JPH09182068A - Image transmission method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the image transmission efficiency by dividing an original image so as to have these divided images similar to each other, transmitting the divided images after encoding them and giving interpolation to the wrong group via the corresponding part of another similar divided image if an error is detected in a received image. SOLUTION: An image conversion part 10 rearranges an original image to be inputted into plural images of high correlation on every pixel line. Then an encoding part 2 compresses and encodes the converted image data by an H. 261 encoding system or an MPEG1 system and builds the encoded image data into a transmission packet in every encoding unit GOB(group of block) to sends them to a transmission line 4 with addition of an error detection code. When an error is detected at the receiving side via an error detection part 12, an error interpolation part 13 performs the interpolation of the error by copying a normally received corresponding part from a divided image other than that having a wrong part. Then an image inverse conversion part 11 reconfigurates the divided images and outputs them. Thus a transmission error is easily interpolated with high precision and the accuracy of the reconfigurated images can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image transmission method for compressing and encoding image information for transmission and decompressing the transmitted information, and more particularly to efficiently and erroneously transmitting image information erroneous or missing on a transmission path. The present invention relates to an image transmission method capable of high-definition interpolation.

[0002]

2. Description of the Related Art An image transmitting apparatus for realizing a conventional image transmitting method will be described with reference to FIG. FIG. 17 is a configuration block diagram of a conventional image transmission device. As shown in FIG. 17, a conventional image transmission apparatus includes an image input unit 1 for inputting image data, an image encoding unit 2 for compressing and encoding the input image data as an information source, and an information source compression unit, as shown in FIG. And a transmitter 3 for performing error detection coding or error correction coding on the coded data and incorporating the data into a transmission frame and transmitting the transmission frame to a transmission line 4. The reception side receives the transmission frame from the transmission line 4. A receiving unit 5 for performing error detection decoding or error correction decoding, an image decoding unit 6 for decoding received data by information source decompression, and an image output unit 7 for outputting decoded image data. ing.

As the information source compression encoding method in the image encoding unit 2 of the conventional image transmission apparatus, a basic unit (MC
U: Minimun Code Unit: JPEG (Joint Photographic Experts Group) for encoding with 16 pixels x 16 pixels)
ITU that performs encoding in a GOB (Group Of Block) unit that is configured by a method or a plurality (specifically, 33) of MCUs
-T (International Telecommunication Union-Telecom
munication Standardization Sector, International Telecommunication Union-Telecommunication Standardization Sector) 261 system or MPEG1 (Moving Picture Experts Group1) that performs encoding in slice units composed of an arbitrary number of MCUs with MCU width
Methods are known.

Next, an error correction method in the conventional image transmission method will be described. As a countermeasure against an error in the conventional image transmission method, a first error correction method in which an error detection code is added and transmitted in the transmission unit 3 and retransmitted when an error is detected in the reception unit 5, and in the transmission unit 3 A second step in which an error correction code is added and transmitted, and the receiving section 5 performs error correction
There is an error correction method.

[0005]

However, in the conventional image transmission method, when the first error correction method is used, the transmission efficiency is poor due to the retransmission, the delay until the image display occurs, and the error rate is particularly high. There is a problem that images cannot be displayed on the transmission path forever and stable reproduced images cannot be displayed.

In the conventional image transmission method, the second method is used.
Error correction method, it is possible to correct the error when the error on the transmission line is minor, but it becomes impossible when the error is serious, and it is adjusted according to the error characteristic of the transmission line. There is a problem that the efficiency becomes poor unless the error correction code is used.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an image transmission method capable of easily and highly accurately interpolating an error in a transmission line and improving data transmission efficiency. .

[0008]

According to a first aspect of the present invention for solving the above-mentioned problems of the conventional example, in an image transmission method, a pixel in an original image is divided into a plurality of images so as to be similar images. Image conversion is performed, and the image-converted image is information source coded by a block of a specific coding unit,
The information source coded image is subjected to error detection coding in a group unit having a size in which a plurality of blocks are collected, and the image is transmitted to a transmission line, and the image received from the transmission line is subjected to error detection decoding in the group unit, When an error is detected by the error detection decoding, the group including the error portion is replaced with alternative data to perform information source decoding, and after the information source decoding, correspondence of other divided images that resemble the group including the error portion. It is characterized in that the image is inversely transformed by interpolating from the part, and the error in the transmission path can be easily and highly accurately interpolated, and the image transmission can be made efficient.

According to a second aspect of the invention for solving the problems of the conventional example, in the image transmitting method according to the first aspect, the block of a specific coding unit is a macroblock of 16 pixels × 16 pixels. There is ITU-T H.264 as an information source coding method. The feature is that the H.261 system is used, and the error in the transmission path can be simply and highly accurately interpolated, and the image transmission can be made efficient.

According to a third aspect of the present invention for solving the problems of the conventional example, in the image transmitting method according to the first aspect, the block of a specific coding unit is a macroblock of 16 pixels × 16 pixels. The information source coding method is characterized by using the MPEG1 method, which makes it possible to easily and highly accurately interpolate an error in the transmission path and to improve image transmission efficiency.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the claimed invention will be described with reference to the drawings. The image transmission method according to the present invention performs image conversion to create a converted image composed of divided images obtained by dividing an original image into a plurality of pixel lines in the vertical direction or the horizontal direction. The information source compression encoding is performed by the H.261 system or the MPEG1 system, the error detection code is added to the information source compression encoded data, and the data is transmitted. If an error is detected on the receiving side, a divided image in which an error portion exists Interpolated by copying the corresponding part that was normally received from the divided images other than
The divided image is reconstructed, the image is efficiently transmitted, and with respect to an error, a high-definition image can be reproduced by simple interpolation.

First, the first image transmission method of the present invention will be described. The feature of the first image transmission method is that the H.264 / AVC method is used as the information source coding method. The point is that the H.261 method is used. The configuration of an image transmission apparatus (first image transmission apparatus) that realizes the first image transmission method of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing the configuration of a first image transmission device according to the present invention. It should be noted that parts having the same configurations as those in FIG.

As shown in FIG. 1, the first image transmitting apparatus of the present invention includes an image input section 1, an image encoding section 2, and a transmitting section 3 on the side of the transmitting apparatus, which is the same as the conventional one. And a receiving unit 5 and an image decoding unit 6 on the receiving device side.
And the image output unit 7, and the transmitting device and the receiving device are connected via the transmission line 4. Further, as a characteristic part of the present invention, in the transmitting device, the image input unit 1 and the image encoding unit are provided. 2 is provided with an image conversion unit 10, and in the reception device, the error detection unit 1 is provided between the reception unit 5 and the image decoding unit 6.
2 is provided, and an error interpolation unit 13 and an image inverse conversion unit 11 are provided between the image decoding unit 6 and the image output unit 7.

Next, each part of the first image transmission device of the present invention will be specifically described. The image input unit 1 inputs an image signal and outputs digital image data on a screen-by-screen basis.
For analog signals, NTSC (National Televisi
on System Committee) Composite signal, Y / C signal,
PAL (Phase Alternation by Line) signal, SE-CA
These are M (Sequential a Memoire Color Television System) signals and analog RGB signals, and in the case of digital signals, there are digital RGB signals and digital YCrCb signals.

Therefore, when the input image signal is an analog signal, the image input unit 1 must have an A / D converter function for converting the analog image signal into a digital RGB signal or a digital YCrCb signal. . In the case of a general-purpose video signal such as an NTSC composite signal, which is an interlaced (interlaced scan) signal, a rearrangement function of rearranging the input signals to create image data for one screen is also necessary.

In other words, the image input section 1 inputs an image signal, converts it into a digital signal by the function of an A / D converter if it is an analog signal, and rearranges it if it is an interlaced signal to obtain a digital image for one screen. It is designed to output data.

The image conversion unit 10 performs image conversion in which an input image for one screen (original image) is divided into a plurality of pixel lines in the vertical direction or the horizontal direction and rearranged. As will be described later, H.264. In the H.261 system information source coding, since the unit of the information source coding is GOB, vertical division is preferably up to 6 divisions so that one GOB does not include a plurality of divided images. , 2 is suitable for horizontal division.

The image conversion method will be described with reference to the specific examples shown in FIGS. FIG. 2 is an explanatory diagram showing an example of vertical 2-division image conversion in the image transmission method of the present invention, and FIG. 3 is an explanatory diagram showing an example of vertical 4-division image conversion in the image transmission method of the present invention. It is a figure.

As shown in FIG. 2 (a), when the vertical line number of the input original image is 1, 2, ... In the conversion unit 10, a set of only odd lines {1,3, ... L-1}
(Odd line image) and set of only even lines {2,4, ...
By dividing and rearranging into L} (even line image), the original image is converted into an image (two-divided image) divided into two highly correlated images as shown in FIG. 2B, for example. Will be done.

It should be noted that since only the operation of dividing the image in the vertical direction into two parts described here is the reverse operation of the rearrangement of the interlaced signals, the rearrangement of the interlaced signals and the image conversion in the image input section 1 are performed. By omitting both, a two-divided image can be obtained directly from the input image signal.

When the original image is divided into a plurality of pieces in the vertical direction for image conversion, the image is divided by the remainder when the line number in the vertical direction of the original image is divided by the number of divisions. For example, when the original image having the total number of lines L is divided into four, the line numbers of the divided images are {1,5,9, ... L-3} (divided image P1),
{2,6,10 ... L-2} (divided image P2), {3,7,11 ... L-1}
(Divided image P3), {4, 8, 12, ... L} (divided image P4), and the line number of each divided image can be represented by an arithmetic sequence with a difference of 4. As a result, as shown in FIG.
The original image P is divided into four highly correlated images and converted into an image (converted image) composed of the divided images P1, P2, P3, P4.

Next, the image conversion processing in the image conversion unit 10 of the present invention will be described with reference to FIG. FIG. 4 is a flowchart showing the flow of the image conversion processing of the present invention. In FIG. 4, the number of lines in the vertical direction of the original image is L,
The number of divisions is n, and the processing when dividing the original image P into divided images P1, P2, ..., Pn is shown. In the image conversion processing of the present invention, the digital image data of the original image P is input line by line from the image input unit 1 (100), and the remainder i when the line number of each line is divided by the number of divisions n is calculated (102). ), The image data is sequentially stored in the divided image Pi corresponding to the remainder i (104) for all the lines of the original image P.

The image coding unit 2 performs the source coding of the image data of the converted image output from the image conversion unit 10 and outputs it to the transmission unit 3 in coding units. In the first image transmission apparatus, As an information source encoding method, H.264 of ITU-T is used. 2
61 system is used.

H. In the H.261 method, information source coded data (referred to simply as coded data) is considered in a hierarchical structure, and one screen image is CIF (Common Intermediat) as shown in FIG.
e Format: 12 G in case of common intermediate format)
It is divided into units called OB, and each GOB represents a position.
Identify by serial number. Although not shown in the figure, QC
In the case of IF (Quater CIF: 1/4 common intermediate format), it is divided into three GOBs. FIG. It is explanatory drawing which shows the hierarchical structure of the image data in the H.261 system. Then, one GOB has 33 macroblocks (M
B: MacroBlock), and one MB includes luminance information and color difference information of four blocks (one block is 8 × 8 pixels).

Then, H. In the source coding of H.261,
DCT (Discrete Cosine Transform) in block units
Transform and quantize, perform motion-compensated inter-frame prediction in MB units, perform variable-length coding, and include GOB headers that include GOB serial numbers and quantization characteristics so that information source coding can be synchronized in GOB units. It is designed to be added. In addition, H. The H.261 system is described in detail in "Latest MPEG Textbook" edited by Multimedia Communication Research Group, published by ASCII Corporation, p69-p88.

The transmitting unit 3 incorporates the GOB-unit encoded data output from the image encoding unit 2 into a transmission packet (simply referred to as a packet), adds an error detection code, and modulates it according to the transmission line 4. It is then sent out. Here, a specific example of how to incorporate encoded data into a packet will be described with reference to FIG. FIG. 6 shows the first embodiment of the present invention.
FIG. 3 is an explanatory diagram showing a packet format in the image transmission device of FIG.

As shown in FIG. 6A, the packet format in the first image transmission apparatus of the present invention is a header based on a transmission procedure and a fixed length H.264 format. 261 data,
It is composed of an error detection code. And H. 261 data is a method of incorporating coded data of one or more fixed number of GOBs into one packet as an example 1, and for example, as shown in FIG. 6B, n GOs are included in a fixed length packet.
When B is incorporated, n sets of GOB header + data are incorporated, and the redundant portion is filled with binary 1 or 0. Since the GOB header includes the GOB serial number, the position of each GOB can be uniquely determined by the serial number.

On the other hand, H.264 As an example 2 of the H.261 data, in order to remove the redundant part of the example 1 and perform effective transmission, as shown in FIG. 6C, GO included in one packet is used.
The number of H.B. The last GOB including multiple GOB headers + data in the 261 data part
Data may span two packets. However, the receiving side is designed to decrypt only when all the divided GOB data can be received normally.

The receiving section 5 receives the data from the transmission path 4, demodulates it, and outputs it to the error detecting section 12. The error detection unit 12 performs error detection on the demodulated data from the reception unit 5. If no error is detected, the encoded data is output to the image decoding unit 6, and if an error is detected, the packet is The serial number of the GOB (error GOB) included in the transmission frame in which an error is detected is obtained from the serial numbers of the GOBs that are discarded and are normally received before and after the packet, and the serial number is used as the error GOB position information. And output the alternative GOB encoded data to the image decoding unit 6. Here, the alternative GOB coded data is, for example, GOB-unit coded data obtained when the black-color image is source-coded, and is stored in advance in the error detection unit 12.

The image decoding unit 6 outputs the normally received GOB encoded data output from the error detection unit 12 or the substitute G
OB coded data is converted to H.264. The information source is decoded by the H.261 system and the image data is output to the error interpolation unit 13.

The error interpolation unit 13 stores the error GOB position information output from the error detection unit 12, and the image decoding unit 6
The error G for the image data for one screen output from
The pixel value (image data) is interpolated for all the pixels included in the OB. Here, a specific interpolation method will be described with reference to FIGS. 7, 8 and 9. FIG. 7 is an explanatory diagram showing the correlation of images, FIG. 8 is an explanatory diagram showing a concrete example of interpolation in the first image transmission apparatus of the present invention, and FIG. 9 is the first example of the present invention. It is a flowchart figure which shows the flow of the interpolation process in the error interpolation part 13 of an image transmission apparatus.

It is generally known as a characteristic of an image that, as shown in FIG. 7, the correlation between pixels is high in four adjacent pixels in the upper, lower, left, and right adjacent to an arbitrary one pixel, or in the neighboring eight adjacent pixels. Has been. Therefore, in the first image transmission device of the present invention, since the image conversion unit 10 performs image conversion for dividing the original image in the vertical direction or the horizontal direction as described above, the adjacent divided images have high correlation. For example, as shown in FIG. 8, when the error GOB exists on the odd line image side of the two-divided image, the error GOB is detected on the even line image.
Interpolation is performed by copying the pixel value of the pixel located at the same position as each pixel in the error GOB part.

In the interpolation process for one error GOB in the error interpolation unit 13, as shown in FIG. 9, the horizontal position and the vertical position of the error portion are obtained from the error GOB position information (200), and the adjacent position is obtained. This is a process (202) of copying an image from a corresponding position of a divided image to an error portion.
This interpolation process is performed for all error GOBs detected in the screen.

The image inverse transforming unit 11 applies the image transforming unit 1 to the image in which the error GOB portion is interpolated by the error interpolating unit 13.
The image reverse conversion is performed to restore the divided image by the reverse operation of the image conversion performed at 0. The specific processing operation of the image inverse conversion is the same as the image conversion processing described in FIG. 4, and when the processing of FIG. 4 is performed using the interpolated image output from the error interpolation unit 13 as an input image, the image inverse conversion is performed. The image that has been returned to the original state is output.

The image output unit 7 converts the reproduced image according to the output medium and outputs the image signal. The image output unit 7 rearranges the image signal into an interlaced signal or converts the image signal into an analog signal and outputs the analog signal. It has become.

Next, the operation of the first image transmission apparatus of the present invention will be described with reference to FIG. FIG. 10 is an explanatory diagram showing the operation of the first image transmission device of the present invention. In the first image transmission apparatus of the present invention, the input image signal is converted into a non-interlaced digital image by the image input unit 1, the image conversion unit 10 performs the image conversion, and the image encoding unit 2 performs the H.264 conversion. Source coding is performed on a GOB basis using the H.261 system, one or a plurality of GOBs is incorporated in the transmitting unit 3, a packet to which an error detection code is added is created, and the transmission line 4
Sent to

Then, the packet received by the receiving unit 5 and subjected to error detection by the error detecting unit 12 and received normally is the encoded data which is output to the image decoding unit 6 in units of GOB and is transmitted by the H.264 standard. The information source is decoded by the H.261 method. On the other hand, transmission line 4
If an error occurs in the packet m, the error is detected by the error detection unit 12, the data of GOBm incorporated in the packet m is discarded, and the data of the substitute GOB is output to the image decoding unit 6. Source decrypted.
At this time, the error detection unit 12 outputs the serial number of the GOB in which the error has occurred to the error interpolation unit 13 as error GOB position information.

When the image decoding of the information source for one screen in the image decoding unit 6 is completed, the error interpolating unit 13 interpolates the substitute GOB part from the corresponding part of the other divided images based on the error GOB position information. Then, the image reverse conversion unit 11 restores the original image conversion, and the image output unit 7 rearranges the image into an interlaced state or converts it into an analog signal and outputs the image signal.

Next, the second image transmission method of the present invention will be described. The characteristic feature of the second image transmission method is that the MPEG1 system is used as the information source coding method. The basic configuration of an image transmitting apparatus (second image transmitting apparatus) for realizing the second image transmitting method of the present invention is the first configuration shown in FIG.
Is similar to the image transmission device of FIG. 2, but the method of information source coding in the image coding unit 2 is different, and accordingly, the image conversion unit 10, the transmission unit 3, the error detection unit 12, and the image decoding unit 6 are The contents of the error interpolation unit 13 are different.

Each part of the second image transmission device will be described. The image input part 1, the receiving part 5, and the image inverse conversion part 11 are described.
Since the image output unit 7 is exactly the same as that of the first image transmission device, description thereof will be omitted here.

The image conversion unit 10 is, like the first image transmission apparatus, for performing image conversion in which an input image for one screen (original image) is divided into a plurality of pixel line units and rearranged. However, as will be described later, in the information source coding of the MPEG1 system, since the unit of the information source coding is a slice, the dividing direction is limited to the vertical direction, and one slice includes a plurality of divided images. Therefore, up to 15 divisions are suitable for vertical division. The specific image conversion method is performed by the image conversion unit 1 of the first image transmission device.
Since it is exactly the same as 0, the description is omitted here.

The image encoding unit 2 source-codes the image data of the converted image output from the image converting unit 10 and outputs it to the transmitting unit 3 in units of encoding, as in the first image transmitting apparatus. However, the second image transmission apparatus uses the MPEG1 method as the information source coding method.

In the MPEG1 system, the information source coded data (referred to simply as coded data) is considered in a hierarchical structure, and is shown in FIG.
As shown in, the image of one screen is divided into units called slices of arbitrary length. FIG. 11 is an explanatory diagram showing a hierarchical structure of image data in the MPEG1 system. And 1
One slice consists of one or more macroblocks (MB: Ma
croBlock) are arranged in a row in the horizontal direction, and one MB has luminance information and color difference information of four blocks (one block is 8 × 8 pixels).

In MPEG1 information source coding,
DCT (Discrete Cosine Transform) in block units
Transform and quantization are performed, motion compensation inter-frame prediction is performed in MB units to perform variable length coding, and a slice header is added so that information source coding can be synchronized in slice units.

Here, the slice header of MPEG1 includes a slice start code including information on the vertical position of the slice and a quantization scale value which is a quantization characteristic. Specifically, the slice start code is As shown in FIG. 12, it is composed of fixed information of 24 bits and vertical position information of 8 bits. FIG.
It is explanatory drawing which shows the example of a format of the slice start code of MPEG1. Regarding the MPEG1 system,
"Latest MPEG Textbook", Multimedia Communication Study Group
Published by ASCII Corporation, p89 to p124.

The transmitting unit 3 incorporates the encoded data in units of slices output from the image encoding unit 2 into a packet, adds an error detection code, modulates it according to the transmission path 4, and transmits it. . Here, a specific example of how to incorporate encoded data into a packet will be described with reference to FIG. FIG. 13 is an explanatory diagram showing a packet format in the second image transmission device of the present invention.

As shown in FIG. 13A, the packet format in the second image transmission apparatus of the present invention is composed of a header based on the transmission procedure, fixed length MPEG1 data, and an error detection code. As MPEG1 data, as an example 1, as shown in FIG. 13B, a method of incorporating coded data of one or a plurality of fixed number of slices into one packet is used. When incorporating slices, n sets of slice header + data are incorporated, and the redundant part includes binary 1 or 0.
Will be filled with. Since the slice header includes vertical position information of the slices, for example, if each slice is one slice in the horizontal direction as shown in FIG. 11, the position of the slice in the image of one screen is unique. You can decide.

On the other hand, as Example 2 of MPEG1 data, in order to remove the redundant part of Example 1 and perform effective transmission, as shown in FIG. 13C, the number of slices included in one packet is variable. And the last slice data is 2
It may be extended over one packet. And
The serial number of the first slice and the serial number of the last slice in the packet are added to the beginning of the packet. The slice length and serial number must be the same on the transmitting side and the receiving side. Further, the receiving side is designed to decode only when all the data of the divided slices can be normally received.

The error detecting section 12 detects an error in the demodulated data from the receiving section 5, outputs the coded data to the image decoding section 6 when no error is detected, and when the error is detected, The packet is discarded, the serial number of the slice (error slice) included in the transmission frame in which an error is detected is obtained from the vertical position of the slice or the serial number included in the packet that was normally received before and after that packet, and the serial number is the error slice. The position information is output to the error interpolation unit 13 and the alternative slice encoded data is output to the image decoding unit 6. Here, the alternative slice coded data is, for example, coded data in slice units, which is obtained when source black-color images are subjected to information source coding, and is stored in the error detection unit 12 in advance.

The image decoding unit 6 source-decodes the encoded data of the normally received slice or the alternative slice encoded data output from the error detection unit 12 by the MPEG1 method and outputs the image data to the error interpolation unit 13. To do.

The error interpolation unit 13 stores the error slice position information output from the error detection unit 12, and with respect to the image data for one screen output from the image decoding unit 6, for all pixels included in the error slice. The pixel value (image data) is interpolated. Here, a specific interpolation method will be described with reference to FIGS. 14 and 15. FIG.
FIG. 15 is an explanatory diagram showing a specific example of interpolation in the second image transmission device of the present invention, and FIG. 15 is a flowchart diagram showing a flow of interpolation processing in the error interpolation unit 13 of the second image transmission device.

For example, as shown in FIG. 14, when an error slice exists on the odd line image side of the two-divided image, the pixel value of the pixel at the same position as each pixel of the error slice in the even line image is used as the error slice portion. Interpolation is performed by copying to.

Therefore, the interpolation processing for one error slice in the error interpolation unit 13 is performed as shown in FIG.
This is a process of obtaining the horizontal position and the vertical position of the error part from the error slice position information (300) and copying the image from the corresponding position of the adjacent divided image to the error part (302), which is detected in one screen. This interpolation process is performed for all error slices.

Next, the operation of the second image transmission device of the present invention will be described with reference to FIG. FIG. 16 is an explanatory diagram showing the operation of the second image transmission device of the present invention. In the second image transmission apparatus of the present invention, the input image signal is converted into a non-interlaced digital image by the image input unit 1, the image conversion unit 10 performs the image conversion, and the image encoding unit 2 uses the MPEG1 system. Source-coded on a slice-by-slice basis, the transmitter 3 creates one or a plurality of slices, creates a packet to which an error detection code is added, and creates a packet.
Sent to

Then, the packet received by the receiving unit 5 and subjected to error detection by the error detecting unit 12 and normally received is output to the image decoding unit 6 in slice units and information source decoding is performed by the MPEG1 system. . On the other hand, if an error occurs in the packet m on the transmission path 4, the error detection unit 12 detects the error, the slice m incorporated in the packet m is discarded, and the alternative slice is output to the image decoding unit 6. And the information source is decrypted. At this time, the error detector 12 outputs the vertical position or serial number of the slice in which the error has occurred to the error interpolator 13 as error slice position information.

When the source decoding for one screen in the image decoding unit 6 is completed, the error interpolation unit 13 interpolates an alternative slice portion from a corresponding portion of another divided image based on the error slice position information. Then, the image reverse conversion unit 11 restores the original image conversion, and the image output unit 7 rearranges the image into an interlaced state or converts it into an analog signal and outputs the image signal.

According to the image transmission method of the present invention, the H.264 standard is used. 26
If the information source compression encoding is performed in each encoding unit using the 1 system or the MPEG1 system and the error detection code is added to the information source compression encoded data for transmission, if an error is detected on the receiving side. Since the interpolation is performed from the normally received portion, there is an effect that the deterioration of the transmission efficiency due to retransmission or the like can be prevented, and stable image transmission and reproduced image display can be always performed.

According to the image transmission method of the present invention, the original image is divided into a plurality of divided images and rearranged, and image conversion is performed.
Regarding the converted image, H.264. 261 system or MPEG1
Information source compression encoding is performed in each encoding unit using the method, and error detection code is added to the information source compression encoded data for transmission. If an error is detected on the receiving side, the encoding unit After the information source decoding is performed with the alternative data and the one-screen information source decoding is completed, interpolation is performed by copying the normally received corresponding portion of the other divided image to the error portion, and then dividing the divided image again. Since it is configured, since a normally received image having a high correlation is interpolated by a method of simply copying it, there is an effect that a transmission error can be easily and highly accurately interpolated to improve the accuracy of a reproduced image.

[0059]

According to the present invention, the original image is divided so that the images are similar to each other, and the divided image is divided into blocks of a specific coding unit, for example, ITU-T H.264.
Source coding using the H.261 system or MPEG1 system, and further, error detection coding is performed on a group in which a plurality of blocks are collected, image transmission is performed to a transmission line, and an image received from the transmission line is error detection decoded in group units, If there is an error, the group containing the error is replaced with alternative data, the information source is decoded, and then the group containing the error is interpolated from the corresponding parts of other similar divided images. On the other hand, there is an effect that interpolation can be performed easily and in high definition, and image transmission can be made efficient.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of a first image transmission device according to the present invention.

FIG. 2 is an explanatory diagram showing an example of vertically divided image conversion in the image transmission method of the present invention.

FIG. 3 is an explanatory diagram showing an example of vertical 4-division image conversion in the image transmission method of the present invention.

FIG. 4 is a flowchart showing a flow of image conversion processing of the present invention.

FIG. It is explanatory drawing which shows the hierarchical structure of the image data in the H.261 system.

FIG. 6 is an explanatory diagram showing a packet format in the first image transmission device of the present invention.

FIG. 7 is an explanatory diagram showing the correlation of images.

FIG. 8 is an explanatory diagram showing a specific example of interpolation in the first image transmission device of the present invention.

FIG. 9 is a flowchart showing a flow of interpolation processing in the error interpolation unit of the first image transmission device of the present invention.

FIG. 10 is an explanatory diagram showing an operation of the first image transmission device of the present invention.

FIG. 11 is an explanatory diagram showing a hierarchical structure of image data in the MPEG1 system.

FIG. 12 is an explanatory diagram showing a format example of a slice start code of MPEG1.

FIG. 13 is an explanatory diagram showing a packet format in the second image transmission device of the present invention.

FIG. 14 is an explanatory diagram showing a specific example of interpolation in the second image transmission device of the present invention.

FIG. 15 is a flowchart showing a flow of interpolation processing in the error interpolation unit 13 of the second image transmission device.

FIG. 16 is an explanatory diagram showing an operation of the second image transmission device of the present invention.

FIG. 17 is a configuration block diagram of a conventional image transmission device.

[Explanation of symbols]

1 ... Image input unit, 2 ... Image encoding unit, 3 ... Transmission unit,
4 ... Transmission path, 5 ... Reception unit, 6 ... Image decoding unit,
7 ... Image output unit, 10 ... Image conversion unit, 11 ... Image inverse conversion unit, 12 ... Error detection unit, 13 ... Error interpolation unit

Claims (3)

[Claims] 1. An image conversion in which pixels in an original image are divided into a plurality of images so as to form similar images, the image-converted image is information-source coded by a block of a specific coding unit, and the information source The coded image is subjected to error detection coding in a group unit having a size in which a plurality of blocks are collected, the image is transmitted to a transmission line, the image received from the transmission line is subjected to error detection decoding in the group unit, and the error detection decoding is performed. When an error is detected in the encoding, the group including the error portion is replaced with alternative data to perform information source decoding, and after the information source decoding, the group including the error portion is interpolated from corresponding portions of other similar divided images. An image transmission method characterized by performing inverse image conversion. 2. A block of a specific coding unit is a macroblock of 16 pixels × 16 pixels, and the information source coding method is ITU-T H.264. The image transmission method according to claim 1, wherein the H.261 system is used. 3. The image transmission according to claim 1, wherein the block of the specific coding unit is a macro block of 16 pixels × 16 pixels, and the MPEG1 method is used as the information source coding method. Method.