JP2009246540A - Encoding device, encoding method, and encoding program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce an encoding delay and deterioration of image data which is finally obtained. <P>SOLUTION: An encoding device variably determines the size of partial areas for dividing an input image within a maximum size determined by an allowable encoding delay time, and divides the input image into the partial areas. Then the encoding device allocates a code amount to be used to encode the partial areas according to the size of the partial areas which is determined and used to divide the input image. Thus, the encoding device encodes the partial areas whose size is determined with the allocated code amount. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an encoding device, an encoding method, and an encoding program that divide an inputted input image into partial areas and encode the partial areas with a predetermined code amount.

  2. Description of the Related Art Conventionally, there is a technique for setting the amount of encoded data to a constant amount in units of images (pictures) or in units of images (Patent Document 1). In the encoding apparatus in this image processing system, for example, when the code amount is made constant in units of one picture, the encoded data output time becomes constant in units of one picture as shown in FIG.

  Specifically, as illustrated in FIG. 14, the encoding device according to Patent Document 1 receives a code amount control unit that controls a code amount constant in units smaller than a picture or a picture, and a code amount control unit. An encoding unit that encodes input image data based on the code amount, and a code amount calculation unit that calculates the code amount of the encoded data encoded by the encoding unit and feeds it back to the code amount control unit. The

  As shown in FIG. 15, the encoding apparatus having such a configuration divides an input image into six parts, and makes an upper limit code amount (for example, 20 bits) usable in each region constant. In other words, the encoding device includes the areas “0, 1, 2, 3”, the areas “4, 5, 6, 7”, the areas “8, 9, 10, 11”, and the areas “12, 13, 14, 15”. , Encoding is performed by controlling the code amounts of the regions “16, 17, 18, 19” and “20, 21, 22, 23” to be constant. For example, the encoding apparatus encodes each image block such that “0, 1, 2, 3”, which is one area, falls within a predetermined code amount. Then, the encoding device sequentially transmits the encoded data from the encoded data to the decoding device. Further, since the encoded data output time is also constant by making the code amount constant, if the code amount is made constant for each unit below the screen, the delay can be reduced as a result.

JP 2001-169281 A

  However, although the above-described conventional technique can realize a low encoding delay, there is a problem that the quality of finally obtained image data deteriorates.

  Specifically, in the above-described conventional technique, when the encoding delay is reduced, the amount of code is controlled for each fixed unit in the picture, and thus the complexity in the picture cannot be dealt with. In other words, in the conventional technique, the input image is divided uniformly, and the amount of code that can be used in the divided area is constant. Therefore, both the complex image block and the uncomplicated image block in the area have the same code amount. Are allocated and encoded. In other words, a complicated image block is encoded data with a smaller code amount than when the original image data is encoded, and an uncomplicated image block is encoded with a larger code amount than when the original image data is encoded. May be data. Since the encoded data is decoded as it is, a complex image block encoded with a small code amount has a lower image quality than the original image data when decoded.

  Therefore, the present invention has been made to solve the above-described problems of the prior art, can reduce the delay of encoding, and can reduce deterioration of finally obtained image data. An object is to provide a certain encoding device, encoding method, and encoding program.

  In order to solve the above-described problems and achieve the object, the present invention is an encoding device that divides an inputted input image into a plurality of partial areas and encodes the partial areas with a predetermined code amount. A size determining means for determining the size of each of the partial areas, with an area corresponding to an allowable encoding delay time as a maximum value, and depending on the size of the partial area determined by the size determining means, A code amount allocating unit for allocating a code amount; and an encoding unit for encoding the partial area whose size is determined by the size determining unit with the code amount allocated by the code amount allocating unit. And

  According to the present invention, it is possible to reduce the encoding delay, and it is possible to reduce the degradation of finally obtained image data.

  Exemplary embodiments of an encoding device, an encoding method, and an encoding program according to the present invention will be described below in detail with reference to the accompanying drawings. In the following, the outline and features of the encoding apparatus according to the present embodiment, the configuration of the encoding apparatus, and the flow of processing will be described in order, and finally various modifications to the present embodiment will be described.

[Outline and Features of Encoding Device]
First, the outline and features of the encoding apparatus according to the first embodiment will be described with reference to FIG. FIG. 1 is a diagram for explaining the outline and features of the encoding apparatus according to the first embodiment.

  The encoding apparatus according to the first embodiment is to divide an input image that has been input into partial areas and to encode the partial areas with a predetermined code amount. The main feature is that delay can be achieved and deterioration of finally obtained image data can be reduced.

  This main feature will be specifically described. In this encoding apparatus, the allowable encoding delay time is 1/2 row, that is, the maximum size of the partial area is “4”, and the target value of the generated code amount per image block is “5”. . In addition, since the encoding amount is generally proportional to the complexity, the encoding apparatus determines the region size and the encoding amount with the complexity “1” as the expected encoding amount “1” and performs encoding.

  For example, in such a state, the encoding apparatus to which the image having the complexity shown in FIG. 1A is input has the region size fixed to “4”, and the encoding device shown in FIG. As shown in FIG. 4, encoding is performed so that the code amount is “20” in four image blocks. However, as shown in FIG. 1 (b2), the encoding apparatus sets the expected code amount of the first image block to “8”, the expected code amount of the second image block to “2”, and the predicted third image block. Since the code amount is “9” and the expected code amount of the fourth image block is “9”, the total expected code amount of the first partial area is “26”, and the code amount is reduced by “6” for encoding. Will be. Further, the total of the expected code amounts of the next partial area is “10”, and the code amount “10” is increased so as to be the assigned code amount “20”.

  On the other hand, when the region size is set to “4” at the maximum, the encoding apparatus, as shown in (c1) of FIG. 1, has a minimum size of the target value “5” for one image block and a maximum size of 4 images. As the block target value “20”, the region size can be changed variably, and the shortage of the code amount and the padding can be alleviated. Specifically, as shown in (c2) of FIG. 1, the encoding apparatus determines that the expected code amount of the first image block is “8” and the expected code amount of the second image block is “2”. The two image blocks are encoded as one partial area. Next, the encoding apparatus sets the expected code amount of the first image block to “9”, the expected code amount of the second image block to “9”, the expected code amount of the third image block to “2”, and the four image blocks. Since the predicted code amount of the eye is “0”, these four image blocks are encoded as one partial area.

  In this way, the encoding apparatus determines the size of each partial area with the area corresponding to the allowable encoding delay time as a maximum value, and sets the code amount according to the determined size of the partial area. The partial area whose size is determined can be encoded with the allocated code amount.

  Next, referring to FIG. 2, the encoding apparatus variably determines the size of the partial area for the input image and assigns a code amount according to the determined size of the partial area. The overall flow will be described. FIG. 2 is a diagram illustrating the encoding process according to the first embodiment.

  As shown in FIG. 2, when an image composed of image blocks “0 to 23” is input, this encoding apparatus sets the range within the maximum size determined by the allowable encoding delay time to 4 and the range. The size of the partial area is determined. As a specific example, the encoding apparatus, for an image composed of input image blocks “0 to 23”, has a size 4 of a partial area 1 “0 to 3” and a partial area 2 “4”. ", Size 4 of the partial area 3" 5-8 ", size 4 of the partial area 4" 9-12 ", size 1 of the partial area 5" 13 ", size 1 of the partial area 6" 14 " The area division / size is determined to be the size 2 of the area 7 “15, 16”, the size 3 of the partial area 8 “17-19”, and the size 4 of the partial area 9 “20-23”.

  Then, the encoding device allocates a code amount according to the determined size of the partial region, and encodes the partial region whose size is determined with the allocated code amount. In the example in which the target value of the generated code amount per image block is “5”, the encoding device has a generated code amount of “20” and a portion of size 1 in the partial area 1 of size 4. The generated code amount “5” is generated in the region 2, the generated code amount “20” is generated in the partial region 3 having the size 4, and the generated code amount “20” is generated in the partial region 4 having the size 4. The generated code amount is “5”, the generated code amount is “5” for the partial area 6 of size 1, the generated code amount is “10” for the partial area 7 of size 2, and the partial area 8 of size 3 is The generated code amount “20” is assigned to the partial area 9 having the generated code amount “15” and the size 4. Then, the encoding device encodes each region in order and transmits it to the decoding device.

  As described above, the encoding apparatus according to the first embodiment alleviates the bias of local code amount allocation by changing the division position by controlling the size of the region into which the input image is divided. As a result of being able to perform code amount control in accordance with the distribution of (predicted code amount), it is possible to reduce the encoding delay as in the main feature described above, and to reduce the deterioration of the finally obtained image data. It is possible.

[Configuration of Encoding Device]
Next, the configuration of the encoding apparatus shown in FIGS. 1 and 2 will be described with reference to FIG. FIG. 3 is a block diagram illustrating the configuration of the encoding apparatus according to the first embodiment. As illustrated in FIG. 3, the encoding device 10 includes a code amount adjustment region control unit 11, a code amount control unit 12, an encoding unit 13, and a code amount calculation unit 14.

  As shown in FIG. 4, the code amount adjustment region control unit 11 includes a block extraction unit 11a, a complexity calculation unit 11b, and a region size calculation unit 11c, which correspond to an allowable encoding delay time. The process of determining the size of each partial area is executed with the area to be processed as the maximum value. FIG. 4 is a diagram for explaining a detailed processing unit of the code amount adjustment region control unit.

  The block extraction unit 11a extracts an image block from the input image. To give a specific example, the block extraction unit 11a receives an input image from an image input device such as a video camera, extracts an image block from the received input image, and a complexity calculation unit described later on the extracted image block To 11b.

  The complexity calculation unit 11b calculates the complexity for each image block extracted from the input image. Specifically, when the complexity calculation unit 11b receives an image block extracted from the input image from the block extraction unit 11a, the complexity calculation unit 11b calculates the complexity for each received image block, and calculates the calculated image block. Each complexity is output to the area size calculation unit 11c described later.

  As a complexity calculation method, for example, when the size of an image block is 16 pixels × 16 pixels, the complexity calculation unit 11b can use a variance of 256 pixels constituting the image block. Specifically, an average value of 256 pixels (16 pixels × 16 pixels) constituting the image block is obtained, and a value obtained by squaring the difference from the obtained average value for each pixel is calculated. The average is the variance. The complexity is calculated from this variance value. The complexity increases as the variance value increases, and the complexity decreases as the variance value decreases.

  Further, for example, the complexity calculation unit 11b can obtain an average value for every several pixels constituting the image block and use the variance of the average value. Specifically, when calculating the variance of the average value for every four pixels, the complexity calculating unit 11b first obtains the average value for every four pixels and calculates the average value of 64 (16 pixels × 16 pixels / 4 pixels). The variance value may be calculated from Therefore, the calculation cost can be reduced as compared with the case where the variance value of 256 pixels (16 pixels × 16 pixels) is calculated.

  Further, for example, the complexity calculation unit 11b can use two-dimensional DCT (Discrete Cosine Transform). Specifically, the complexity calculation unit 11b can obtain a 16 × 16 frequency component by performing two-dimensional DCT on a 16 × 16 pixel. The complexity calculation unit 11b increases the complexity as the obtained frequency component is higher, and decreases as the obtained frequency component is lower.

  Regardless of which method is used, the complexity calculation unit 11b may use the obtained dispersion value or frequency component itself as the complexity, or may use the value obtained by further calculation as the complexity. Thus, the complexity calculation unit 11b that has calculated the complexity for each image block of the input image outputs the complexity for each image block obtained by the calculation to the region size calculation unit 11c described later.

  The region size calculation unit 11c determines the size of each partial region, with the region corresponding to the allowable encoding delay time as a maximum value. Specifically, the region size calculation unit 11c sets the region corresponding to the allowable encoding delay time as the maximum value according to the number of image blocks received from the complexity calculation unit 11b and the complexity of each image block. Determine the size of each of the partial areas. Here, the maximum value of the partial area is an encoding delay time that is allowed by the encoding unit 13 that executes the encoding process described later. For example, when it is ½ row, the maximum value is “4”. Is “8”. Further, a smaller value may be used as long as it is within an allowable delay time. In this way, the region size calculation unit 11c divides the input image into a plurality of regions below the predetermined maximum value, and outputs the divided result to the code amount control unit 12 described later.

  Returning to FIG. 3, the code amount control unit 12 assigns a code amount according to the size of the partial region determined by the code amount adjustment region control unit 11. Specifically, the code amount control unit 12 sets the code size (complexity, target code amount) of one size to “5” for the partial region determined and input by the code amount adjustment region control unit 11. If the size is “3”, the code amount “15” is assigned to the partial area. Then, the code amount control unit 12 outputs the partial region size “3” and the assigned target code amount “15” to the encoding unit 13 described later. Further, the target code amount of the next partial area to be output to the encoding unit 13 is finely adjusted in consideration of the difference between the actual code amount fed back from the code amount calculation unit 14 and the target code amount.

  The encoding unit 13 encodes the partial area having the determined size with the code amount allocated by the code amount control unit 12. As a specific example, the encoding unit 13 receives an input image composed of image blocks “0 to 23” and receives a size “4” and a code amount “20” from the code amount control unit 12. The image blocks “0 to 3” of the input image are encoded with the code amount “20”. For example, the encoding unit 13 encodes the image block “0” with the code amount “12” and the remaining image blocks “1 to 3” by subtracting “12” from the target code amount “20”. 8 ”. Thus, the encoding unit 13 uses the image block included in the region size allocated by the code amount control unit 12 in accordance with the complexity within the code amount allocated by the code amount control unit 12. The code amount is determined and encoded. Note that the encoding unit 13 does not need to be configured by one function unit, and may have a plurality of functions.

  The code amount calculation unit 14 feeds back the code amount and transmits the generated encoded data to the decoding device. As a specific example, the code amount calculation unit 14 extracts the code amount of the encoded data input by the encoding unit 13 and feeds it back to the code amount control unit 12, and decodes the encoded data. To the device.

[Processing by encoding device]
Next, processing performed by the encoding device will be described with reference to FIGS. 5 and 6. FIG. 5 is a flowchart illustrating a flow of region size determination processing in the encoding device according to the first embodiment, and FIG. 6 is a flowchart illustrating a flow of encoding processing in the encoding device according to the first embodiment.

(Flow of area size determination process)
As illustrated in FIG. 5, the encoding device 10 that has started the encoding process initializes a work variable (step S101). Specifically, the encoding apparatus 10 sets “p” indicating an image block currently being processed as “p = 1” as a work variable, and “t = 1” indicating “t” indicating the received image block. And

The encoding apparatus 10 that has initialized the variable receives the complexity of the image block (step S102). Specifically, in the above example, the encoding apparatus 10 receives an image block with “C _t = complexity, t <p + M” (M: maximum value of the number of code amount adjustment blocks).

Then, the encoding apparatus 10 updates the number of received image blocks (step S103), and calculates the average complexity of each received image block (step S104). More specifically, the encoding apparatus 10 updates the number of received image blocks as “t = p + M” and calculates the average complexity using the calculation formula shown in Formula (1). Note that “S _{i, j} ” shown in Expression (1) indicates “average of j complexity from image block i”.

Thereafter, the encoding apparatus 10 acquires the maximum value “S _{i, j} ” that is equal to or lower than the target value B of the complexity from “S _{i, j} ” calculated using the equation (1) (step S105). .

Then, when the maximum “S _{i, j} ” can be acquired below the complexity target value B (Yes in step S106), the encoding apparatus 10 sends the processed image block number “j” to the encoding unit 13. Then, the number of image blocks being processed “p” is updated to “p = p + j” (step S109).

  The encoding device 10 that has updated the number of image blocks being processed has the updated image block number “p” larger than “N (number of image blocks per picture)” (No in step S110), that is, input When the processes in steps S102 to S109 described above are executed for all the image blocks of the images that have been processed, the process ends.

  On the other hand, the encoding apparatus 10 that has updated the number of image blocks being processed has the updated image block number “p” equal to or less than “N (number of image blocks per picture)” (Yes in step S110), that is, In the input image, when there is an image block for which the processes in steps S102 to S109 are not executed, the process returns to step S102 and the subsequent processes are executed.

Returning to step S106, when the encoding device 10 cannot obtain the maximum “S _{i, j} ” below the complexity target value B (No in step S106), the above-described “S _{i, j} ” is the minimum. A thing is acquired (step S107), and the process after step S108 is performed.

Here, the processing of the above-described steps S101 to S110 will be described with a specific example. When the encoding device 10 receives four image blocks having the complexity “C ₁ = 8, C ₂ = 2, C ₃ = 9, C ₄ = 8”, the encoding device 10 sets the received image block number “t” to “t”. = 1 + 4 = 5 ". Here, it is assumed that the maximum value “M = 4” of the number of code amount adjustment blocks and the target value of complexity (standard amount of code used per image block) “B = 5”.

Then, the encoding device 10 calculates “S _1,1 = _8/1 = 8”, “S _1,2 = (8 + 2) / 2 = 5”, “S _1,3 = ( 8 + 2 + 9) /3=6.33..., “S _1,4 = (8 + 2 + 9 + 8) /4=6.75”.

Subsequently, the encoding apparatus 10 calculates the above-described “S _1,1 = 8”, “S _1,2 = 5”, “S _1,3 = 6.33”, “S _1,4 = 6.75”. ", The maximum" S _1,2 = 5 "is obtained with the target value" B = 5 "or less.

Then, the encoding device 10 updates the number of processed image blocks = 2 and the number of processed image blocks p = 1 + 2 = 3 based on the acquired “S _1,2 = 5”, and the next image block is updated. Receive. That is, the encoding apparatus 10 determines the processing size as “2”, and “C ₁ = 8, C ₂ = 2” is one area.

Thereafter, it is assumed that the encoding apparatus 10 further receives the complexity “C ₅ = 2 and C ₆ = 3”. That is, here, four image blocks of “C ₃ = 9, C ₄ = 8, C ₅ = 2 and C ₆ = 3” are received, but the size is undecided. Also, since the number of image blocks being processed p = 3, the encoding apparatus 10 performs the above-described processing on image blocks received after “C ₃ = 9”.

Similarly, the encoding apparatus 10 updates the number of received image blocks “t” to “t = 3 + 4 = 7” and sets “S _3,1 = _9/1 = 9” as an average of each complexity. "S _3,2 = (9 + 8) /2=8.5", "S _3,3 = (9 + 8 + 2) /3=6.33 ...", "S _3,4 = (9 + 8 + 2 + 3) / 4 = 5.5 "is calculated.

Subsequently, the encoding apparatus 10, the calculated "S _{3, 1} = 9", "S _3,2 = 8.5", "S _3,3 = 6.33 ···", "S _{3, 4} = 5.5 ", there is no target value" B = 5 "or less, so the minimum" S _3,4 = 5.5 "is acquired.

Then, the encoding device 10 updates the number of processed image blocks = 4 and p = 3 + 4 = 7 based on the acquired “S _3,4 = 5.5”, and receives the next image block. In other words, the encoding apparatus 10 determines the processing size as “4”, and “C ₃ = 9, C ₄ = 8, C ₅ = 2 and C ₆ = 3” is one area.

  Thus, the encoding apparatus 10 determines the partial region size sequentially from the complexity of the received number of image blocks.

(Encoding process flow)
As illustrated in FIG. 6, when an image is input (Yes in step S201), the encoding device 10 extracts an image block of the input image (input image), and extracts each of the extracted image blocks. After calculating the complexity, the region size is calculated (steps S202 to S204). The processing from step S201 to step S204 shown here is performed using the method described in FIG.

  Then, the encoding device 10 determines the target code amount and performs encoding (step S206) while acquiring the already used code amount as feedback information for each determined partial region (step S205). And step S207).

  The encoding apparatus 10 that has performed encoding calculates and feeds back the actual code amount (steps S208 to S209), and transmits encoded data obtained by encoding the input image to the decoding apparatus (step S210). .

  When the encoding apparatus 10 finishes transmitting the encoded data for one picture (input image) (Yes in step S211), the encoding apparatus 10 ends the process and finishes transmitting the encoded data for one picture (input image). If not (No at step S211), the process returns to step S201 to repeat the above-described processing.

[Comparison with conventional technology]
Then, when an image is input, the encoding device according to the related art, as shown in FIG. 7 (the number shown in FIG. 7 indicates complexity), the image is represented in a certain unit (4 image blocks). (Partial areas 1 to 6). Since the encoding apparatus according to the conventional technique encodes each partial region with a constant code amount (for example, 20 (when the target code amount is 5 for one image block)), FIG. As shown in FIG. 4, for the partial area 1, the partial area 4, and the partial area 6, the code amount is insufficient and it is necessary to perform a significant code amount reduction. On the other hand, the partial area 2, the partial area 3, and the partial area 5 As for, and the code amount is excessive, it is necessary to adjust. That is, in the encoding apparatus according to the related art, as shown in FIG. 9, for an area that requires a code amount exceeding the target code amount, a large amount is necessary to delete the code amount. Therefore, the obtained image data deteriorates.

  On the other hand, when the same image as the above-described image is input, the encoding device according to the present invention sets the region corresponding to the allowable encoding delay time to the maximum value (4) as shown in FIG. ), The respective sizes of the partial areas are determined (partial areas 1 to 9). Then, the encoding apparatus determines the code amount determined according to the size of each partial area (for example, the code amount is 5 when the size is 1, the code amount is 10 when the size is 2, and the code amount is 4 when the size is 4. Since the encoding is performed with the code amount 20), as shown in FIG. 11, all the partial regions 1 to 9 do not cause an event such as a shortage or a surplus of code amount as in the prior art. Regions can be encoded. That is, in the encoding apparatus according to the present invention, as shown in FIG. 12, all the partial regions can be encoded without exceeding the target code amount corresponding to the size of the region. Data deterioration can be reduced.

  FIG. 7 is a diagram illustrating an example of image division using the conventional technique, FIG. 8 is a diagram illustrating a used code amount after image division in the conventional technique, and FIG. 9 is a diagram after image division in the conventional technique. 10 is a diagram illustrating an example of image division using the present invention, and FIG. 11 is a diagram illustrating a used code amount after image division according to the present invention. 12 is a diagram illustrating a code amount deletion amount after image division according to the present invention.

[Effects of Example 1]
Thus, according to the first embodiment, the area corresponding to the allowable encoding delay time is set as the maximum value, the respective sizes of the partial areas are determined, and according to the determined size of the partial areas, Since the amount of code is allocated and the determined partial area is encoded with the allocated amount of code, it is possible to reduce the delay of encoding and to reduce the degradation of the finally obtained image data It is.

  Further, according to the first embodiment, since the size of the partial region is determined according to the complexity of the image included in the partial region, the code amount for each image block is flexibly allocated, and the local code amount bias is determined. As a result, it is possible to further reduce the degradation of finally obtained image data.

  Although the embodiments of the present invention have been described so far, the present invention may be implemented in various different forms other than the embodiments described above. Therefore, as shown below, (1) complexity calculation method, (2) encoding method, (3) system configuration, etc., (4) different embodiments will be described by being divided into programs.

(1) Complexity calculation method For example, this encoding apparatus can use various methods as the above-described complexity calculation method. For example, the encoding apparatus may calculate the complexity by using the variance for all the pixels constituting the image block, using the variance for the average of several pixels, or using the two-dimensional DCT. it can.

(2) Coding method Further, for example, the coding apparatus according to the present invention can code the partial area whose size is determined with the assigned code amount in the order of the screen of the input image. By doing so, it is possible to encode and output in the input order by encoding using the processing target image block or the image data that has already been input. It is possible to make it.

(3) System configuration etc. In addition, among the processes described in the present embodiment, all or a part of the processes (for example, image input processes) described as being automatically performed can be manually performed. . In addition, the processing procedure, control procedure, specific name, and information including various data and parameters shown in the above-described document and drawings can be arbitrarily changed unless otherwise specified.

  Further, each component of each illustrated apparatus is functionally conceptual, and does not necessarily need to be physically configured as illustrated. In other words, the specific form of distribution / integration of each device is not limited to that shown in the figure, and all or a part thereof may be functionally or physically distributed or arbitrarily distributed in arbitrary units according to various loads or usage conditions. For example, the code amount adjustment region control unit and the encoding unit may be integrated. Further, all or any part of each processing function performed in each device may be realized by a CPU and a program analyzed and executed by the CPU, or may be realized as hardware by wired logic.

(4) Program The encoding method described in the present embodiment can be realized by executing a program prepared in advance on a computer such as a personal computer or a workstation. This program can be distributed via a network such as the Internet. The program can also be executed by being recorded on a computer-readable recording medium such as a hard disk, a flexible disk (FD), a CD-ROM, an MO, and a DVD and being read from the recording medium by the computer.

  As described above, the encoding apparatus, encoding method, and encoding program according to the present invention are useful for dividing an input image that has been input into partial areas and encoding the partial areas with a predetermined code amount. In particular, the present invention is suitable for reducing the encoding delay and the deterioration of the finally obtained image data.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram for explaining an overview and characteristics of an encoding apparatus according to a first embodiment. It is a figure which shows the encoding process which concerns on Example 1. FIG. 1 is a block diagram illustrating a configuration of an encoding apparatus according to Embodiment 1. FIG. It is a figure for demonstrating the detailed process part of a code amount adjustment area | region control part. 6 is a flowchart illustrating a flow of region size determination processing in the encoding device according to the first embodiment. 6 is a flowchart illustrating a flow of an encoding process in the encoding device according to the first embodiment. It is a figure which shows the example of an image division using a prior art. It is a figure which shows the used code amount after the image division | segmentation in a prior art. It is a figure which shows the code amount deletion amount after the image division in a prior art. It is a figure which shows the example of an image division using this invention. It is a figure which shows the used code amount after the image division | segmentation in this invention. It is a figure which shows the code amount deletion amount after the image division | segmentation in this invention. It is a figure which shows the flow from the encoding process of a prior art to a decoding process. It is a figure which shows the structure of the encoding apparatus which concerns on a prior art. It is a figure which shows the flow of the encoding process of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Encoding apparatus 11 Code amount adjustment area | region control part 11a Block extraction part 11b Complexity calculation part 11c Area size calculation part 12 Code amount control part 13 Encoding part 14 Code amount calculation part

Claims (6)

An encoding device that divides an input image into a plurality of partial areas and encodes the partial areas with a predetermined code amount,
A size determining means for determining a size of each of the partial regions, with a region corresponding to an allowable encoding delay time as a maximum value;
Code amount assigning means for assigning the code amount according to the size of the partial area determined by the size determining means;
Encoding means for encoding the partial area whose size is determined by the size determination means with the code amount allocated by the code amount allocation means;
An encoding device comprising:   The encoding apparatus according to claim 1, wherein the size determining unit determines each size of the partial area according to the complexity according to the complexity of the image included in the partial area. .   The size determining means calculates a variance value of an image value included in the partial area as the complexity, and determines each size of the partial area based on the calculated variance value. 2. The encoding device according to 2.   The encoding apparatus according to claim 1, wherein the encoding unit encodes the input image in a screen order. An encoding method suitable for dividing an inputted input image into a plurality of partial areas and encoding the partial areas with a predetermined code amount,
A size determining step for determining a size of each of the partial regions, with a region corresponding to an allowable encoding delay time as a maximum value;
A code amount assigning step for assigning the code amount in accordance with the size of the partial area determined by the size determining step;
An encoding step of encoding the partial area whose size is determined by the size determination step with the code amount allocated by the code amount allocation step;
The encoding method characterized by including. An encoding program for causing a computer to divide an inputted input image into a plurality of partial areas and to encode the partial areas with a predetermined code amount,
A size determination procedure for determining the size of each of the partial regions, with a region corresponding to an allowable encoding delay time as a maximum value;
A code amount allocation procedure for allocating the code amount in accordance with the size of the partial area determined by the size determination procedure;
An encoding procedure for encoding the partial area whose size is determined by the size determination procedure with the code amount allocated by the code amount allocation procedure;
An encoding program for causing a computer to execute.

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