JP2001339722A - Multi-channel image encoding apparatus, decode displaying apparatus, encoding method and decode displaying method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To encode, decode and display an image that is united into one stream from images of a plurality of video sources by time division multiplexing at a high efficiency and a low cost. SOLUTION: A digital image constructed by frames is converted into four sheets of secondary images sampled every other pixel both in a row and column in lossless. Two sheets (P1a, P1b) out of those four sheets of images, and two sheets (P2a, P2b) out of four sheets of secondary images generated relative to a frame of next time of the same image source are used to perform intra frames correlation, which is carried out by referring to frame correlation between the former 2 images and to the stronger correlation out of the frame correlations between each one sheet of the former image and the latter image. Further decoding and displaying of correlation between frames of this stream are performed to use all-purpose encoding/decoding device of that utilizes correlation between images, thus making it possible to enhance encoding efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for time-sharing one video channel having a data rate with a fixed value or an upper limit, such as a multi-camera video transmission device for monitoring and a time-lapse video recorder, by a plurality of video sources. The present invention relates to an image codec and an image recording / reproducing device used for the above.

[0002]

2. Description of the Related Art Conventionally, as a first multi-channel image encoding / decoding display device, Japanese Patent Laid-Open No. 10-34143 has been proposed.
No. 3 is known.

FIG. 10 shows a configuration of a conventional multi-channel image coding apparatus, in which a frame memory for temporarily storing an image sequence of all channels and only frames of the same video source are stored from the images stored therein. Is a re-ordering function of generating a GOP (Group of Picture) rearranged so as to be continuous. The inter-frame correlation in the GOP can be increased, and a GOP composed of only one video source frame is input to the inter-frame correlation encoder to improve the coding efficiency in the case of a multi-channel image. In the decoding, after performing inter-frame correlation decoding, frame rearrangement reverse to the encoding is performed.

[0004] Conventionally, as an image encoding device / decoding device applicable to the second multi-channel, ITU-T
Recommendation H.261 '93 / 3 Still image f
ormat, Sub-sampling pattern is applied to still image transmission using inter-frame correlation coding, that is, lossless sub-sampling of a frame into sub-sampling sub-pixels every other pixel in the vertical and horizontal directions. A method of performing inter-correlation coding is known.

FIG. 11 shows a selected pixel at the time of sub-sampling, and the number n (n = 0, 1, 1) of the 2 × 2 grid is shown.
By generating a total of four secondary images in which the number of pixels is 1/4 of the original image by extracting the pixels at the positions of (2, 3), the spatial correlation of adjacent pixels on the time axis It is intended to increase the coding efficiency of a still image by converting to inter-frame correlation and performing inter-frame correlation coding.

[0006]

However, in the above-mentioned first conventional multi-channel image encoding apparatus / decoding display apparatus, a large-capacity semiconductor frame memory (the number of video sources × the number of frames in a GOP) used for temporary storage is used. ) Is necessary and expensive, and the delay time due to the frame rearrangement is large (number of video sources × (number of frames in GOP−1) / frame rate).

In the conventional second multi-channel image encoding / decoding display device, since the correlation of the secondary image sequence is not strong for an image containing many high spatial frequency components, a high code There was a problem that the conversion efficiency could not be obtained.

The present invention has been made in order to solve such a problem. A digital image composed of frames is subjected to lossless conversion into four secondary images which are subsampled every other pixel in both the vertical and horizontal directions. 2 of the images
The spatial correlation between the former two images and the temporal correlation between each of the former two images are used by using the image and two of the four secondary images similarly generated for the frame of the same image source at the next time. Among them, the inter-frame correlation encoding is performed by referring to the stronger correlation, and the decoding is performed by performing the inverse transform of the encoding from the reference image thus generated and the difference information, so that the encoding efficiency is high and the number of the semiconductor frames is small. Memory is low cost, general-purpose codec (encoder / decoder) can be used, the frame rate between video sources is variable, and multi-screen split display can be easily realized on the display device during decoding display. An object of the present invention is to provide an excellent multi-channel image encoding method and apparatus, and a decoding display method and apparatus.

[0009]

According to the present invention, there is provided a multi-channel image coding apparatus and method, comprising: conversion means for converting a spatial correlation of an image into a time-axis correlation; a spatial correlation of the image and a time correlation of the image. And a coding unit that performs coding based on the selected inter-image correlation. The image has, for example, a frame structure or a field structure.

With this configuration, the spatial correlation between adjacent pixels of the original image can be treated as equivalent to the inter-image time correlation, and the stronger one of the spatial correlation and the temporal correlation is selected and coded. And a general-purpose encoder / decoder utilizing the correlation between images can be used.

In the multi-channel image encoding apparatus and method according to the present invention, the conversion means converts the digital image having the frame structure into four secondary images obtained by sub-sampling every vertical and horizontal pixel every other pixel. Means for extracting two first-frame secondary images from the converted first frame and two second-frame secondary images from a second frame indicating an image at a time subsequent to the first frame (2) A second image extracting unit, wherein the selecting unit determines a frame correlation between the first frame secondary image and a frame between each one of the first frame secondary image and the second frame secondary image. It is characterized in that a strong correlation is selected from among intercorrelations. Further, the digital image has a field structure.

According to this configuration, the stronger correlation is selected from the correlation within the same frame or the same field and the correlation between the frame or the field between the times, and the encoding is performed. A general-purpose encoder / decoder utilizing the above can be used.

A multi-channel image decoding display apparatus and method according to the present invention receives an image coded by the multi-channel image coding apparatus and method according to any one of claims 1 to 4 and 12 to 15. And decoding means for decoding the input image and decoding the image from difference information between the decoded image and the decoded image.

With this configuration, an image encoded by the spatial correlation and the time correlation of the image is input as an image encoded by an encoding method equivalent to the time correlation.
With a general-purpose decoder that decodes a time-correlated coded image, an image coded with respect to spatial correlation can also be decoded, and an image with low cost and high coding efficiency can be decoded.

Further, the multi-channel image encoding apparatus and method of the present invention subsamples images of a plurality of video sources at every other pixel in the vertical and horizontal directions, and converts four images subsampled from different video sources into a vertical and horizontal square. It is characterized by comprising secondary image forming means for forming a secondary image arranged and coding means for performing inter-image correlation coding of the secondary image. The image has, for example, a frame structure or a field structure.

With this configuration, the number of pixels in the vertical and horizontal directions of the secondary image matches the number of pixels in the original image. Therefore, a plurality of video sources are encoded by a general-purpose encoder corresponding to a video source having standard specifications. be able to.

The multi-channel image decoding display apparatus and method according to the present invention is described in claim 6, 7, 17 or 18.
Input means for inputting an image encoded by the multi-channel image encoding device and method described above, and decoding to the input image, and difference information between the decoded image and the decoded image. Decoding means for decoding an image.

With this configuration, an image encoded by the spatial correlation and the time correlation of the image is input as an image encoded by an encoding method equivalent to the time correlation.
A general-purpose decoder that decodes time-correlated coded images can decode images coded also for spatial correlation, and images from multiple video sources can be low-cost and highly coded. Can be decoded.

Further, the multi-channel image encoding apparatus and method according to the present invention include an assigning means for sub-sampling a plurality of image sources and setting the number of images to be assigned within a unit time for each image source, and encoding the images. Encoding means, and rate setting means for setting a transfer rate for each video source according to the number of images allocated in the unit time.

With this configuration, the number of subsampled images to be allocated within a unit time can be set to different values for each video source, and the frame rate after encoding can be set for each video source to be encoded. Encoding can be performed by changing the frame rate assigned to each video source while keeping the total frame rate constant.

Further, the multi-channel image decoding display apparatus and method of the present invention decodes a secondary image whose number of pixels is 1/4 of the original image, which is encoded by sub-sampling every other pixel in the vertical and horizontal directions. Decoding means, and display means for arranging the decoded secondary images in a vertical and horizontal square and displaying them as one screen divided into four.

With this configuration, four images of different video sources can be easily displayed on one screen only by arranging the decoded secondary images.

Further, in the multi-channel image decoding display apparatus and method according to the present invention, each of the decoded secondary images is converted into a vertical and horizontal number of pixels by a two-dimensional interpolation process, where n is an integer. 2 / n interpolation means, wherein the display means arranges the interpolated images in a vertical and horizontal square and performs n × n division display as one screen.

With this configuration, the interpolation processing is applied to the decoded secondary image, and only by arranging the secondary images, nx of different video sources can be obtained.
It is possible to easily display n images on one screen.

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 shows a first embodiment of a multi-channel image encoding method according to the present invention. In this embodiment, a case where the number of video sources is 16 will be described as an example.

In FIG. 1, SRC1 to SRC16 are:
One frame of each video source. spic1-spi
c16 is a reduced image obtained by dividing the pixels in each of the SRC1 to SRC16 frames into a 2 × 2 matrix and extracting only the pixel corresponding to the upper left position 1 by sampling. This reduced image is called a secondary image in the following description.

An image in which spic1 to spic4 are arranged in two rows and two columns vertically and horizontally and have the same number of pixels as the original frame is P1a. Similarly, the video sources 1 to 4 of the secondary images corresponding to the lower left 2, upper right 3, and lower right 4 pixel positions of the 2 × 2 matrix
P1b, P1c, P1d
It is. Similarly for SRC5 to SRC16,
A total of 16 images up to P1p are images generated from each one frame of 16 video sources.

Images generated in the same manner for the frames of the respective video sources at the next time are represented by P2a, P2
b, P2c, P2d,. . . , P2p.

The upper part of FIG. 3 shows a configuration diagram of the multi-channel image encoding device. As shown in FIG. 3, the multi-channel image encoding device includes a multiplexer 30, a frame synchronizer 31, a sub-sampling / reordering unit 32, a frame memory 33, and an inter-frame correlation encoder 34. The encoded video stream is transmitted or stored by a transmission path or an image storage 35.

Here, the multiplexer 30 multiplexes the video sources SRC1 to SRC into one stream, and the frame synchronizer 31 synchronizes the signals of all the video sources with frame pulses. The reordering unit 32 performs lossless sampling in every other pixel in the vertical and horizontal directions in a 2 × 2 matrix.
A secondary image is generated, and the secondary images are two-dimensionally arranged and their order is rearranged.
Is for temporarily storing a frame at the time of performing sampling of the sub-sampling / reordering unit 32, two-dimensional arrangement and order rearrangement, and an inter-frame correlation encoder 34 for performing encoding of a method such as MPEG2. It is.

FIG. 4 shows a reference relationship between pixels at the time of inter-frame correlation encoding. An arrow a indicates a reference to the same pixel position, and an arrow b indicates a reference to a pixel position different in both position and time.

The operation of the multi-channel image encoding method and apparatus configured as described above will be described with reference to FIGS. 1, 3 and 4 and FIG.

The video sources SRC1 to SRC16 are provided by a multiplexer 30 and a frame synchronizer 31.
The data is stored in the frame memory 33 via the sub-sampling / reordering unit 32 in units of frames synchronized with the frames between the video sources. The subsampling / reordering unit 32 inserts frames P2a and P2b at the next time after subsampling by a 2 × 2 matrix, a two-dimensional array of secondary images such as spic1 to spic4, and P1a and P1b. Similarly, the operation shown in FIG. 1 for inserting a frame at the next time in a skewered manner in units of two frames is generated by changing the reading order with a memory address given to the frame memory 33, and is input to the input of the interframe correlation encoder 34. give. The inter-frame correlation encoder 34 selects a frame having a strong correlation from the two referenceable frames shown in FIG. 4 and encodes a difference from the selected frame. Here, in FIG.
1b performs intra coding (I picture), and the following six frames perform forward prediction coding (P picture).

As described above, according to the embodiment of the present invention, a frame having a strong correlation between a subsampled image obtained by converting a spatial correlation into a time correlation and an image of the same video source at the next time. Since differential coding is performed using inter-correlation, the coding efficiency is higher than in the conventional example. In other words, the number of frames constituting the GOP required to obtain the same coding efficiency can be reduced as compared with the conventional example,
Lower cost. Further, the image input to the encoder is
In many cases, the frame has the same structure as the frame of the original video source that employs the standard signal system, so that there is an advantage that a general-purpose encoder LSI such as MPEG2 can be used.

Although the case of the inter-image correlation coding in the frame structure has been described so far, the present invention can be similarly applied to the field structure. At this time, the relationship between the reference pixels and the rearrangement order shown in FIG. 4 are changed as shown in FIG. 5, P1a and P2a are intra-coded (I pictures), and the subsequent six frames are forward-predicted-coded. (P picture). In FIG. 5, an arrow a indicates a reference to the same pixel position, and an arrow b indicates a reference to a pixel position different in both position and time. Arrow c indicates a reference to an adjacent pixel position.

(Embodiment 2) FIG. 6 shows a second embodiment of the multi-channel image encoding method according to the present invention. Also in the present embodiment, a case where the number of video sources is 16 will be described as an example.

In FIG. 6, SRC1 to SRC16 are:
One frame of each video source. spic1-spi
c16 is a reduced image obtained by dividing the pixels in each of the SRC1 to SRC16 frames into a 2 × 2 matrix and extracting only the pixel corresponding to the upper left position 1 by sampling. This reduced image is called a secondary image in the following description.

As in spic1, an image having 1/4 pixels from the original frame is P1a. Similarly, the composite images of the secondary images corresponding to the video sources 1 to 4 of the secondary images corresponding to the lower left 2, upper right 3, and lower right 4 of the pixel position of the 2 × 2 matrix are P1b, P1c, and P1d. SRC5-SR
Similarly, regarding C16, a total of 4 × 16 = 64 images are images generated from each frame of 16 video sources.

The images generated in the same manner for the frames of the respective video sources at the next time are P2a and P2a.
b, P2c, P2d,. . . , P2p.

The block diagram showing the configuration of the multi-channel image coding apparatus is the same as that in the first embodiment shown in FIG. In addition, the reference relationship between pixels at the time of inter-frame correlation encoding is the same as that in FIG. 4 shown in the first embodiment.

The operation of the multi-channel image coding method and apparatus configured as described above will be described with reference to FIGS. 6, 3 and 4. FIG. Video source SRC
The 1 to SRC 16 are stored by the multiplexer 30 and the frame synchronizer 31 in the frame memory 33 via the sub-sampling and reordering unit 32 in units of frames synchronized with the video source. The sub-sampling / reordering unit 32
Subsampling by 2 × 2 matrix, secondary image P
After 1a and P1b, the frames P2a and P2 at the next time
6 is generated by changing the reading order by the memory address given to the frame memory 33. The operation shown in FIG. Correlation encoder 3
4 to the input. The inter-frame correlation encoder 34
A frame having a strong correlation is selected from the two referenceable frames shown in FIG. 4 and a difference from the selected frame is encoded. In FIG. 4, P1a and P1b perform intra coding (I frame), and the subsequent six frames perform forward prediction coding (P frame).

As described above, according to the embodiment of the present invention, high coding efficiency, low delay, and low cost of the frame memory can be achieved as in the first embodiment. Further, there is an advantage that the configuration of the subsampling / reordering unit is simple and can be realized at low cost.

Although the case of the inter-image correlation coding in the frame structure has been described so far, it can be similarly performed in the field structure as in the first embodiment.

(Embodiment 3) A first embodiment of the multi-channel image decoding method of the present invention is shown in FIG. 2, and the case where the number of video sources is 16 will be described as an example as described above.

In FIG. 2, an image obtained by arranging losslessly sampled secondary images corresponding to the pixel positions of a 2 × 2 matrix with respect to video sources 1 to 4 in 2 rows and 2 columns is P
1a, P1b, P1c, and P1d. SRC5-SR
Similarly, for C16, a total of 16 images up to P1p are images constituting one frame of 16 video sources.

Similarly, P2a, P2b, P2c, P2
d,. . . , P2p.

The lower part of FIG. 3 shows a configuration diagram of the multi-channel image decoding device. As shown in FIG. 3, the multi-channel image decoding apparatus includes an inter-frame correlation image decoder 3
6. A video stream is input from a transmission path or an image storage 35 which has an inverse sub-sampling / reordering unit 37 and a frame memory 38 and transmits or stores an encoded video stream.

Here, the inter-frame correlation image decoder 36
Functions as an inverse transform of the inter-frame correlation encoder 34, the inverse subsampling / reordering unit 37 functions as an inverse transform of the subsampling / reordering unit 32, and a frame memory 38.
Is for temporarily storing a frame for the frame operation of the inverse subsampling / reordering unit 37.

The video stream decoded by the multi-channel image decoding device is output to a display 39,
An image is displayed on the display 39.

The operation of the multi-channel image decoding method and apparatus configured as described above will be described with reference to FIGS.

The intra-coded P 1 a and P 1 b are input to the inter-frame correlation image decoder 36, decoded, and stored in the frame memory 38. Thereafter, P2a, P2b, P1c, P1d, P2c,
The P2d is decoded from the decoded frame and the encoded difference information by the inter-frame correlation image decoder 36 as needed, and stored in the frame memory 38. By changing the reading order with the memory address given to the frame memory 38 by the inter-frame correlation image decoder 36, P1a, P1a
1b, P1c, P1d,. . . In this order, four pixels are synthesized by a 2 × 2 matrix by an operation exactly reverse to the subsampling at the time of encoding, and decoded SRC1 to SRC4 of each video source are generated. Similarly, SR
Decrypt C5 to SRC16.

As described above, according to the embodiment of the present invention, first, the same effect as in the first embodiment, that is, the subsampled image obtained by converting the spatial correlation into the time correlation and the same video source of the next time are obtained. Since differential coding is performed using the inter-frame correlation having a strong correlation with the image, the coding efficiency is higher than that of the conventional example. In other words, the number of frames forming a GOP required to obtain the same coding efficiency can be reduced as compared with the conventional example, resulting in low delay and low cost.
Furthermore, since the image input to the decoder often has the same structure as the frame of the original video source employing the standard signal system, a general-purpose decoder LS such as MPEG2 is used.
It has the advantage that I can be used.

Although the case of the inter-image correlation coding in the frame structure has been described so far, it can be similarly performed in the field structure as in the first embodiment.

(Embodiment 4) A second embodiment of the multi-channel image decoding method according to the present invention is shown in FIG. 7, and the case where the number of video sources is 16 will be described as an example.

In FIG. 7, the secondary images P1a, P1b, P1c and P1 are sampled losslessly with respect to the video sources 1 to 4 corresponding to the pixel positions of the 2 × 2 matrix.
d. Similarly, for SRC5 to SRC16, a total of 64 images constitute one frame of 16 video sources.

Similarly, P2a, P2b, P2c, P2
d,. . . , P2p.

The block diagram showing the configuration of the multi-channel image decoding apparatus is the same as that shown in the lower part of FIG. As shown in FIG. 3, the multi-channel image decoding apparatus includes an inter-frame correlation image decoder 36, an inverse sub-sampling / reordering unit 37, and a frame memory 38, and transmits or stores an encoded video stream. The video stream is input from the channel or the image storage 35, decoded, and output to the display 39.

Here, the inter-frame correlation image decoder 36
Functions as an inverse transform of the inter-frame correlation encoder 34, the inverse subsampling / reordering unit 37 functions as an inverse transform of the subsampling / reordering unit 32, and a frame memory 38.
Is for temporarily storing a frame for the frame operation of the inverse subsampling / reordering unit 37.

The display 39 inputs the decoded video stream and displays the video.

The operation of the multi-channel image decoding method and apparatus configured as described above will be described with reference to FIG. 7 and the lower part of FIG. Intra coded P
1a and P1b are input to the inter-frame correlation image decoder 36, decoded, and stored in the frame memory 38. Or later,
P2a, P2b, P1 encoded by forward prediction
c, P1d, P2c, and P2d are decoded from the decoded frame and the encoded difference information by the inter-frame correlation image decoder 36 as needed, and stored in the frame memory 38.

P1a, P1b, P1c, P1 are changed by the inter-frame correlation image decoder 36 changing the reading order with the memory address given to the frame memory 38.
d,. . . In the order of 2 × 2 matrix, four pixels are synthesized by the operation exactly reverse to the sub-sampling at the time of encoding, and the decoded SRC1 to SR
Generate C4. Similarly, decoding of SRC5 to SRC16 is performed.

As described above, according to the embodiment of the present invention, high coding efficiency, low delay, and low cost of the frame memory can be achieved as in the third embodiment. Further, there is an advantage that the configuration of the subsampling / reordering unit is simple and can be realized at low cost.

Although the case of the inter-image correlation coding in the frame structure has been described above, the embodiment can be similarly performed in the field structure as in the first embodiment.

(Embodiment 5) FIG. 8 shows a third embodiment of the multi-channel image coding method. In this embodiment, the sub-sampling / reordering unit 32 in FIG. 3 changes the weight of the frame rate for each video source.

The upper part 1) in FIG. 8 is a switching method in which 16 video sources equally divide the frame rate, and the switching method shown in the first and second embodiments corresponds to this.

FIG. 8 middle 2) shows seven video sources 1,
The frame rates of 2, 3, 11, 12, 13, 14 are
The case of sequentially assigning 4: 4: 4: 1: 1: 1: 1 is shown. In FIG. 3, when storing the image data in the frame memory 33 from the frame synchronizer 31 via the sub-sampling / reordering unit 32, only the seven video sources to be used are transferred. The generation of a secondary image sampled in a 2 × 2 matrix at every other pixel in the vertical and horizontal directions without loss is performed. The secondary images are two-dimensionally arranged and their order is rearranged. , 12, 1
Generates at a rate four times higher than 3,14.

The lower part 3) of FIG. 8 shows two video sources 1, 1
6 shows a case where the frame rates of 6 are sequentially allocated to 15: 1. In FIG. 3, when data is stored in the frame memory 33 from the frame synchronizer 31 via the sub-sampling / reordering unit 32, only two video sources to be used are transferred. The generation of a secondary image sampled in a 2 × 2 matrix form every other pixel in the vertical and horizontal directions in a lossless manner, the secondary images are arranged two-dimensionally and their order is rearranged. Generate at a rate.

The combination of the number of video channels and the frame rate is not limited to the three examples described above, and the multiplexer 30 dynamically selects the video source and sets the frame rate every time the multiplexer 30 makes a round of the video source. Is possible.

Further, similarly to the first embodiment, the present invention can be similarly implemented with a field structure.

(Embodiment 6) FIG. 9 shows an embodiment of the multi-channel image display method.

The upper part 1) of FIG. 9 shows the secondary images 1, 2, 3, 4
The following shows the procedure for displaying on a display in four divided areas. In FIG. 3, for a video source to be displayed, an intra-coded secondary image is input to an inter-frame correlation image decoder 36, decoded, and stored in a frame memory 38. Thereafter, the inter-frame correlation image decoder 36 decodes the secondary image encoded by the forward prediction from the decoded frame and the encoded difference information as needed, and stores the decoded image in the frame memory 38.

The inter-frame correlation image decoder 36 changes the reading order based on the memory address given to the frame memory 38, thereby synthesizing four pixels by a 2 × 2 matrix by an operation reverse to the subsampling at the time of encoding. Generate the decoded SRC1 to SRC4 of the video source. The bit map in which SRC1 to SRC4 are arranged in two rows and two columns is raster-converted and displayed on the display 39.

9 shows the procedure for displaying the secondary images 1 to 16 on the display in 16 divisions. Embodiment 3
Alternatively, according to the procedure of the fourth embodiment, SRC1 to SRC
16 is decoded on the frame memory 38. The bitmaps of SRC1 to SRC16 arranged in 4 rows and 4 columns are raster-converted and displayed on the display 39 while thinning out every other pixel in each of vertical and horizontal directions.

The lower part 3) of FIG. 9 shows, among the secondary images 1 to 16, secondary images of arbitrary nine video sources on the display.
The procedure for split display will be described. The secondary images of the nine video sources are decoded on the frame memory 38 according to the procedure of the third or fourth embodiment. Each secondary image is reduced by 2/3 in each of the vertical and horizontal directions by interpolation such as two-dimensional linear interpolation and stored in the frame memory 38. The bitmap is raster-converted and displayed on a display.

Note that these display processes can be performed regardless of the frame structure and the field structure.

In the first to sixth embodiments described above, the CPU and the DSP (Digital Signal Process) are used.
or) and its programs,
It can be implemented similarly.

[0078]

As described above, according to the present invention, the spatial correlation of an image is converted into the correlation on the time axis, and the one having a strong correlation between the spatial correlation of the image and the time correlation of the image is selected. By performing coding using the selected inter-image correlation, the spatial correlation between adjacent pixels of the original image can be treated as equivalent to the inter-image time correlation, and the stronger one of the spatial correlation and the time correlation is selected. Provided is a multi-channel image encoding apparatus and method which has an excellent effect that a general-purpose encoder / decoder utilizing inter-image correlation can be used while encoding efficiency is increased because encoding is performed. Can be done.

The present invention also provides a method for inputting an image encoded by the above-described multi-channel image encoding apparatus and method, decoding the input image, and decoding the decoded image and the decoded image. By decoding the image from the difference information of the image, the image encoded by the spatial correlation and the time correlation of the image is input as an image encoded by an encoding method equivalent to the time correlation. An excellent general-purpose decoder that decodes the coded image can decode the coded image even with respect to the spatial correlation, and can decode an image with high coding efficiency at low cost. An object of the present invention is to provide a multi-channel image decoding display device and method having an effect.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing one embodiment of an encoding method according to the present invention.

FIG. 2 is an explanatory diagram showing one embodiment of a decoding method according to the present invention.

FIG. 3 is a block diagram of a multi-channel image encoding / decoding display device according to one embodiment.

FIG. 4 is a pixel reference relation diagram of an inter-frame correlation encoding method using a frame structure according to an embodiment;

FIG. 5 is a diagram illustrating a pixel reference relationship in an inter-frame correlation encoding method using a field structure according to an embodiment;

FIG. 6 is an explanatory diagram of an encoding method according to an embodiment.

FIG. 7 is an explanatory diagram of a decoding method according to one embodiment.

FIG. 8 is an explanatory diagram of a variable frame rate of a video source according to one embodiment.

FIG. 9 is an explanatory diagram of a multi-channel screen display method according to one embodiment.

FIG. 10 is a block diagram illustrating an example of a conventional encoding device.

FIG. 11 is an explanatory diagram of pixel selection in a conventional encoding method.

[Explanation of symbols]

 Reference Signs List 30 multiplexer 31 frame synchronizer 32 sub-sampling / reordering unit 33 frame memory 34 inter-frame correlation encoder 35 transmission path or image storage 36 inter-frame correlation decoder 37 inverse sub-sampling / reordering unit 38 frame memory 39 display

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) BC27 BD02 BD03

Claims (22)

[Claims] A conversion unit for converting a spatial correlation of an image into a correlation on a time axis; a selecting unit for selecting a strong correlation between the spatial correlation of the image and the time correlation of the image; Encoding means for performing encoding based on the obtained inter-image correlation. 2. The multi-channel image encoding apparatus according to claim 1, wherein said image has a frame structure or a field structure. 3. The secondary image conversion means for converting a digital image having a frame structure into four secondary images which are sub-sampled every other pixel in both the vertical and horizontal directions; 1st frame 2
A second image showing a next image and an image at the next time of the first frame;
Secondary image extracting means for extracting two second frame secondary images from a frame, wherein the selecting means includes a frame correlation between the first frame secondary images and the first frame secondary image. 2. The multi-channel image encoding apparatus according to claim 1, wherein an image having a strong correlation is selected from inter-frame correlations between the first image and a second image of the second frame. 3. 4. The secondary image conversion means for converting a digital image having a field structure into four secondary images which are sub-sampled every other pixel in both the vertical and horizontal directions; And a secondary image extracting means for extracting two second field secondary images from a second field indicating an image at a time subsequent to the first field. Means for field correlation between the first field secondary image and the first field secondary image and the second field secondary image;
2. The multi-channel image encoding apparatus according to claim 1, wherein a strong correlation is selected from among the inter-field correlations between each one of the field secondary images. 5. An input means for inputting an image coded by the multi-channel image coding apparatus according to claim 1, decoding the input image and decoding the input image. Decoding means for decoding an image from difference information between the decoded image and the decoded image. 6. An image from a plurality of video sources is sub-sampled every other pixel in the vertical and horizontal directions, and four images sub-sampled from different video sources are arranged in a vertical and horizontal square.
A multi-channel image coding apparatus comprising: a secondary image forming unit that forms a next image; and an encoding unit that performs inter-image correlation coding of the secondary image. 7. The multi-channel image encoding apparatus according to claim 6, wherein said image has a frame structure or a field structure. 8. An input means for inputting an image encoded by the multi-channel image encoding device according to claim 6 or 7, decoding the input image, and decoding the decoded image and the decoded image. Decoding means for decoding an image from the difference information with respect to the obtained image. 9. An allocating unit for sub-sampling a plurality of video sources and setting an allocated number of images per unit time for each video source, an encoding unit for encoding the image, and allocating within the unit time. A rate setting unit for setting a transfer rate for each video source according to the number of images obtained. 10. A decoding means for decoding a secondary image whose number of pixels is 1/4 of the original image, which is encoded by sub-sampling every other pixel in the vertical and horizontal directions, and a method for decoding the decoded secondary image in the vertical and horizontal directions. A multi-channel image decoding display device, comprising: display means for arranging in a square and displaying the image in four as one screen. 11. Interpolating means for each of the decoded secondary images, where n is an integer, and the number of pixels is 2 / n each in the vertical and horizontal directions of the secondary image by a two-dimensional interpolation process; , The images after the interpolation are arranged in a vertical and horizontal square.
11. The multi-channel image decoding display device according to claim 10, wherein the screen is divided into n * n displays. 12. A conversion step of converting a spatial correlation of an image into a correlation of a time axis; a selecting step of selecting a strong correlation among the spatial correlation of the image and the time correlation of the image; A coding step of performing coding based on the obtained inter-image correlation. 13. The method according to claim 12, wherein the image has a frame structure or a field structure. 14. The secondary image converting step of converting a digital image having a frame structure into four secondary images sub-sampled every other pixel in both the vertical and horizontal directions, 1st frame 2
A second image showing a next image and an image at the next time of the first frame;
A secondary image extracting step of extracting two second frame secondary images from a frame, wherein the selecting step includes a frame correlation between the first frame secondary image and the first frame secondary image. 13. The multi-channel image encoding method according to claim 12, wherein a strong correlation is selected from among inter-frame correlations between each one of the second frame and the second frame secondary image. 15. The secondary image conversion step of converting a digital image having a field structure into four secondary images that are subsampled every other pixel both vertically and horizontally, and A secondary image extracting step of extracting two first-field secondary images and two second-field secondary images from a second field indicating an image at a time subsequent to the first field. The step of determining the strongest correlation between the field correlation between the first field secondary image and the inter-field correlation between each one of the first field secondary image and the second field secondary image. 13. The multi-channel image encoding method according to claim 12, wherein the method is selected. 16. An input step of inputting an image encoded by the multi-channel image encoding method according to claim 12, decoding the input image, and decoding the input image. A decoding step of decoding an image from difference information between the decoded image and the decoded image. 17. A secondary image forming step of sub-sampling the images of a plurality of video sources at every other pixel in the vertical and horizontal directions, and arranging four images sub-sampled from different video sources in a vertical and horizontal square to form a secondary image. An encoding step of performing inter-image correlation encoding of the secondary image. 18. The method according to claim 17, wherein the image has a frame structure or a field structure. 19. An inputting step of inputting an image encoded by the multi-channel image encoding method according to claim 17 or 18, decoding the input image, and decoding the decoded image and the decoded image. A decoding step of decoding the image from the difference information with respect to the obtained image. 20. Sub-sampling a plurality of video sources, setting an allocation number of images per unit time for each video source, an encoding step of encoding the image, and allocating within the unit time. A rate setting step of setting a transfer rate for each video source according to the number of images obtained. 21. A decoding step of decoding a secondary image whose number of pixels is 1/4 of the original image, which is encoded by sub-sampling every other pixel in the vertical and horizontal directions, and a step of decoding the decoded secondary image in the vertical and horizontal directions. A display step of arranging the images in a square and displaying them as four screens as one screen. 22. An interpolation step in which each of the decoded secondary images is set such that n is an integer and the number of pixels is 2 / n each in the vertical and horizontal directions of the secondary image by a two-dimensional interpolation process; Are arranged in a vertical and horizontal square, and n × n
22. The multi-channel image decoding and displaying method according to claim 21, further comprising a display step of performing split display.