JP2006203744A - Still image generating apparatus and still image generation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a still image generating apparatus which generates an image signal for preliminarily performing down-sampling of an image part to be specified as a low resolution region, and to perform JPEG coding on other regions as still images, with resolution as is, with high efficiency. <P>SOLUTION: A still image to be inputted is divided into macro blocks by a division part 11, the resolution for each region is specified by a resolution specifying part 13, downsampling of the image to be specified as low resolution is performed by a downsampling part 12, to obtain a block image and an image at a black level. The macro block image in the region specified as high resolution region, the block image of the low-resolution region, and the image at the black level are rearranged so as to skip the image at the black level by a rearrangement part 14, and the obtained image is coded by a JPEG coder 2. The still image generating apparatus 1 is realized, by adding rearrangement information by an information addition part 17, after a coded signal to which JPEG coding has been applied. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a still image generating apparatus and a still image generating method for performing processing for generating an image whose resolution is set for each region into a compressed encoded signal compressed with high encoding efficiency.

  Recently, an image device using a JPEG (Joint Photographic Coding Experts Group) method for compressing and encoding an image signal has been commercialized. For example, a DV digital video camera encodes and records a moving image captured by the camera using an intra method, so-called “motion JPEG”. Since the recorded signal can be decoded from an arbitrary frame image, it is possible to perform editing by designating an arbitrary frame and connecting moving images.

  On the other hand, many surveillance camera apparatuses for ensuring the safety of the region have been introduced. It has become easier to find the criminal based on the images taken by the surveillance camera. On the other hand, since an image related to personal life captured by a surveillance camera is a violation of privacy, the image of an area related to an individual is set at a low resolution. If the image portion set to low resolution can be encoded with a high compression rate, the image taken by the surveillance camera can be transmitted at a low communication speed when transmitted using a communication line, and the recording area of the medium for recording the image can be reduced. It is preferable because it can be reduced.

Patent Document 1 discloses an image compression / decompression method in which encoding is performed using a general-purpose quantization table as a quantization table used when compressing and decompressing images having different image quality for each region. . That is, the input image is divided into a plurality of areas, and at least one of the plurality of areas constituting the image is downsampled according to the image quality required for the area, and downsampled to at least a part of the area. For example, black-level image data is inserted in other area portions (hereinafter also referred to as fill bits). The downsampled image and black level image data are quantized using a common quantization table and encoded. Decoding of an encoded image is performed by inverse quantization using a quantization table used at the time of encoding, and interpolating pixels in a downsampled region among a plurality of regions constituting the inversely quantized image. By performing upsampling, an image having a required image quality is output for each area. The input image is down-sampled to reduce the resolution, and fill-bit single color black data is input to the compression encoder, that is, image data with a reduced amount of information is input to the compression encoder. Since it is input, it is expected that encoded data with a high compression rate will be output.
JP 2004-222218 A

However, when the image compression method disclosed in Patent Document 1 is encoded using, for example, JPEG, an encoded output with a high compression rate according to the amount of information included in the input image data cannot be obtained. Although the entropy of the fill-bit image data having a single luminance level is 0, the encoded data obtained by encoding the fill-bit portion exists as a predetermined amount of data. The amount of data does not become a predetermined amount or less by encoding.
That is, downsampled image data that is not thinned by data thinning, replacement image data that has been thinned by data thinning and then replaced with a single luminance level, and other image data having a normal resolution, for example, High-efficiency compression encoding cannot be performed by an encoding method such as JPEG.

  Therefore, the present invention has been made to solve the above-described problems. Image data obtained by down-sampling by data thinning and other image data having a normal resolution are subjected to orthogonal transformation, quantum And a still image generation apparatus and a still image generation method for generating a still image signal for performing compression encoding with high efficiency by an encoding method performed by taking a difference between DC components of adjacent regions. With the goal.

According to a first aspect of the present invention, there is provided a still image generating apparatus that obtains a compressed compressed still image having a smaller amount of information than the still image from an input still image, and a dividing unit that divides the still image into a matrix. A resolution determining unit that determines a resolution for each region divided in a matrix by the dividing unit, and a still image of each region is downloaded according to the resolution for each region determined by the resolution determining unit. A down-sampling unit that samples and generates a matrix image region having a thinned region and a non-thinned region arranged in a matrix, and determines an image that has not been thinned in the thinned region in advance as the thinned region The four sample areas are collected as a first sample image, and the thinned image is collected in a region other than the first sample image collected to obtain a second sample. When the image arrangement unit used as an image and the image of the non-decimated area are set as the third sample image, the matrix image area is sequentially scanned in the horizontal direction to extract a plurality of address information of the first and third sample images. An address extraction unit, a calculation unit that calculates a difference between adjacent address information extracted by the address extraction unit, and the first and third sample images, and the difference corresponding to the first and third sample images And a control unit that stores the data in a storage unit.
According to a second aspect of the present invention, there is provided a still image generating apparatus that obtains a compressed compressed still image having a smaller amount of information than the still image from an input still image, a dividing unit that divides the still image into a matrix, and the division A resolution determining unit that determines a resolution for each region divided in a matrix form in a unit, and down-sampling still images in each region according to the resolution for each region determined by the resolution determining unit A downsampling unit for generating a matrix image area having a thinned area and a non-thinned area arranged in a matrix, and images that have not been thinned in the thinned area are defined at four predetermined corners of the thinned area An image collected in a region as a first sample image, and the thinned image is collected in a region other than the region where the first sample image is collected as a second sample image. When the image of the row portion and the non-decimated area is the third sample image, the second sample image is skipped by sequentially scanning the matrix image area in the horizontal direction while skipping the second sample image. And a control unit for storing the number of the skipped second sample images together with the first and third sample images in the storage unit in association with the first and third sample images, Provided is a still image generating apparatus including the above-described feature.
According to a third aspect of the present invention, in the still image generation method for obtaining a compressed compressed still image having a smaller amount of information than the still image from the input still image, the still image is divided into a matrix and each divided The resolution is determined for each area, and the still image of each area is down-sampled according to the resolution for each area to generate a matrix image area having a thinned area and a thinned area arranged in a matrix. Then, the images that are not thinned out in the thinned-out region are collected in the predetermined four corner regions of the thinned-out region as the first sample image, and the thinned image is collected in the first sampled image. When the second sample image is collected in a region other than the region and the image of the non-decimated region is the third sample image, the matrix image region is sequentially scanned in the horizontal direction, A plurality of address information of the first and third sample images are extracted, a difference between adjacent ones of the plurality of address information is calculated, and the difference is associated with the first and third sample images together with the first and third sample images. And a still image generation method characterized in that the image is stored in a storage unit.
According to a fourth aspect of the present invention, in the still image generation method for obtaining a compressed compressed still image having a smaller amount of information than the still image from the input still image, the still image is divided into a matrix, and each divided The resolution is determined for each area, and the still image of each area is down-sampled according to the resolution for each area to generate a matrix image area having a thinned area and a thinned area arranged in a matrix. Then, the images that are not thinned out in the thinned-out region are collected in the predetermined four corner regions of the thinned-out region as the first sample image, and the thinned image is collected in the first sampled image. When the second sample image is collected in a region other than the second sample image and the image of the non-decimated region is used as the third sample image, the matrix is skipped while skipping the second sample image. The image area is sequentially scanned in the horizontal direction, the number of the second sample images skipped is counted, and the number of the second sample images skipped together with the first and third sample images is counted as the first, There is provided a still image generation method characterized by storing in a storage unit in correspondence with three sample images.

According to the present invention, the still image is divided into a matrix, the resolution is determined for each area divided into the matrix, and the still image of each area is determined according to the determined resolution for each area. Down-sampling to generate a matrix image area having a thinned area and a non-thinned area arranged in a matrix, and images that have not been thinned in the thinned area are defined at four predetermined corners of the thinned area. A first sample image is collected in a region, the thinned image is collected in a region other than the first sample image is collected as a second sample image, and an image in the non-decimated region is a third sample image. The matrix image area is sequentially scanned in the horizontal direction to extract a plurality of address information of the first and third sample images, and adjacent to the plurality of extracted address information. Since there is a special configuration in which the difference between the first and third sample images is stored in the storage unit in association with the first and third sample images, it is obtained by downsampling by data thinning. The image data and other image data having a normal resolution are subjected to high-efficiency compression coding by an orthogonal transformation, quantization, and a coding method that takes the difference of the DC component of each adjacent region. Still image generating apparatus and still image generating method for generating a still image signal can be realized.
Further, according to the present invention, after dividing the still image into a matrix, the resolution is determined for each divided region, and the still image of each region is down-sampled according to the resolution of each region. Generating a matrix image area having a thinned area and a thinned area arranged in a matrix, and collecting images not thinned in the thinned area in predetermined four corner areas of the thinned area. A first sample image, the thinned image is collected in a region other than the first sample image collected as a second sample image, and the non-decimated region image is a third sample image, The matrix image area is sequentially scanned in the horizontal direction while skipping the second sample image, and the number of skipped second sample images is counted. Since there is a special configuration in which the number of the skipped second sample images together with the three sample images is stored in the storage unit corresponding to the first and third sample images, an image obtained by down-sampling by data thinning Still image for high-efficiency compression coding of data and other image data having normal resolution by orthogonal transformation, quantization, and a coding method that takes the difference of the DC component of each adjacent region A still image generating apparatus and a still image generating method for generating a signal can be realized.

Hereinafter, still image generation apparatuses and still image generation methods according to embodiments of the present invention will be described with reference to FIGS.
FIG. 1 is a block diagram illustrating a configuration example of a still image encoding / decoding system according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating an operation example of the resolution designation unit of the still image generation device according to the embodiment of the present invention.
FIG. 3 is a diagram illustrating an operation example of the downsampling unit of the still image generating apparatus according to the embodiment of the present invention.
FIG. 4 is a diagram illustrating an operation example of the downsampling unit according to the embodiment of the present invention.
FIG. 5 is a diagram illustrating an operation example of encoding a down-sampled image.
FIG. 6 is a diagram illustrating an operation example of the rearrangement unit according to the embodiment of the present invention.
FIG. 7 is a diagram illustrating an operation example of the rearrangement unit according to the embodiment of the present invention.
FIG. 8 is a diagram showing a modification of the operation of the rearrangement unit according to the embodiment of the present invention.
FIG. 9 is a diagram illustrating an operation example of the information adding unit according to the embodiment of the present invention.
FIG. 10 is a diagram showing a modified example of the operation of the rearrangement unit according to the embodiment of the present invention.
FIG. 11 is a diagram showing another modification example of the rearranging unit operation according to the embodiment of the present invention.


FIG. 12 is a flowchart illustrating an operation example of the still image generation apparatus according to the embodiment of the present invention.
FIG. 13 is a flowchart illustrating an operation example of the decoding apparatus according to the embodiment of the present invention.
FIG. 14 is a flowchart showing a modification of the operation of the decoding apparatus according to the embodiment of the present invention.
FIG. 15 is a flowchart showing another modification of the operation of the decoding apparatus according to the embodiment of the present invention.
FIG. 16 is a block diagram illustrating a modified configuration example of a still image generation, encoding, and decoding apparatus according to an embodiment of the present invention.

  The still image generation device performs orthogonal transformation, quantization, and difference of DC components of adjacent areas on image data obtained by down-sampling by data thinning and other image data having normal resolution. The purpose of generating a still image signal for performing compression coding with high efficiency by the encoding method to be performed is to divide the still image into a matrix and determine the resolution for each area divided into the matrix, According to the determined resolution for each area, the still image of each area is downsampled to generate a matrix image area having a thinned area and a thinned area arranged in a matrix, and the thinned area is present. The images that are not thinned out in the region are collected in the predetermined four corner regions of the thinned-out region as a first sample image, and the thinned-out image is the first sample image. When the sample image is collected in an area other than the collected area as the second sample image, and the image in the non-decimated area is set as the third sample image, the matrix image area is sequentially scanned in the horizontal direction, and the first, A plurality of address information of three sample images are extracted, a difference between adjacent ones of the extracted plurality of address information is calculated, and the difference is associated with the first and third sample images together with the first and third sample images. Realized by storing in the storage unit.

The configuration of the still image generation apparatus will be described together with the configuration of the still image encoding / decoding system.
The still image encoding / decoding system shown in FIG. 1 includes a still image generating apparatus 1 including a dividing unit 11, a downsampling unit 12, a resolution specifying unit 13, a rearranging unit 14, and an information adding unit 17, and a JPEG (Joint Photographic). Coding Experts Group) encoding device 2 and still image decoding device 3 including information extraction unit 31, JPEG decoding unit 32, rearrangement restoration unit 33, position determination unit 34, and interpolation processing unit 35. The still image generating device 1 and the still image decoding device 3 are connected by a communication line.
16 includes an input device 1001, a resolution specifying unit 1002, a central processing control device 1003, an external storage device 1004, a temporary storage device 1005, a communication device 1006, and an output device. 1007.

The operation of the still image generation device will be described.
A still image encoding / decoding system will be described with reference to FIG.
First, the resolution setting for an image input from a surveillance camera or the like is made via the resolution designation unit 13. For example, a region where a space where an individual lives is photographed is set to a low resolution, and a region requiring monitoring is set to a high resolution. The resolution of the image is set for each macroblock of 16 pixels × 16 pixels in the monitoring image.

  For example, image data of one frame of 640 pixels × 480 pixels photographed by the surveillance camera is input to the dividing unit 11 and divided into images of macroblocks of 16 pixels × 16 pixels. The divided image is down-sampled according to the resolution designated by the resolution designation unit 13. That is, the macroblock in the area designated as the high resolution area remains 16 pixels × 16 pixels, and the macroblock in the area designated as the low resolution area is thinned out into 8 pixels × 8 pixels data.

In the rearrangement unit 14, the image data that has not been thinned out is collected at the upper left position of the macro block to be 8 pixel × 8 pixel block data, and the thinned data is placed at other positions in the macro block. After being collected, for example, it is replaced with black image data having a luminance level of 0.
The rearrangement unit 14 rearranges the image data of the blocks that have not been thinned out, the image data composed of four blocks of the macro block area designated as the high resolution area, and the black image data into separate areas. It is done.
The JPEG encoding device 2 receives image data of blocks that have not been thinned out and image data that is composed of four blocks of a macro block area designated as a high resolution area, and is encoded by the JPEG method. A compressed encoded signal is obtained.

Here, image data of a macroblock in which image data of a block that has been downsampled by the downsampling unit 12 and has not been thinned out and black image data of a block that has been thinned out and replaced with black are arranged adjacent to each other. Is encoded, the difference in the luminance level between the blocks is large, so the decrease in the code amount after JPEG compression is small. Despite reducing the entropy of the image by replacing the thinned image data with black single color data, the amount of information in the compressed encoded signal does not become a small value corresponding to the decrease in entropy. It is.
In contrast, in the case of an image in which the luminance level difference between adjacent blocks is reduced by rearranging the image data block and the black image data block in the rearrangement unit 14, the compression encoded signal obtained by encoding As for the code amount, a compressed encoded signal having a small code amount can be obtained in accordance with a decrease in entropy of an image.

The compressed encoded signal output from the JPEG encoding apparatus 2 and the order data indicating the order of the blocks rearranged by the rearrangement unit 14 are input to the information addition unit 17. The compressed encoded signal and the sequence data are time-axis multiplexed to generate an encoded information signal.
An encoded information signal is output from the still image generation device 1.

The output encoded information signal is input to a still image decoding device 3 disposed at a remote place via a communication line, where the image signal is decoded.
The still image decoding device 3 will be described.

In the information extraction unit 31, the input encoded information signal is separated into a compressed encoded signal and a sequence data. The JPEG decoding unit 32 performs JPEG decoding of the compressed encoded signal. Image data of blocks not thinned out and image data composed of four blocks of a macro block area designated as a high resolution area are obtained. The rearrangement / restoration unit 33 rearranges the image block data obtained by decoding based on the rearrangement order data obtained by the information extraction unit 31. When output from the downsampling unit 12, image data having the same block arrangement is obtained. The position determination unit 34 determines the position of the macro block designated as the low resolution area. In the interpolation processing unit 35, the upper left 8 pixel × 8 pixel block data of the macro block designated as the low resolution region is generated as macro block data interpolated to 16 pixels × 16 pixels by upsampling. The image data of the macro block designated as the high resolution area is output as it is. The image data generated by the interpolation processing unit 35 is supplied to a monitor TV (not shown) and displayed there.
Here, it has been described that the JPEG decoding unit 32 is built in the still image decoding device 3. The JPEG decoding unit 32 may use a JPEG decoding device externally attached to the still image decoding device 3.

The resolution designation unit 13 will be described with reference to FIG.
Here, in order to simplify the description, the case where the image data is 64 pixels × 64 pixels will be described.
In the figure, image data of 64 × 64 pixels is arranged as image data of four macroblocks in each of horizontal and vertical. Here, the macroblock to which halftone dots are attached is an area designated as a low resolution area.

  FIG. 3 shows the positional relationship between macroblock image data arranged in 16 pixels in the horizontal (x) direction and 16 pixels in the vertical (y) direction, and image data of four blocks. Let δs be the image data of a block arranged as 0 to 7 pixels in the x direction and 0 to 7 pixels in the y direction. Similarly, let αs, βs, and γs be the image data of the other three blocks shown in FIG.

The downsampling unit 12 and the rearrangement unit 14 will be described with reference to FIG.
The macro block at the upper left shown in the figure is designated as a low resolution area by the resolution designation unit 13. The downsampling unit 12 thins out the pixel data of 1, 3, 5,..., 15 in the x direction out of the macroblock image data of 16 pixels × 16 pixels, and 0, 2, 4, ..., 14 pixel data remain without being thinned out. Therefore, the pixel data of 0, 2, 4,..., 14 are collected in the area of the block of δs.
Similarly, thinning is performed in the y direction, and data not thinned out is collected in δs.

The thinned data is collected in the block area of αs, βs, and γs. The image data of αs to γs is unnecessary data. In order to reduce the entropy of the image data, unnecessary image data of αs to γs is replaced with single color data. The data to be replaced is, for example, black image data having a luminance level of 0 in order to distinguish it from the data of δs. It may be replaced with data of maximum luminance or gray data of intermediate luminance. However, it is necessary to exclude the value data used for replacement from the data indicating the brightness level of δs. When gray data is used, care must be taken because the gradation at that luminance level at δs is reduced by one bit.
Note that a downsampled output signal with less distortion can be obtained by using a low-pass filter for removing the aliasing distortion caused by downsampling at the input of the downsampling unit 12.

The JPEG encoding device 2 will be described with reference to FIG.
A case will be described in which the top block of the image shown in (a) of the figure is directly input to the JPEG encoding apparatus 2 for encoding. This is an example in which the rearrangement unit 14 does not rearrange the image data.
In the JPEG encoding apparatus 2, image data for each block of 8 pixels × 8 pixels is subjected to discrete cosine transform to obtain frequency data. Of the frequency data, the AC component is quantized by a predetermined quantization table, and the DC component is DPCM (differential pulse code modulation) for each block to generate a compressed encoded signal. (B) shows the DC level in that case, and the change of the direct current level in the low resolution region is large. The portion indicates that there is little reduction in the amount of code obtained by compression encoding despite encoding low-resolution image data.
Therefore, the rearrangement unit 14 rearranges data so that the JPEG encoding apparatus 2 can obtain a high compression rate.

The rearrangement unit 14 will be described with reference to FIG.
The rearrangement unit 14 configures αs to γs black image data blocks of a portion designated as a low resolution region, δs blocks of a portion designated as a low resolution region, and αs constituting a macro block of a high resolution region. The four blocks of ~ δs are separated. When sequentially scanning the blocks in the scanning line direction, the black image data blocks are skipped and scanned. The image data (c) shown in the figure is scanned to obtain the image data (d). Since the DC component obtained by performing discrete cosine transform on the image data (d) does not change greatly, the JPEG encoding device 2 encodes the image data at a high compression rate.

With reference to FIG. 7, the order data generated by the rearrangement unit 14 will be described.
In the figure, when scanning a block, scanning is performed while skipping blocks of black image data, and the number of skipped blocks is counted. After temporarily storing the number of skipped blocks, the stored count number is supplied to the rearrangement restoring unit 33 as rearrangement order data. The rearrangement restoration unit 33 and the position determination unit 34 specify and determine the location of the skipped black image data block.

With reference to FIG. 8, a modified example of the order data generated by the rearrangement unit 14 will be described.
Each block is assigned a series of numbers in the order of scanning, and the address value of the block that is input to the JPEG encoding apparatus 2 and encoded is stored. Next, the difference between the stored address values is calculated. The address value of the block to be encoded is 0, 2, 3, 4, 6, 10, 11,..., And the difference value is 1, 2, 1, 1, 2, 4, 1,.・ ・.
Either the arrangement order data shown in FIG. 7 or the arrangement order data shown in FIG. 8 may be used.

The information adding unit 17 will be described with reference to FIG.
In FIG. 7, the encoded information signal is shown in FIG. 7 or FIG. 8 following the SOI (Start of Image), header, image data, and EOI (End of Image) generated by the JPEG encoding apparatus 2. Arrangement order data is configured to be added to the information addition position as additional information. Here, the black image data is not input to the JPEG encoding device 2 and is not included in the compressed encoded signal.

  Here, the code amount of the encoded information signal shown in FIG. 9 and the data amount when encoding including black image data will be described. Even when the entire block is a single-color black image, a JDC encoding inserts a DC component difference value and an EOB (End of Block) code into the compressed encoded signal for each image constituting the block. . Although the AC component is 0, the code amount of the compressed signal is not less than a predetermined value because of the code that is fixedly required. On the other hand, when the arrangement order data is output as additional data, a small code amount is sufficient as described above.

  Therefore, rather than the image data shown in FIG. 4 directly encoded by the JPEG encoding device 2, the compressed encoded signal obtained by encoding the image data shown in FIG. 6D by the JPEG encoding device 2 is used. The encoded information signal in which the order data is added as additional information is obtained as a signal with a smaller code amount.

With reference to FIG. 10, a first modification of the block scan order will be described.
The scanning order of the blocks in FIG. 10 is compared with the scanning in the scanning line direction of FIG. 6C. FIG. 10 scans the macroblocks in the scanning line order after scanning the macroblocks in the scanning line order. is doing. In this case, it is considered that the luminance signal levels of blocks adjacent in the vertical and horizontal directions encoded by the JPEG encoding device 2 are similar values when encoding a natural image. The DC signal level is reduced, and the encoding efficiency of the compressed encoded signal is improved.

With reference to FIG. 11, a second modification of the block scan order will be described.
In this figure, the image data of 32 pixels × 32 pixels is used as a super macro block, and after the block data in the super macro block is scanned in the scanning line direction, the super macro block data is encoded in the scanning line order. is there.
Which of the scanning methods shown in FIGS. 6, 10, or 11 should be used depends on the position pattern designated by the resolution designation unit 13 or the one suitable for the shape of the subject. And use it.

With reference to FIG. 12, the signal flow of the still image generating apparatus will be described.
First, image data is acquired by the dividing unit 11 in S (step) 101. The image data acquired in S102 is divided into data for each macroblock of 16 pixels × 16 pixels. In S103, macro block position information of a preset low resolution area is obtained. In S104, it is determined whether each macroblock is a macroblock whose resolution is lowered or a macroblock whose resolution is not lowered. In the case of a macroblock designated as a low resolution area, downsampling is performed in S105. The thinned image data is replaced with black image data. The position information of the macroblock down-sampled in S106 is stored.

In step S107, one block obtained by downsampling and four blocks not subjected to downsampling are continuously scanned in a predetermined order, and black image data encoded by JPEG is excluded. Image data can be obtained. Arrangement order data is obtained in S108, and the data is temporarily stored. The image data from which the black image data is removed in S109 is JPEG encoded. After the EOI of the compressed encoded signal obtained by JPEG encoding in S110, the sequence data or the encoded data excluding the redundancy of the sequence data is added as control information. An encoded information signal is obtained. The generation of the encoded information signal of the image for one frame is completed.
In addition, when encoding the frame image output from the surveillance camera continuously, the operations of S101 to S110 are repeated.

The signal flow of the decoding apparatus will be described with reference to FIG.
First, in S201, an encoded information signal generated by the still image generation device and transmitted via a communication line by a bit stream is acquired. In S202, the compressed encoded signal and the order data are acquired from the encoded information signal. The compressed encoded signal is decoded by the JPEG decoding unit 32. In step S204, block arrangement information is obtained based on the arrangement order data. If it is detected in S205 that the block is a downsampled block, the interpolation processing unit 35 performs upsampling and obtains macroblock image data. A decoded image signal is obtained based on the image data of the macroblock that is not downsampled by the JPEG decoding unit 32 and the upsampled image data. The decoding process of image data for one still image is completed.

With reference to FIG. 14, a signal flow in a modification of the decoding apparatus will be described. Hereinafter, the same functions as those in FIG. 13 are denoted by the same reference numerals and description thereof is omitted.
In the signal flow shown in FIG. 14, the order of S203 and S204 is reversed compared to the signal flow shown in FIG. That is, after the arrangement order data is obtained first, the compressed encoded signal is decoded. The method shown in FIG. 14 can perform the same decoding process as the method shown in FIG.

With reference to FIG. 15, the flow of signals in another modification of the decoding apparatus will be described.
The signal flow shown in FIG. 15 is different from the signal flow shown in FIG. 13 in that the operation of S204 is performed after S206. The same decoding process as that shown in FIG. 13 is performed by the method shown in FIG.

With reference to FIG. 16, a still image generation, encoding, and decoding apparatus will be described.
The central processing control apparatus 1003 of the still image generation, encoding, and decoding apparatus 1000 includes a dividing unit, a downsampling unit, a rearranging unit, a JPEG encoding unit, an information adding unit, an interpolating unit, a determining unit, and a rearranging unit. A computer program for executing the restoring means, the JPEG decoding means, and the information extracting means is loaded. That is, the still image generation, encoding, and decoding device is configured in the same manner as a so-called computer, and the functions of the still image generation device 1, the JPEG encoding device 2, and the still image decoding device 3 shown in FIG. It can be executed by one device.

  As described above, according to the still image generation apparatus in the still image encoding / decoding system shown in the embodiment, the still image is divided into a matrix by the dividing unit 11, and each region divided into the matrix is divided. The resolution is determined by the resolution specifying unit 13, and the still image of each region is downsampled by the downsampling unit 12 according to the determined resolution for each region, and the thinned region and the thinned region arranged in a matrix form A matrix image region having a region is generated, and images not thinned out in the thinned region are collected by the rearrangement unit 14 in predetermined four corner regions of the thinned region and used as the first sample image. When the image is collected in an area other than the area where the first sample image is collected to form the second sample image, and the image in the non-decimated area is used as the third sample image, a matrix image The area is sequentially scanned in the horizontal direction, a plurality of address information of the first and third sample images are extracted, a difference between adjacent ones of the extracted plurality of address information is calculated, and the difference is calculated together with the first and third sample images. Since there is a configuration in which the first and third sample images are stored in the storage unit, the image data obtained by down-sampling output from the still image generating device and other image data having normal resolution A JPEG encoding device 2 performs orthogonal transformation, quantization, and encoding that takes the difference of the DC component of each adjacent region, and can perform decoding by performing compression encoding suitably with high efficiency An encoding / decoding system can be realized.

  For example, the present invention can be applied to an encoding apparatus that sets the resolution in advance, and efficiently encodes an image signal of a surveillance camera, for example.

It is a block diagram which shows the structural example of the still image encoding and decoding system which concerns on implementation of this invention. It is the figure which showed the operation example of the resolution designation | designated part of the still image generation device which concerns on implementation of this invention. It is the figure which showed the operation example of the downsampling part of the still picture production | generation apparatus which concerns on implementation of this invention. It is the figure which showed the operation example of the downsampling part which concerns on implementation of this invention. It is the figure which showed the operation example of the encoding of the downsampled image. It is the figure which showed the operation example of the rearrangement part which concerns on implementation of this invention. It is the figure which showed the operation example of the rearrangement part which concerns on implementation of this invention. It is the figure which showed the modification of operation | movement of the rearrangement part which concerns on implementation of this invention. It is the figure which showed the operation example of the information addition part which concerns on implementation of this invention. It is the figure which showed the modification of operation | movement of the rearrangement part which concerns on implementation of this invention. It is the figure which showed the other modification of the rearrangement part operation | movement which concerns on implementation of this invention. It is the figure which showed the operation example of the still image production | generation apparatus which concerns on implementation of this invention with the flowchart. It is the figure which showed the example of operation | movement of the decoding apparatus based on implementation of this invention with the flowchart. It is the figure which showed the modification of the operation | movement of the decoding apparatus which concerns on implementation of this invention with the flowchart. It is the figure which showed the other modification of the decoding apparatus operation | movement which concerns on implementation of this invention with the flowchart. It is a block diagram which shows the modification structural example of the still image production | generation, encoding, and decoding apparatus which concerns on implementation of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Still image production | generation apparatus 2 JPEG encoding apparatus 3 Still image decoding apparatus 11 Division | segmentation part 12 Downsampling part 13 Resolution designation | designated part 14 Rearrangement part 17 Information addition part 31 Information extraction part 32 JPEG decoding part 33 Rearrangement restoration part 34 Position Determination unit 35 Interpolation processing unit 1000 Still image generation, encoding, and decoding device 1001 Input device 1002 Resolution specifying unit 1003 Central processing control device 1004 External storage device 1005 Temporary storage device 1006 Communication device 1007 Output device

Claims (4)

In a still image generating device that obtains a compressed compressed still image having a smaller amount of information than the still image from an input still image,
A dividing unit for dividing the still image into a matrix;
A resolution determining unit for determining a resolution for each region divided in a matrix by the dividing unit;
In accordance with the resolution for each area determined by the resolution determination unit, the still image of each area is down-sampled to generate a matrix image area having a thinned area and a thinned area arranged in a matrix. A downsampling unit to
The images that are not thinned out in the thinned-out area are collected in the four corner areas determined in advance in the thinned-out area as the first sample image, and the thinned image is collected other than the first sample image collected. An image arrangement unit that is collected in the region and used as a second sample image;
An address extraction unit that sequentially scans the matrix image region in the horizontal direction and extracts a plurality of pieces of address information of the first and third sample images when the image of the non-decimation region is a third sample image;
A calculation unit that calculates a difference between adjacent address information extracted by the address extraction unit;
A control unit that stores the difference together with the first and third sample images in the storage unit in association with the first and third sample images;
A still image generating apparatus comprising: In a still image generating device that obtains a compressed compressed still image having a smaller amount of information than the still image from an input still image,
A dividing unit for dividing the still image into a matrix;
A resolution determining unit for determining a resolution for each region divided in a matrix by the dividing unit;
In accordance with the resolution for each area determined by the resolution determination unit, the still image of each area is down-sampled to generate a matrix image area having a thinned area and a thinned area arranged in a matrix. A downsampling unit to
The images that are not thinned out in the thinned-out area are collected in the four corner areas determined in advance in the thinned-out area as the first sample image, and the thinned image is collected other than the first sample image collected. An image arrangement unit that is collected in the region and used as a second sample image;
When the image of the non-decimation area is the third sample image, the matrix image area is sequentially scanned in the horizontal direction while skipping the second sample image, and the number of skipped second sample images is counted. A counting unit to
A control unit that stores the number of the skipped second sample images together with the first and third sample images in a storage unit in association with the first and third sample images;
A still image generating apparatus comprising: In a still image generation method for obtaining a compressed compressed still image having a smaller amount of information than the still image from an input still image,
After dividing the still image into a matrix, determine the resolution for each divided area,
In accordance with the resolution for each area, down-sampling the still image of each area to generate a matrix image area having a thinned area and a thinned area arranged in a matrix,
The images that are not thinned out in the thinned-out area are collected in the four corner areas determined in advance in the thinned-out area as the first sample image, and the thinned image is collected other than the first sample image collected. To the second sample image,
When the image of the non-decimation area is a third sample image, the matrix image area is sequentially scanned in the horizontal direction, and a plurality of address information of the first and third sample images are extracted,
Calculate the difference between adjacent addresses of the plurality of address information,
The still image generation method, wherein the difference is stored in the storage unit in association with the first and third sample images together with the first and third sample images. In a still image generation method for obtaining a compressed compressed still image having a smaller amount of information than the still image from an input still image,
After dividing the still image into a matrix, determine the resolution for each divided area,
In accordance with the resolution for each area, down-sampling the still image of each area to generate a matrix image area having a thinned area and a thinned area arranged in a matrix,
The images that are not thinned out in the thinned-out area are collected in the four corner areas determined in advance in the thinned-out area as the first sample image, and the thinned image is collected other than the first sample image collected. To the second sample image,
When the image of the non-decimation area is the third sample image, the matrix image area is sequentially scanned in the horizontal direction while skipping the second sample image, and the number of skipped second sample images is counted. And
A still image generating method, wherein the number of skipped second sample images together with the first and third sample images is stored in a storage unit in association with the first and third sample images.

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