoding unit 22-2 of the encoding device 16 as an example.

First, as step S1, noise is added to the analog image signal _Van1 before being digitized by the noise adding unit 42 of the analog-digital converting unit 41. However, the process of step S1 may be omitted.

In step S 2, the block division unit 61 divides the digital image signal V _dg1 (added with noise) input from the analog-digital conversion unit 41 into blocks of a predetermined size and outputs the blocks to the feature amount detection unit 62. . In step S3, the feature amount detector 62 detects the feature amount of each block divided in the process of step S2. In step S4, the reblocking unit 63 redivides each block based on the detected feature amount. At this time, there may be blocks that are not subdivided.

In step S5, the block encoding unit 64 performs block encoding on the subdivided block and the non-subdivided block by a predetermined method. Then, encoded digital image data V _cd obtained as a result of block encoding (information indicating whether each block has been subdivided, the minimum pixel value of each block, the dynamic range of each block, and the quantization code of each block) Are output to the subsequent stage. Thereafter, the encoded digital image data V _cd is recorded on the recording medium 17 by the recording unit 44 or decoded by the decoding unit 31-2. This is the end of the description of the operation of the encoding unit 22 according to the first configuration example.

  Note that other configuration examples (second and third configuration examples) and the operation of the encoding unit 22 will be described later with reference to FIG.

Next, the decoding unit 31 that performs decoding corresponding to the encoding by the encoding unit 22 will be described. FIG. 6 shows a configuration example of the decoding unit 31. The decoding unit 31 includes a block size determination unit 71 that determines the size of a block to be decoded based on the encoded digital image data V _cd input from the previous stage, and an inverse block code corresponding to the determined block size It comprises a block decoding unit 72 that performs (block decoding).

The operation of the decoding unit 31 corresponding to the operation according to the first configuration example of the encoding unit 22 will be described using the decoding unit 31-2 of the encoding device 16 as an example. The encoding unit 31-2 is supplied with encoded digital image data V _cd (or encoded digital image data V _rd read from the recording medium 17 by the recording unit 44) from the encoding unit 22-2. To do.

First, the block size determination unit 71 sequentially specifies blocks to be decoded based on the encoded digital image data V _cd supplied from the previous stage, determines the size thereof, and the determination result and the encoded digital image data V _cd Is output to the block decoding unit 72. Corresponding to this, the block decoding unit 72 performs inverse block encoding (block decoding) corresponding to the determined block size, and outputs the resulting digital image signal V _dg2 to the _subsequent stage. Since this digital image signal V _dg2 is the above-mentioned “second encoded / decoded image” and the image quality has deteriorated, the analog image signal V _{an1 is} to be copied using the encoding device 16. Is suppressed.

  Next, a second configuration example of the encoding unit 22 will be described with reference to FIG. This second configuration example shows the first configuration example shown in FIG. 4 in more detail.

  The second configuration example of the encoding unit 22 includes a block division unit 61 that divides an input image into 8 × 8 pixel blocks, and an activity calculation unit 81 that calculates an activity (described later) as a feature amount of each block. A quantity detection unit 62, a reblocking unit 63 that further subdivides each block into 4 × 4 pixels based on the calculated activity, and a block encoding unit that performs block encoding on the subdivided block by ADRC or DCT or the like 64.

  The reblocking unit 63 is a block size determining unit 82 that determines blocks included in the upper 25% of the blocks having the larger activity value among all blocks constituting the image, and block redividing the blocks included in the upper 25% A block size determination unit 83 that outputs a block not included in the upper 25% to the block encoding unit 64, and a block included in the upper 25% input from the block size determination unit 83. The block subdivision unit 84 is configured to subdivide into pixels and output to the block encoding unit 64.

The outline of the operation of the encoding unit 22 according to the second configuration example is as shown in FIG. That is, the original image shown in FIG. A (the digital image signal V _dg1 from the analog-digital converter 41 in the encoding unit 22-2) is divided into 8 × 8 pixel blocks as shown in FIG. Activity is calculated for each block of 8 × 8 pixels as shown in FIG. C (described later with reference to FIG. 9).

  Next, as shown in FIG. 4D, the upper 25% block with the larger activity value is subdivided into 4 × 4 pixels, and finally, as shown in FIG. The ADRC block encoding is performed with the subdivision block of × 4 pixels and the other blocks as they are (8 × 8 pixels).

Here, an activity calculation method will be described with reference to FIG. FIG. 9 shows an example in which the size of the block for calculating the activity is i × j pixels (i pixels in the horizontal direction and j pixels in the vertical direction). The pixel value of the upper left pixel of this block is L _v1,1, and the pixel value of the right adjacent pixel is L _v2,1 . The same applies to the pixel values of other pixels. The activity Act of this i × j pixel block is calculated using the following equation (1).

  As is clear from equation (1), the activity is the average value of the sum of the differences between the pixel values of each pixel included in the block and the pixels adjacent to the top, bottom, left, and right, and the variation in the pixel values of the pixels belonging to the block Is a value indicating. If the variation is large, the activity value is large, and if the variation is small, the activity value is small.

  In Expression (1), the difference between the pixel values of the pixel of interest and the upper, lower, left, and right pixels is calculated. However, the difference between the pixel value of the pixel of interest and the diagonal pixel is further calculated. May be. Further, the activity calculation is not limited to the equation (1), and any activity may be used as long as it indicates variations in pixel values of pixels belonging to the block.

  The operation of the encoding unit 22 according to the second configuration example will be described with reference to the flowchart of FIG. 10 using the encoding unit 22-2 of the encoding device 16 as an example.

In step S11, the block division unit 61 divides the digital image signal V _dg1 (added with noise) input from the analog-digital conversion unit 41 into 8 × 8 pixel blocks. In step S12, the activity calculation unit 81 of the feature amount detection unit 62 calculates the activity value of each block divided in the process of step S11.

  In step S13, the block size determination unit 82 of the reblocking unit 63 determines blocks included in the upper 25% of the larger activity values among all the blocks constituting the image, and the block size determination unit 83 Blocks included in the upper 25% are output to the block re-dividing unit 84, and blocks not included in the upper 25% are output to the block encoding unit 64. Then, the block re-dividing unit 84 re-divides the blocks included in the upper 25% into 4 × 4 pixels and outputs them to the block encoding unit 64.

In step S14, the block encoding unit 64 performs block encoding on the block subdivided into 4 × 4 pixels or the 8 × 8 pixel block using ADRC. Then, encoded digital image data V _cd obtained as a result of block encoding (information indicating whether each block has been subdivided, the minimum pixel value of each block, the dynamic range of each block, and the quantization code of each block) Are output to the subsequent stage. Thereafter, the encoded digital image data V _cd is recorded on the recording medium 17 by the recording unit 44 or decoded by the decoding unit 31-2. Above, description of operation | movement by the 2nd structural example of the encoding part 22 is complete | finished.

The operation of the decoding unit 31 corresponding to the operation by the second configuration example of the encoding unit 22 will be described with reference to FIG. Here, the decoding unit 31-2 of the encoding device 16 will be described as an example. The encoding unit 31-2 is supplied with encoded digital image data V _cd (or encoded digital image data V _rd read from the recording medium 17 by the recording unit 44) from the encoding unit 22-2. To do.

In step S21, the block size determination unit 71 sequentially designates blocks to be decoded based on the encoded digital image data V _cd supplied from the previous stage and determines the size (8 × 8 or 4 × 4 pixels). Then, the determination result and the encoded digital image data V _cd are output to the block decoding unit 72. If it is determined that the size of the block to be decoded is 4 × 4 pixels, the process proceeds to step S22. If it is determined that the size of the block to be decoded is 8 × 8 pixels, the process proceeds to step S23. move on.

In step S22, the block decoding unit 72 performs inverse block encoding (block decoding) corresponding to the block size of 4 × 4 pixels, and outputs the resulting digital image signal V _dg2 to the _subsequent stage. In step S23, the block decoding unit 72 performs inverse block encoding corresponding to the block size of 8 × 8 pixels, and outputs the resulting digital image signal V _dg2 to the _subsequent stage. Since this digital image signal V _dg2 is the above-mentioned “second encoded / decoded image” and the image quality has deteriorated, the analog image signal V _{an1 is} to be copied using the encoding device 16. Is suppressed.

Here, the digital image signal V _dg2 output from the decoding unit 31-2 (second encoding and decoding images), a digital image signal V _dg1 (1 st output from the decoding unit 31-1 The fact that the image quality is deteriorated compared to the encoded / decoded image will be described.

  FIG. 12 shows an outline when image quality deteriorates due to the second encoding / decoding. When the original image shown in FIG. 11A is encoded for the first time, the blocks belonging to the upper 25% with the larger activity are subdivided as shown in FIG. A block surrounded by a mark (hereinafter referred to as a target block) will be described as an example. Numbers 1, 2, 3, and 4 are given in the raster scan order to the 4 × 4 pixel four-division block after re-division when the target block is sub-division. It is assumed that block coding by 2-bit ADRC is performed on each divided block. Further, although there are 16 pixels in each actual divided block, only 4 pixels are shown for convenience of explanation and illustration.

  The pixel value of the original image shown in Fig. C becomes "the pixel value of the first encoding / decoding" shown in Fig. D after the first encoding / decoding, and the value close to the original signal is Can hold. However, even if a block has a small activity value in the first encoding, the activity value may increase by adding white noise in the second encoding. When white noise is added, a block that is subdivided into 4 × 4 pixels in the first encoding may be determined to be a block that is not subdivided in the second encoding (E in the figure).

  Now, it is assumed that the target block is a block that is not subdivided at the time of the second encoding. The “pixel value obtained by adding distortion to the pixel value after the first encoding / decoding” shown in FIG. F due to white noise has a slight error in the “pixel value after the first encoding / decoding”. This is the added pixel value. When block coding is performed without re-dividing the pixel value of the target block and decoding is performed, a “pixel value after second encoding / decoding” shown in FIG.

  As is clear by comparing the “pixel value after the second encoding / decoding” shown in FIG. 6G with the “pixel value of the original image” shown in FIG. C, the two are greatly different. In this way, if a block that has been subdivided into 4 × 4 pixels in the first encoding and block-encoded without being subdivided in the second encoding, a value separated from the original signal is obtained. This causes deterioration of the image. Naturally, the “pixel value after the second encoding / decoding” is the one in which the image quality is deteriorated even when compared with the “pixel value after the first encoding / decoding” shown in FIG. Become.

  Next, a third configuration example of the encoding unit 22 will be described with reference to FIG. This third configuration example shows the first configuration example shown in FIG. 4 in more detail.

  The third configuration example of the encoding unit 22 includes a block dividing unit 61 that divides an input image into 6 × 6 pixel basic blocks, and an equal dividing unit 91 that further divides each basic block into 3 × 3 pixel divided blocks. A feature amount detection unit 62 including an activity calculation unit 92 that calculates an activity as a feature amount of each divided block, and 2 × 2, 2 × 4, 4 × each basic block based on the calculated activity of each divided block. A re-blocking unit 63 including a sub-dividing unit 93 that sub-divides into 2 or 4 × 4 pixels, and a block coding unit 64 that performs block coding of the sub-divided divided block by ADRC or DCT or the like.

An outline of the operation of the third configuration example of the encoding unit 22 is as shown in FIG. That is, the original image shown in FIG. A (the digital image signal V _dg1 from the analog-to-digital converter 41 in the encoding unit 22-2) is divided into basic blocks of 6 × 6 pixels as shown in FIG. The basic block of 6 × 6 pixels shown in FIG. 6C is further divided into 3 × 3 pixel divided blocks as shown in FIG. D, and the activity is calculated for each divided block (about activity calculation). Is as described above with reference to FIG.

  Next, as shown in FIG. 5E, among the four divided blocks constituting the basic block, the one having the maximum activity value is determined, and as shown in FIG. 5F, the activity value is maximum. The basic block is divided again so as to reduce the size of the divided block. Then, ADRC block coding is performed on each divided block as shown in FIG.

  FIG. 15 shows four patterns for re-dividing the basic block. For example, when the activity value of the upper left of the four divided blocks (3 × 3 pixels) constituting the basic block is the maximum, as shown in FIG. The block is subdivided so that a divided block of 4 × 4 pixels is arranged at the lower right. Also, for example, when the activity value of the upper right one of the four divided blocks constituting the basic block is the maximum, a 2 × 2 pixel divided block is displayed at the upper right of the basic block as shown in FIG. Subdivision is performed so that 4 × 4 pixel division blocks are arranged.

  The operation of the third configuration example of the encoding unit 22 will be described with reference to the flowchart of FIG. 16, taking the encoding unit 22-2 of the encoding device 16 as an example.

In step S _<b> 31, the block dividing unit 61 divides the digital image signal V _dg1 (with noise added) input from the analog / digital converting unit 41 into basic blocks of 6 × 6 pixels, and _{supplies the result} to the feature amount detecting unit 62. Output. In step S32, the equal division unit 91 of the feature amount detection unit 62 further divides the basic block into basic blocks of 3 × 3 pixels. In step 33, the activity calculation unit 92 calculates the activity value of each divided block.

In step S34, the re-dividing unit 93 of the re-blocking unit 63 re-divides each basic block based on the calculated activity value. In step S35, the block encoding unit 64 performs block encoding on the re-divided block (2 × 2, 2 × 4, 4 × 2, or 4 × 4 pixels) using ADRC. Then, the encoded digital image data V _cd obtained as a result of the block encoding (information indicating which of the four patterns shown in FIG. 15 the basic block is subdivided into, and the pixel minimum of each divided block) Value, dynamic range of each divided block, and quantization code of each divided block). Thereafter, the encoded digital image data V _cd is recorded on the recording medium 17 by the recording unit 44 or decoded by the decoding unit 31-2. Above, description of operation | movement by the 3rd structural example of the encoding part 22 is complete | finished.

The operation of the decoding unit 31 corresponding to the operation of the third configuration example of the encoding unit 22 will be described with reference to FIG. Here, the decoding unit 31-2 of the encoding device 16 will be described as an example. The encoding unit 31-2 is supplied with encoded digital image data V _cd (or encoded digital image data V _rd read from the recording medium 17 by the recording unit 44) from the encoding unit 22-2. To do.

In step S41, based on the encoded digital image data V _cd supplied from the previous stage, the block size determination unit 71 sequentially designates basic blocks to be decoded and determines the subdivision pattern. The determination result and the encoded digital The image data V _cd is output to the block decoding unit 72. In step S42, the block decoding unit 72 performs inverse block encoding (block decoding) according to the size of the divided block, and outputs the resulting digital image signal V _dg2 to the _subsequent stage. Since this digital image signal V _dg2 is the above-mentioned “second encoded / decoded image” and the image quality has deteriorated, the analog image signal V _{an1 is} to be copied using the encoding device 16. Is suppressed.

Here, the digital image signal V _dg2 output from the decoding unit 31-2 (second encoding and decoding images), a digital image signal V _dg1 (1 st output from the decoding unit 31-1 The fact that the image quality is deteriorated compared to the encoded / decoded image will be described.

  FIG. 18 shows an outline when image quality deteriorates due to the second encoding / decoding. When the original image shown in FIG. A is encoded for the first time, each basic block is subdivided as shown in FIG. The target basic block) will be described as an example. Numbers 1, 2, 3, and 4 are given to the four divided blocks after re-division when the target basic block is sub-division in the raster scan order. It is assumed that block coding by 2-bit ADRC is performed on each divided block. Each actual divided block has 4, 8, 8, or 16 pixels, but the number of pixels is omitted for convenience of explanation and illustration.

  The pixel value of the original image shown in FIG. C becomes the “pixel value of the first encoding / decoding” shown in FIG. D after the first encoding / decoding, and is close to the original signal. Can hold. However, the target basic block was subdivided as shown in FIG. 15A in the first encoding, but was divided into 3 × 3 pixels by adding white noise in the second encoding. The activity value of the divided block may change, and the subdivision pattern may change. For example, as shown in FIG. 15E, the target basic block may be subdivided as shown in FIG. 15A in the second encoding.

  In this case, the “pixel value obtained by adding distortion to the pixel value after the first encoding / decoding” shown in FIG. F due to white noise is slightly smaller than the “pixel value after the first encoding / decoding”. It becomes a pixel value to which a simple error is added. When the pixel value of the target basic block is subdivided in a pattern different from the first time and block coding is performed and decoded, the pixel value after the second coding / decoding shown in FIG. "become that way.

  As is clear by comparing the “pixel value after the second encoding / decoding” shown in FIG. 6G with the “pixel value of the original image” shown in FIG. C, the two are greatly different. In this way, if the subdivision pattern at the first encoding and the subdivision pattern at the second encoding change, it has a value away from the original signal, which causes image degradation. . Naturally, the “pixel value after the second encoding / decoding” is the one in which the image quality is deteriorated even when compared with the “pixel value after the first encoding / decoding” shown in FIG. Become.

As described above, the analog image signal V _an1 output from the playback device 14 is distorted by high-frequency components due to the characteristics at the time of digital-analog conversion. Will not affect.

However, when the analog image signal V _an1 output from the reproduction device 14 is encoded again by the encoding device 16, the encoding device 16 is encoded so that the image quality is deteriorated at the time of decoding. However, this is not suitable for the purpose of copying an analog image signal.

In addition, with the knowledge that the reproduction result is deteriorated, the recording medium 17 on which the encoded digital image data V _cd is recorded by the encoding device 16 is reproduced by the reproduction device 14 or the like, and the reproduction result is encoded. In the case of re-encoding by 16, the image quality is further deteriorated at the time of decoding. Therefore, the encoding device 16 is not suitable for the second and subsequent copying of the analog image signal. Therefore, copying of analog data using the encoding device 16 is suppressed.

  By the way, the series of processes described above can be executed by hardware, but can also be executed by software. When a series of processing is executed by software, a program constituting the software may execute various functions by installing a computer incorporated in dedicated hardware or various programs. For example, a general-purpose personal computer configured as shown in FIG. 19 is installed from the recording medium.

  The personal computer 100 includes a CPU (Central Processing Unit) 101. An input / output interface 105 is connected to the CPU 101 via the bus 104. A ROM (Read Only Memory) 102 and a RAM (Random Access Memory) 103 are connected to the bus 104.

  The input / output interface 105 stores an input unit 106 including an input device such as a keyboard and a mouse for a user to input an operation command, an output unit 107 including a display for displaying a processing result image, and the like, and programs and various data. A storage unit 108 including a hard disk drive and a communication unit 109 that includes a modem, a LAN (Local Area Network) adapter, and the like and executes communication processing via a network represented by the Internet are connected. In addition, a drive 110 for reading / writing data from / to a recording medium 111 such as a magnetic disk (including a flexible disk), an optical disk (including a CD-ROM, a DVD), a magneto-optical disk (including an MD), or a semiconductor memory is connected. Has been.

  A program for causing the personal computer 100 to execute the above-described series of processing is supplied to the personal computer 100 while being stored in the recording medium 111, read by the drive 110, and installed in a hard disk drive built in the storage unit 108. Has been. The program installed in the storage unit 108 is loaded from the storage unit 108 to the RAM 103 and executed in response to a command from the CPU 101 corresponding to a command from the user input to the input unit 106.

  In this specification, the steps executed based on the program are executed in parallel or individually even if they are not necessarily processed in time series, as well as processes executed in time series according to the described order. It also includes processing.

  The program may be processed by a single computer, or may be distributedly processed by a plurality of computers. Furthermore, the program may be transferred to a remote computer and executed.

  Further, in this specification, the system represents the entire apparatus constituted by a plurality of apparatuses.

It is a block diagram which shows the structural example of the image display system to which this invention is applied. It is a figure for demonstrating white noise. It is a figure for demonstrating the operation | movement outline | summary of an image display system. It is a block diagram which shows the 1st structural example of the encoding part in FIG. 5 is a flowchart for explaining the operation of the first configuration example of the encoding unit shown in FIG. 4. It is a block diagram which shows the structural example of the decoding part in FIG. It is a block diagram which shows the 2nd structural example of the encoding part in FIG. It is a figure for demonstrating the operation | movement outline | summary by the 2nd structural example of the encoding part shown by FIG. It is a figure for demonstrating the calculation method of activity. FIG. 8 is a flowchart for explaining the operation of the second exemplary configuration of the encoding unit shown in FIG. 7. FIG. FIG. 8 is a flowchart for explaining the operation of a decoding unit corresponding to the second configuration example of the encoding unit shown in FIG. 7. FIG. It is a figure for demonstrating the effect by the 2nd structural example of the encoding part shown by FIG. It is a block diagram which shows the 3rd structural example of the encoding part in FIG. It is a figure for demonstrating the operation | movement outline | summary by the 3rd structural example of the encoding part shown by FIG. It is a figure which shows four patterns which subdivide a basic block. It is a flowchart explaining the operation | movement by the 3rd structural example of the encoding part shown by FIG. It is a flowchart explaining the operation | movement of the decoding part corresponding to the 3rd structural example of the encoding part shown by FIG. It is a figure for demonstrating the effect by the 3rd structural example of the encoding part shown by FIG. It is a block diagram which shows the structural example of the personal computer to which this invention is applied.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Image display system, 12 encoding apparatus, 14 reproducing | regenerating apparatus, 16 encoding apparatus, 22 encoding part, 31 decoding part, 32 digital analog conversion part, 41 analog digital conversion part, 42 noise addition part, 61 block division part 62 feature quantity detection unit, 63 reblocking unit, 64 block encoding unit, 71 block size determining unit, 72 block decoding unit, 81 activity calculating unit, 82 block size determining unit, 83 block size determining unit, 84 blocks Subdivision unit, 91 equal division unit, 92 activity calculation unit, 93 subdivision unit, 100 personal computer, 101 CPU, 111 recording medium

Claims (11)

In an encoding device for encoding input image data,
Block dividing means for dividing the image data into basic blocks of a predetermined uniform size;
Subdivide each basic block is split into smaller uniform size of the divided blocks, as a feature amount indicating a feature of image data in the divided blocks, the activity showing the variation in the pixel values of pixels constituting the divided blocks A feature amount detecting means for detecting;
Based on the activity detected for each divided block of the basic block, for each basic block, the size of the divided block having the largest variation in pixel values among the plurality of divided blocks is reduced. Re-blocking means for re-blocking the basic block into non-uniform re-divided blocks by changing the size of the other divided blocks ;
The basic block including the encoding apparatus and an encoding means for encoding said image data for each of the subdivided blocks reblocked. Noise is added to the image data.
Encoding apparatus according to 請 Motomeko 1. The encoding apparatus according to still including claim 1 noise adding means for outputting the block dividing means adds noise to the inputted image data. The image data is decoded after being encoded at least once.
Encoding apparatus according to 請 Motomeko 1. Said encoding means applies the ADRC (Adaptive Dynamic Range Coding), the basic blocks to encode the image data for each of the subdivided blocks reblocked
Encoding apparatus according to 請 Motomeko 1. The encoding means includes a code obtained as a result of encoding the image data for each re-divided block in which the basic block has been re-blocked , and a size of the non-uniform re-divided block that has been re-blocked. Output encoded data including at least
Encoding apparatus according to 請 Motomeko 1. The encoding apparatus according to still including claim 6 decoding means for decoding the encoded data output from said encoding means. In an encoding method of an encoding device for encoding input image data,
A block dividing step of dividing the image data into basic blocks of a predetermined uniform size;
Subdivide each basic block is split into smaller uniform size of the divided blocks, as a feature amount indicating a feature of image data in the divided blocks, the activity showing the variation in the pixel values of pixels constituting the divided blocks A feature amount detection step to detect;
Based on the activity detected for each divided block of the basic block, for each basic block, the size of the divided block having the largest variation in pixel values among the plurality of divided blocks is reduced. A reblocking step of reblocking the basic block into a non-uniform subdivision block by changing the size of the other subdivision blocks ;
The basic block is re-blocked coding step and the including coding method for encoding the image data for each of the re-divided block. A program for controlling an encoding device that encodes input image data,
A block dividing step of dividing the image data into basic blocks of a predetermined uniform size;
Subdivide each basic block is split into smaller uniform size of the divided blocks, as a feature amount indicating a feature of image data in the divided blocks, the activity showing the variation in the pixel values of pixels constituting the divided blocks A feature amount detection step to detect;
Based on the activity detected for each divided block of the basic block, for each basic block, the size of the divided block having the largest variation in pixel values among the plurality of divided blocks is reduced. A reblocking step of reblocking the basic block into a non-uniform subdivision block by changing the size of the other subdivision blocks ;
The basic block is re-blocked the re-division encoding step and recording medium processing Ru cause the computer to execute the encoding device program is recorded comprising for encoding the image data for each block. A program for controlling an encoding device that encodes input image data,
A block dividing step of dividing the image data into basic blocks of a predetermined uniform size;
Subdivide each basic block is split into smaller uniform size of the divided blocks, as a feature amount indicating a feature of image data in the divided blocks, the activity showing the variation in the pixel values of pixels constituting the divided blocks A feature amount detection step to detect;
Based on the activity detected for each divided block of the basic block, for each basic block, the size of the divided block having the largest variation in pixel values among the plurality of divided blocks is reduced. A reblocking step of reblocking the basic block into a non-uniform subdivision block by changing the size of the other subdivision blocks ;
The basic block is a program Ru to execute the processing including an encoding step of encoding the image data for each of the subdivided blocks reblocked into the computer of the encoding device. An image that includes an encoding unit that encodes image data and a decoding unit that decodes the output of the encoding unit, and the image data is deteriorated when encoding and decoding are repeated on the image data In the processing system,
The encoding unit includes:
Block dividing means for dividing the image data into basic blocks of a predetermined uniform size;
Subdivide each basic block is split into smaller uniform size of the divided blocks, as a feature amount indicating a feature of image data in the divided blocks, the activity showing the variation in the pixel values of pixels constituting the divided blocks A feature amount detecting means for detecting;
Based on the activity detected for each divided block of the basic block, for each basic block, the size of the divided block having the largest pixel value variation among the plurality of divided blocks is reduced, and accordingly Re-blocking means for re-blocking the basic block into non-uniform re-divided blocks by changing the size of the other divided blocks ;
Look including an encoding means for said basic block to encode the image data for each re-blocked the re-divided block,
The decoding unit
Analyzing means for analyzing encoded data that is a result of the image data being divided into predetermined subdivision blocks and encoded in units of the subdivision blocks by the encoding unit;
Decoding means for decoding the encoded data in units of the re-divided blocks based on the analysis result by the analysis means
Images processing system.

Images