JPH10145786A - Image communication method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the retransmission frequency and to shorten the transmission time by restransmitting some of divided images which are highly correlative with each other and transmitting other divided images with high efficiency via the error correction encoding. SOLUTION: An original image is divided into plural images by an image divider 13 at the transmitter side, and one or more divided images are defined as the divided images A with others defined as the divided images B respectively. A communication control part 4a decides whether the divided image encoding data of the output of a Huffman encoder 3 are coincident with the images A or B. An error detection encoder 5 applies the error detection encoding to encoding data on the images A and produces an HDLC frame to transmit it via a modulator 6. An error correction encoder 16 applies the error correction encoding to the encoding data on the images B and produces an HDLC frame with addition of a synchronous header to transmit the frame via the modulator 6. At the receiver side, a communication control part 8a decides whether the data transmitted via a channel are coincident with the data A or B via a demodulator 7 and the synchronous header. Then the original image is composited by an image compositor 14 in a process adverse to the transmitter side, and the reproduced image data are outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image communication method and an image communication apparatus for compressing and transmitting an image, and in particular, to efficiently transmit an image while maintaining a certain degree of accuracy even on a communication path having poor line quality. The present invention relates to an image communication method and an image communication device capable of transmitting.

[0002]

2. Description of the Related Art First, a conventional JPEG (Joint Photogra
The image communication apparatus of the phic Experts Group (ITU-T T.81) method will be described with reference to FIG. FIG. 10 shows a conventional J
FIG. 2 is a configuration block diagram of a PEG image communication device. As shown in FIG. 10, a conventional JPEG-based image communication device has a discrete cosine transformer 1, a quantizer 2,
Communication comprising a Huffman encoder 3, a communication control unit 4 ′ having an error detection encoder 5 therein, and a modulator 6, wherein the receiving side has a demodulator 7 and an error detection decoder 9 therein. It comprises a control unit 8 ', a Huffman decoder 10, an inverse quantizer 11, and an inverse discrete cosine transformer 12, and the transmission side and the reception side are connected via a communication path.

Next, each section of the conventional image communication apparatus will be described. The discrete cosine transformer 1 converts the digitally converted input image data into an encoded block (for example, 8 × 8 pixels or 16 × 16 pixels, hereinafter simply referred to as a block).
Discrete Cosine Transform (DC)
T) Perform transform coding for transforming and outputting DCT coefficients.

The quantizer 2 quantizes the DCT coefficients transformed and coded by the discrete cosine transformer 1, and outputs quantized coefficients obtained by reducing the number of effective coefficients. The Huffman encoder 3 entropy-encodes the quantized coefficients quantized by the quantizer 2 and outputs information source encoded data (encoded data). As an example of entropy encoding, Huffman encoding is performed. It has been known.

The error detection encoder 5 adds an error detection code for detecting a transmission error to the encoded data output from the Huffman encoder 3, and as an example of the error detection code, There is a CRC (Cyclic Redundancy Checks) code which is known to be able to detect both an independent error that occurs independently and a burst error in which the error occurs continuously. In general, a CRC generating polynomial is represented by x in ITU-T. ¹⁶
+ X ¹² + x ⁵ +1 is used. Details regarding CRC are described in "Computer Communication and Network", Kunio Fukunaga, Kyoritsu Shuppan Co., Ltd., pp. 78-82.

The communication control unit 4 ′ incorporates the data to which the error detection code has been added by the error detection encoder 5 into a transmission frame in accordance with a transmission control procedure and outputs the data to the modulator 6. Note that one or more blocks of information source encoded data are incorporated in one transmission frame.

[0007] Here, as an example of the transmission control procedure, there is a synchronous procedure in which variable-length data can be transmitted in bit units and a highly reliable transmission can be performed by making a retransmission request when an error is detected. HDLC (High level Data Link
Control) procedure is common.

As shown in FIG. 11, a transmission frame, which is a transmission unit in the HDLC procedure, includes a flag for detecting the start of a frame, a transmission destination address, and a control for setting a command or response in accordance with the procedure. ,
Variable-length data to be transmitted, that is, image data (information source coded data) and an error correction code (here, C
(RC code) and a flag for detecting the end of the frame. FIG. 11 is an explanatory diagram showing a transmission frame format of the HDLC procedure. HDL
For details on Procedure C, see "Computer Communication and Networking."
It is described in Kunio Fukunaga, Kyoritsu Shuppan Co., Ltd. p113-p130.

In the HDLC procedure, when an error in a frame unit is detected on the receiving side, a retransmission request (retransmission command) is transmitted. Therefore, the communication control unit 4 'responds to the retransmission request from the receiving side. Then, a frame retransmission operation is also performed.

The modulator 6 modulates transmission data into a signal suitable for a communication channel and sends the signal to the communication channel. Demodulator 7
Is for demodulating the transmission data received from the communication path and outputting it to the communication control unit 8 '.

The error detection decoder 9 performs error detection on the demodulated received data. The communication control unit 8 '
Processing is performed according to the communication control procedure. In particular, when an error is detected, a retransmission request (retransmission command) is transmitted according to the HDLC procedure, and exchange is performed until error-free data can be received. . Then, for the data without error, the information source coded data portion is extracted and output to the Huffman decoder 10.

The Huffman decoder 10 includes a communication control unit 8 '
The dequantizer 11 dequantizes the quantized coefficient from the Huffman decoder 10 and outputs a DCT coefficient by entropy decoding the encoded data without error received from the Huffman decoder 10. The inverse discrete cosine transformer 12 performs inverse discrete cosine transform of the DCT coefficient from the inverse quantizer 11 and outputs image data decoded by an information source.

Next, the operation of the conventional image communication apparatus will be described with reference to FIG. In a conventional image communication apparatus, when image data of an image to be transmitted to a transmission side is input, the image data is subjected to discrete cosine transform by a discrete cosine transformer 1, quantized by a quantizer 2, and entropy-coded by a Huffman encoder 3. In the communication control unit 4 ', an error detection code is added by an error detection encoder 5 and incorporated in an HDLC frame, modulated by a modulator 6, and transmitted to a communication path.

On the receiving side, the data received from the communication channel is demodulated by the demodulator 7, the error is detected by the error detection decoder 9 in the communication control unit 8 ′, and the frame in which the error is detected is retransmitted. The request is sent to the transmitting side via the demodulator 7, and the communication control unit 4 ′ receiving the retransmission request via the modulator 6 retransmits the frame for which the retransmission request has been made.

For a frame in which no error is detected by the error detection decoder 9 in the communication control unit 8 ', an information source coded data portion is taken out, entropy decoded by a Huffman decoder 10, and inversely quantized. The inverse discrete cosine transform unit 12 performs inverse discrete cosine transform on the inverse discrete cosine transform, decodes the information source, and outputs image data.

[0016]

However, in the conventional image communication apparatus described above, when transmitting an image over a communication path having a high error rate, such as wireless communication, the frequency of retransmission is high, and the communication time becomes extremely long, resulting in an increase in transmission efficiency. However, there was a problem that it was not practical.

The present invention has been made in view of the above circumstances, and an image communication method and an image communication method capable of efficiently transmitting an image in a short time while maintaining a certain degree of accuracy even on a communication path having a high error rate. It is intended to provide a device.

[0018]

According to a first aspect of the present invention, there is provided an image communication method, comprising the steps of: transmitting an original image data of one frame of an original image on a transmitting side; A plurality of divided images are formed from the original image by performing subsampling in which the pixel number is divided by an integer and divided by a quotient and a quotient to form a plurality of divided images, and a divided image A that is one or more preselected divided images And the divided image B, which is the remaining divided image. The divided image A is subjected to information source encoding and error detection encoding and transmitted, and the divided image B is subjected to information source encoding and error correction. Encoded and transmitted,
On the receiving side, for the divided image A, when an error is detected, retransmission is performed, and when it is received normally, the information source is decoded and reproduced, and for the divided image B, the error is corrected and the information source is decoded. It is characterized in that the reproduced divided image A and the divided image B are reproduced and the original image is reproduced by rearranging the pixels by the reverse method of the sub-sampling, and a part of the divided image having a high degree of correlation with each other. Is reliably transmitted by retransmission, and the remainder is transmitted without retransmission by error correction coding even if there are some errors, so that the frequency of retransmission is reduced even on a communication path with a high error rate, and a certain degree of accuracy is achieved. Images can be transmitted efficiently in a short time while holding them.

According to a second aspect of the present invention, there is provided an image communication apparatus, comprising:
Image dividing means for sub-sampling original image data of a frame to create a plurality of divided images from the original image, encoding means for compressing and encoding image data of the divided image to create encoded data, The images are classified into a divided image A, which is one or a plurality of pre-selected divided images, and a divided image B, which is the remaining divided image.
The encoded data of the divided image B is transmitted after being subjected to error detection encoding, and the encoded data of the divided image B is subjected to error correction encoding and transmitted.
Receiving means for separating the encoded data of the divided image A, retransmitting the data when an error is detected, and performing error correction on the encoded data of the divided image B; Decoding means for decompressing and decoding the encoded data of the divided image A and the encoded data of the error-corrected divided image B, and a method of reversing the sub-sampling from the reproduced divided image A and the divided image B And image synthesizing means for reconstructing the original image by rearranging the pixels in a part of the divided images having a high degree of correlation with each other. However, by transmitting without retransmission by error correction coding, it is possible to reduce the frequency of retransmission even on a communication path with a high error rate and to transmit images efficiently in a short time while maintaining a certain level of accuracy. That.

According to a third aspect of the present invention, there is provided an image communication method comprising the steps of:
A plurality of divided images are formed from the original image by performing sub-sampling in which the original image data of one frame of the original image is grouped and arranged by a quotient and a remainder obtained by dividing a pixel number of a pixel by an integer, and a plurality of divided images are formed in advance. The divided image A is divided into one or a plurality of divided images and the remaining divided image is divided image B, and the divided image A and the divided image B are each subjected to information source coding to perform error detection. Encoded and transmitted, and the receiving side retransmits the divided image A when an error is detected, decodes and reproduces the information source when received normally, and detects the error with the divided image B on the receiving side. In the case of being discarded, the normally received encoded data is decoded by information source and reproduced, and the reproduced divided image A and divided image B are rearranged in the reverse method of the sub-sampling to rearrange the pixels. Split image The original image is reproduced by interpolating the discarded image portion of the original image from surrounding pixels.Some of the divided images with high correlation are reliably transmitted by retransmission, and the rest are discarded error portions. By interpolating the discarded parts from the surroundings after combining the reproduced divided images, the frequency of retransmission can be reduced even on a communication channel with a high error rate, and an image can be efficiently generated in a short time while maintaining a certain degree of accuracy. Can be transmitted.

According to a fourth aspect of the present invention, there is provided an image communication apparatus, comprising:
Image dividing means for sub-sampling original image data of a frame to create a plurality of divided images from the original image, encoding means for compressing and encoding image data of the divided image to create encoded data, The images are classified into a divided image A, which is one or a plurality of pre-selected divided images, and a divided image B, which is the remaining divided image.
The encoded data of the divided image B is transmitted after error detection encoding, and the encoded data of the divided image B is transmitted with the error detection encoding added with position information, and the transmitted data is divided into divided images. A and the divided image B, and when an error is detected in the encoded data of the divided image A, retransmission is performed. For the encoded data of the divided image B,
If an error is detected, it is discarded and output means for outputting error block information indicating an error position in the image; the encoded data of the normally received divided image A and the divided image B;
Decoding means for decompressing and decoding the coded data, and image synthesizing means for rearranging the pixels of the reproduced divided image A and the divided image B in the reverse manner of the sub-sampling. Interpolating a discarded image portion of the divided image B in the divided image data from surrounding image data based on the error block information to reproduce an original image. A part of the high-resolution divided image is reliably transmitted by retransmission, the remaining part is discarded with an erroneous part, and after combining the reproduced divided images, the discarded part is interpolated from the surroundings to form a communication path with a high error rate. However, it is possible to efficiently transmit images in a short time while reducing the retransmission frequency and maintaining a certain degree of accuracy.

According to a fifth aspect of the present invention, there is provided an image communication method comprising the steps of:
A plurality of divided images are formed from the original image by performing sub-sampling in which the original image data of one frame of the original image is grouped and arranged by a quotient and a remainder obtained by dividing a pixel number of a pixel by an integer, and a plurality of divided images are formed in advance. The divided image A, which is one or more divided images, and the divided image B, which is the remaining divided image, are divided into the divided images A, and the divided images A are subjected to information source encoding, error detection encoding, and transmitted. The divided image B is subjected to information source coding and error correction coding and transmitted, and the receiving side discards the divided image A when an error is detected, and decodes and reproduces the information source when received normally. The divided image B is subjected to error correction, information source decoding and reproduction, and the reproduced divided image A and divided image B are rearranged in the reverse method of the sub-sampling to perform pixel rearrangement. Abolition in A The original image is reproduced by interpolating the extracted image part from surrounding pixels.Some of the divided images with high correlation are discarded without retransmitting the erroneous part, and the rest are corrected for some errors. Even if it is included, it is transmitted without retransmission by error correction coding, and by interpolating from the surroundings the part discarded after synthesizing the reproduced divided image, even if it is a communication path with a high error rate, it does not perform retransmission and communication time Can be greatly reduced, and images can be transmitted with a certain degree of accuracy.

According to a sixth aspect of the present invention, there is provided an image communication apparatus, comprising:
Image dividing means for sub-sampling original image data of a frame to create a plurality of divided images from the original image, encoding means for compressing and encoding image data of the divided image to create encoded data, The images are classified into a divided image A, which is one or a plurality of pre-selected divided images, and a divided image B, which is the remaining divided image.
The encoded data of the divided image B is transmitted by performing error detection encoding by adding position information, and the encoded data of the divided image B is transmitted by performing error correction encoding. A and the divided image B, the encoded data of the divided image A is discarded when an error is detected, and error block information indicating an error position in the image is output. Receiving means for performing error correction on the encoded data, decoding means for decompressing and reproducing the encoded data of the normally received divided image A and the encoded data of the error-corrected divided image B, Image synthesizing means for rearranging the pixels of the reproduced divided image A and the divided image B in the reverse method of the sub-sampling, and the divided image A in the rearranged image data
And interpolating means for interpolating the discarded image portion from the surrounding image data based on the error block information to reproduce the original image. Even if there is some error, the remainder is transmitted without retransmission by error correction coding, and the part discarded after combining the reproduced divided images is interpolated from the surroundings, so that it can be used on a communication path with a large error rate. Even if there is no retransmission, the communication time can be greatly reduced and the image can be transmitted with a certain degree of accuracy.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the claimed invention will be described with reference to the drawings. In a first image communication method according to the present invention, a transmitting side divides (sub-samples) an original image into pixels in a vertical direction or a horizontal direction or a vertical and horizontal direction for each pixel, and In addition, a general information source coding is performed, and one or more pre-selected divided images in the divided images are divided into divided images A
Then, the remaining divided images are transmitted as error-correction-coded as the divided image B, and if an error is detected in the transmission data of the divided image A on the receiving side, retransmission is performed. For B, error-correction decoding was performed, and the information-source-decoded information of the normally received divided image A and the error-correction-decoded information of the divided image B were decoded and reproduced. The original image is reproduced by synthesizing the divided images.Parts of the divided images with high correlation are transmitted reliably by retransmission, and the remaining parts are transmitted efficiently even if they contain some errors by error correction coding. By doing so, it is possible to reduce the retransmission frequency and transmit images efficiently in a short time while maintaining a certain degree of accuracy even on a communication path having a high error rate.

First, the configuration of an image communication apparatus for realizing the first image communication method according to the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing the configuration of an image communication apparatus for realizing a first image communication method according to the present invention. Note that FIG.
Portions having the same configuration as those described above will be described with the same reference numerals.

As shown in FIG. 1, an image communication apparatus (first apparatus) for realizing a first image communication method according to the present invention includes a discrete cosine transformer 1 as a part similar to a conventional one.
, A quantizer 2, a Huffman encoder 3, and a modulator 6. Further, as a characteristic part of the present invention, in addition to the image divider 13 and the conventional error detection encoder 5, error correction is performed. A communication control unit 4a having an encoder 16 therein is provided.

The receiving side has a demodulator 7, a Huffman decoder 10, an inverse quantizer 11, and an inverse discrete cosine transformer 12, which have the same configuration as the conventional one. As a characteristic part, the conventional error detection decoder 9
In addition, a communication control unit 8a having an error correction decoder 17 therein and an image synthesizer 14 are provided.

Next, the components of the first device will be described in detail. The discrete cosine transformer 1, the quantizer 2,
Huffman encoder 3, error detection encoder 5, modulator 6, demodulator 7, error detection decoder 9, Huffman decoder 10, inverse quantizer 11, inverse discrete cosine Since the converter 12 is completely the same as the conventional one, the description is omitted here.

The image divider 13 performs sub-sampling for dividing the original image into a plurality of images, creates a plurality of sub-sampled images (divided images), and encodes each divided image with an encoding block (for example, 8 × 8 pixels). The image data is output to the discrete cosine transform unit 1 in units of 16 or 16 × 16 pixels (hereinafter simply referred to as a block).

Here, the subsampling method will be described using three examples. As a first example, when one frame of a still image (original image) is composed of k pixel lines in the vertical direction, the remainder is obtained by dividing the line number of the k pixel lines by an integer n. The image data is divided into n groups, and the pixel data for each line in each group are arranged in ascending order of the quotient of the division result to create n divided images.

As a second example, when the original image is composed of s pixels in the horizontal direction, the group is divided into m groups by the remainder obtained by dividing the pixel number of the s pixels by an integer m. And
Furthermore, m divided images are created by arranging pixel data for each pixel in each group in ascending order of the quotient of the division result.

As a third example, when the original image is composed of s pixels in the horizontal direction and the horizontal pixel line is composed of t pixels in the vertical direction, the pixel number of the s pixels Is divided into m × n groups by the remainder when dividing the pixel number by an integer m and the remainder when dividing the line number of t pixel lines by n, and furthermore, the pixel data of each pixel in each group is divided by The quotients are arranged in ascending order to create m × n divided images.

Here, for simplicity of explanation, an example will be described in which the original image is divided into two in the vertical direction to create a divided image using the first example. That is, assuming that each pixel value is p (x, y) for an original image composed of H pixels in the vertical direction, the method of creating the divided images A and B is as follows. Split image A = a (i, j) = p (i, 2j) Split image B = b (i, j) = p (i, 2j + 1) where 0 ≦ j <H / 2.

Since each divided image is created by sequentially extracting pixel values of rows or columns adjacent to each other, the divided images are similar to each other with a high degree of correlation.

The communication control section 4a controls communication on the transmission side. Specifically, the communication control section 4a receives coded data in block units from the Huffman coder 3, and outputs the divided image A from the block order. And whether the image is a divided image B,
The encoded data of the divided image A is error-detection-encoded by the error-detection encoder 5 to create an HDLC frame in one or an arbitrary number of encoding units, output to the modulator 6, and prepare for retransmission. Remember. Then, when a retransmission command is received from the receiving side, the frame is retransmitted.

The encoded data of the divided image B is error-correction-encoded by the error-correction encoder 16 and one or a plurality of encoding units are put together to form a synchronization header as shown in FIG. Is generated and output to the modulator 6. FIG. 2 is an explanatory diagram showing a transmission frame format of the divided image B subjected to error correction coding in the first image communication device of the present invention.

The error correction encoder 16 performs error correction encoding on the encoded data from the Huffman encoder 3. As an error correction code, BCH (Bose Chaudhuri H
ocquenghem) codes are known, for example BCH (1
When the encoding is performed in (6, 8), 8 bits of error correction code is added to 8 bits of data, and the generator polynomial has a BCH having x ⁸ + x ⁷ + x ⁶ + x ⁴ + x ² + x + 1.
It is obtained by shortening (17, 9) and is widely used.

When receiving the encoded data of the divided image demodulated from the demodulator 7, the communication control unit 8a determines whether the image is the divided image A or the divided image B based on the synchronization header, and The coded data is subjected to error detection decoding by the error detection decoder 9 and the normally received coded data is output to the Huffman decoder 10. If an error is detected, the retransmission command of the retransmission request is demodulated. Is transmitted from the transmitter 7 to the transmitting side.

On the other hand, the coded data of the divided image B is subjected to error correction decoding by the error correction decoder 17 and the coded data is output to the Huffman decoder 10.

The image synthesizer 14 rearranges the image data of the divided image A and the divided image B, which have been subjected to the information source decoding, from the inverse discrete cosine transformer 12 by a method reverse to that of the image divider 13 and based on the array. The up-sampling is performed, the divided images are combined, and the original image is reproduced.

The correspondence between the components of the first embodiment described above and the respective means of the second embodiment is determined by the image divider 13
Corresponds to an image dividing unit, the discrete cosine transformer 1, the quantizer 2, and the Huffman encoder 3 correspond to an encoding unit, the communication control unit 4a and the modulator 6 correspond to a transmitting unit,
The demodulator 7 and the communication control unit 8a correspond to a receiving unit, the Huffman decoder 10, the inverse quantizer 11, and the inverse discrete cosine transformer 12 correspond to a decoding unit, and the image combiner 14 corresponds to an image combining unit. It is equivalent.

Next, the operation of the first image communication apparatus according to the present invention will be described with reference to FIG. First of the present invention
When image data of an image (original image) to be transmitted to the transmission side is input to the image communication device, the image communication device 13 performs subsampling by the image divider 13 to generate a plurality of divided images. And
One or a plurality of pre-selected divided images are referred to as a divided image A, and the remaining divided images are referred to as a divided image B.

Then, the image data is input to the discrete cosine transform unit 1 for each divided image in coding block units, and the discrete cosine transform is performed in the discrete cosine transform unit 1 in the same manner as in the prior art, and the obtained DCT coefficients are quantized. The number of effective coefficients is reduced by the quantizer 2 and further entropy-coded by the Huffman encoder 3 to obtain information source encoded data (hereinafter simply referred to as encoded data) for each encoding unit of the divided image. ) Is output to the communication control unit 4a.

The communication controller 4a determines whether the encoded data of the divided image output from the Huffman encoder 3 is the divided image A or the divided image B according to the order, and determines the code of the divided image A. The encoded data is sent to the error detection encoder 5
, An HDLC frame is created, modulated by the modulator 6 and transmitted.

On the other hand, in the encoded data of the divided image B, one or a plurality of encoded data are put together, error-correction-encoded by the error-correction encoder 16, a synchronization header is added, and an HDLC frame is created. Then, the signal is modulated by the modulator 6 and transmitted.

On the receiving side, the data transmitted through the communication path is demodulated by the demodulator 7 by following the reverse process of the transmitting side, and the divided image A and the divided image B are transmitted from the synchronization header by the communication control unit 8a. Is determined.

When an error is detected by the error detection decoder 9, a retransmission request is transmitted from the demodulator 7 to the transmission side, and the coded data of the divided image A is retransmitted by the communication control unit 4a. If no error is detected by the detection decoder 9, the encoded data is output to the Huffman decoder 10.

On the other hand, the encoded data of the divided image B is subjected to error correction decoding by the error correction decoder 17 and output to the Huffman decoder 10.

Then, the encoded data of the normally received divided image A and the encoded data of the divided image B subjected to error correction decoding are entropy-decoded by the Huffman decoder 10 as in the prior art, Quantizer 11 performs inverse quantization,
Reproduced image data that has been subjected to inverse discrete cosine transform by the inverse discrete cosine transformer 12 and decompressed and decoded is output to the image synthesizer 14.

Then, in the image synthesizer 14, the reproduced image data of the divided images are rearranged to synthesize the original arrangement of the images, and output as the reproduced image data of the original image.

The number of divided images to be divided by the image divider 13 and the number of divided images to be treated as the divided image A in the divided images are set in advance. The number of divisions and the number of divided images A are determined depending on whether or not the communication time is reduced. For example, when the number of divisions is increased and the number of divided images A is decreased, the reproduction accuracy is reduced, but the retransmission frequency is reduced and the communication time can be reduced.

Although the discrete cosine transform is used for transform coding in the present invention, the Karhunen-Loeve transform may be used. In the present invention, Huffman coding is used for entropy coding. Coding may be used. Further, other encoding techniques may be used in combination.

FIG. 3 shows a comparison between the case of transmitting an image using the first image communication method of the present invention and the conventional method in relation to the error rate of the communication path and the communication time. To
In the case of the image communication method of the present invention, when the error rate is small,
The communication time is longer than before by the error correction code compared to the error detection code, but the retransmission frequency is reduced at locations where the error rate is large because the amount of coded data to be retransmitted is smaller than in the conventional method. It can be seen that the communication time is shortened. FIG. 3 is an explanatory diagram illustrating a relationship between an error rate of a communication channel and a communication time.

According to the first image communication method and the first image communication apparatus of the present invention, the original image is divided on the transmitting side, error detection decoding is performed on some of the divided images, and the coded data having an error is Retransmitted, the remaining divided images are error-correction coded and transmitted, and the coded data of the divided image transmitted reliably by retransmission and the code of the divided image transmitted by error correction coding, although containing some errors Since the original image is reproduced by decoding the decoded data and synthesizing the divided images, the transmission efficiency can be improved by reducing the retransmission frequency while maintaining a certain level of accuracy even on a communication path with a high error rate. There is.

Next, an image communication method according to a second embodiment capable of improving transmission efficiency while maintaining a certain degree of accuracy, as in the first image communication method, will be described with reference to the drawings. In a second image communication method according to the present invention, on the transmitting side, a plurality of divided images are created by subsampling an original image in the same manner as in the first method, and general information source coding is performed for each divided image. Is performed, one or more preselected ones of the divided images are classified as a divided image A, and the remaining divided images are classified as a divided image B, and each divided image is subjected to error detection coding and transmitted, and divided on a receiving side. If an error is detected in the transmission data of the image A, the data is retransmitted. If an error is detected in the transmission data of the divided image B, the data is discarded and replaced with the substitute data. The encoded data or the substitute data of the normally received divided image B is decoded by the information source and reproduced, the reproduced image data of the divided image is synthesized, and the image data of the discarded part of the divided image B is further divided into surroundings. Image data received normally Interpolated from to obtain a reproduced image of the original image, a part of the divided images with high correlation with each other is reliably transmitted by retransmission, and the remaining part is discarded without retransmission even if an error occurs, Since interpolation is performed from the surrounding image data after the synthesis, it is possible to reduce the retransmission frequency and to transmit an image efficiently in a short time while maintaining a certain degree of accuracy even on a communication channel having a high error rate.

First, the configuration of an image communication apparatus for realizing the second image communication method according to the present invention will be described with reference to FIG. FIG. 4 is a block diagram showing the configuration of an image communication apparatus for realizing the second image communication method according to the present invention. In addition, FIG.
Parts having the same configuration as 10 will be described with the same reference numerals.

As shown in FIG. 4, an image communication apparatus (second apparatus) for realizing the second image communication method according to the present invention comprises a discrete cosine converter
, A quantizer 2, a Huffman encoder 3, and a modulator 6, and as a characteristic part of the present invention, a communication control unit 4b having therein an error detection encoder 5 similar to the conventional one.
And an image divider 13 similar to that of the first device.

The receiving side has a demodulator 7, a Huffman decoder 10, an inverse quantizer 11, and an inverse discrete cosine transformer 12, which have the same configuration as the conventional one. As a characteristic part, a communication control unit 8b having an error detection decoder 9 similar to the related art inside, and an interpolator 15
And an image synthesizer 14 similar to the first device.

Next, each part of the second device will be described in detail. The discrete cosine transformer 1, the quantizer 2,
Huffman encoder 3, error detection encoder 5, modulator 6, demodulator 7, error detection decoder 9, Huffman decoder 10, inverse quantizer 11, inverse discrete cosine The converter 12 is exactly the same as the conventional one, and the image divider 13 and the image synthesizer 14 are completely the same as the first device.
Only the parts different from the above device will be described.

The communication control section 4b controls communication on the transmission side. Specifically, the communication control section 4b receives coded data in block units from the Huffman coder 3, and outputs divided image data in the order of coded blocks. It is determined whether the divided image A is the divided image B or not, and the encoded data of the divided image A is error-detection encoded by the error detection encoder 5 as it is, and the HDLC frame is encoded in one or an arbitrary number of encoding units. Create and Modulator 6
And store it in preparation for retransmission. Then, when a retransmission command is received from the receiving side, the frame is retransmitted.

The coded data of the divided image B is added with position information (such as a number) indicating the position of the coding unit in the image, and is error-detected and coded by the error-detection coder 5. A transmission frame is created in one coding unit and output to the modulator 6.

When receiving the encoded data of the divided image demodulated from the demodulator 7, the communication control unit 8 b performs error detection decoding by the error detection decoder 9 and converts the normally received information source encoded data into Huffman data. The image is output to the decoder 10, and if an error is detected, it is determined whether the image is the divided image A or the divided image B based on the presence or absence of the position information. In the case of the divided image A, the retransmission command of the retransmission request is demodulated. Is transmitted from the transmitter 7 to the transmitting side.

On the other hand, when the error is detected in the divided image B, the data of the frame is discarded, and specific data (alternative data) prepared in advance is output to the Huffman decoder 10. The position information of the coded block (error block) included in the frame in which the error is detected is output to the interpolator 15 as error block information.

After interpolating the divided image A and the divided image B, the interpolator 15 detects the error in the encoded data of the divided image B, discards it, and decodes the part decoded by the substitute data.
It interpolates the surrounding normally received image data and outputs reproduced image data of the original image.

Specifically, an internal memory (first memory) capable of storing image data for one screen in the interpolator 15;
And an internal memory (second memory) for storing error block information. When the synthesized image data is output from the image synthesizer 14, the image data is captured and stored in the first memory.
When the erroneous block information is output from the communication control unit 8b, the erroneous block information is fetched and stored in the second memory. Based on the erroneous block information stored in the second memory, an error in the restored image data in the first memory is determined. When the interpolation is completed for all the error block information stored in the second memory, the reproduced image data is output from the first memory to the outside.

For example, assuming that the image division by the image divider 13 is divided into two in the vertical direction, the divided image A is reliably received by retransmission, an error occurs in the divided image B, and the divided image B is replaced with substitute data. When the image data is decoded by the information source and synthesized by the image synthesizer 14, as shown in FIG. 5, the image data replaced by the error (the gray part in FIG. 5) becomes every other line, and during that time the normal reception is always performed. The image data of the divided image A is arranged. FIG. 5 is an explanatory diagram showing an erroneous portion of an image after combination in the second device of the present invention.

As a specific interpolation method in the interpolator 15, a commonly known bilinear interpolation method or a simple method of copying pixel values of adjacent blocks may be used. Any method may be used as long as the interpolation method is selected depending on the processing speed and the interpolation accuracy until the curve interpolation is performed.

Here, an example of the interpolation processing will be described with reference to FIG. FIG. 6 is an explanatory diagram showing an example of the interpolation processing method in the image communication device according to the present invention. In an example of the interpolation processing method, the pixel value x of the portion where the error occurs in the divided image B (the gray portion in FIG. 6) is calculated by using the pixel values a, b, c, and d of the four surrounding pixels that are normally received. Equation 1].

[0069]

(Equation 1)

The correspondence between the components of the second embodiment described above and the respective means of the fourth embodiment is determined by the image divider 13
Corresponds to an image dividing unit, the discrete cosine transformer 1, the quantizer 2, and the Huffman encoder 3 correspond to an encoding unit, the communication control unit 4b and the modulator 6 correspond to a transmitting unit,
The demodulator 7 and the communication control unit 8b correspond to a receiving unit, the Huffman decoder 10, the inverse quantizer 11, and the inverse discrete cosine transformer 12 correspond to a decoding unit, and the image combiner 14 corresponds to an image combining unit. That is, the interpolator 15 corresponds to the interpolation means.

Next, the operation of the second image communication apparatus according to the present invention will be described with reference to FIG. Second embodiment of the present invention
When image data of an image (original image) to be transmitted to the transmission side is input, the image communication device of the third embodiment performs subsampling by the image divider 13 as in the first device, and performs discrete cosine transform for each divided image. 1, the information source is coded by the quantizer 2 and the Huffman coder 3, and the coded data is output to the communication control unit 4b. Then, one or more divided images among the predetermined divided images are referred to as a divided image A, and the remaining divided images are referred to as a divided image B.

The communication controller 4b determines whether the encoded data of the divided image output from the Huffman encoder 3 is the divided image A or the divided image B according to the order, and determines the code of the divided image A. The encoded data is sent to the error detection encoder 5
, An HDLC frame is created, modulated by the modulator 6 and transmitted.

On the other hand, the coded data of the divided image B is subjected to error detection coding by the error detection coder 5 by adding the position information of the coded block, and an HDLC frame is created and modulated by the modulator 6. Sent.

Then, on the receiving side, the data transmitted through the communication path is demodulated by the demodulator 7 and the error is detected by the error detecting and decoding unit 9 of the communication control unit 8a by following the reverse process of the transmitting side. The normally received encoded data is output to the Huffman decoder 10.

On the other hand, if an error is detected, the divided image A and the divided image B are discriminated from the presence or absence of the position information. In the case of the encoded data of the divided image A, a retransmission request is sent from the demodulator 7 to the transmitting side. It is transmitted and retransmitted by the communication control unit 4b.

In the case of the encoded data of the divided image B, the received data is discarded, the substitute data is output to the Huffman decoder 10, and the position information is output to the interpolator 15 as the error block information. .

Then, the encoded data of the normally received divided image A and the encoded data or the substitute data of the normally received divided image B are transmitted to the Huffman decoder 1 in the same manner as in the prior art.
0, the information is decoded by the inverse quantizer 11 and the inverse discrete cosine transformer 12, and the decoded image data is
Is output to

Then, the image synthesizer 14 rearranges the decoded image data of the divided images to synthesize the original image, and outputs the restored image to the interpolator 15 as a restored image.
Then, interpolation of the image data of the portion discarded in the divided image B and decoded with the substitute data based on the error block information is performed, and reproduced image data of the original image is output.

As in the first image communication method, how many divided images are divided by the image divider 13 and how many divided images among the divided images are to be treated as the divided image A are set in advance. The number of divisions and the number of divided images A are determined depending on whether the importance of accuracy of a reproduced image or reduction of communication time is emphasized. For example, if the number of divided images A is reduced by increasing the number of divisions, the reproduction accuracy is reduced, but the reproduction frequency is reduced and the communication time can be reduced.

FIG. 7 shows a comparison between the case of transmitting an image using the second image communication method of the present invention and the conventional method in relation to the error rate of the communication path and the communication time. To
In the case of the image communication method of the present invention, when the error rate is small, the communication time becomes longer by the amount corresponding to the position information of the divided image B than in the conventional method. It can be seen that the retransmission frequency is reduced because the number of target coded data is small, and the communication time is considerably shortened.
FIG. 7 is an explanatory diagram illustrating a relationship between an error rate of a communication path and a communication time.

According to the second image communication method and the second image communication apparatus of the present invention, the original image is divided on the transmission side, error detection decoding is performed on some of the divided images, and the coded data having an error is Retransmitted, the remaining divided images are error-detection coded and transmitted, the coded data with errors are discarded and replaced with alternative data, and the retransmitted divided image and the error portion are replaced with alternative data. Since the replaced divided image is decoded and the divided image is synthesized to create a restored image, there is an effect that the retransmission frequency can be greatly reduced and the transmission efficiency can be improved.

Further, since the portion replaced with the substitute data is interpolated from the surrounding normally received portion after the synthesis of the divided images, it is possible to maintain a certain degree of accuracy even on a communication path having a high error rate. is there.

Next, an image communication method according to a third embodiment, which differs from the first and second image communication methods and can greatly reduce the communication time, will be described with reference to the drawings.

In a third image communication method according to the present invention, a plurality of divided images are created by subsampling on the transmitting side in the same manner as in the first method, and general information source coding is performed for each divided image. Performing error detection coding and transmitting one or more preselected ones of the divided images as the divided image A, transmitting the remaining divided images as the divided image B with error correction coding,
When an error is detected in the transmission data of the divided image A on the receiving side, the data is discarded and replaced with the substitute data, the error correction decoding is performed on the divided image B, and the encoded data or the substitute data of the normally received divided image A, The encoded data of the divided image B subjected to the error correction decoding is decoded by the information source and reproduced, the reproduced image data of the divided image is combined, and the image data of the discarded portion of the divided image A is replaced with the surrounding normal data. Interpolation from the received image data to obtain a reproduced image of the original image, a part of the divided images having high correlation with each other is discarded if an error occurs, and the other part is efficiently transmitted by error correction coding, By interpolating the part discarded after combining, even if the communication path has a high error rate, retransmission is not performed and the communication time can be significantly reduced, and some accuracy can be maintained by interpolation. .

First, the configuration of an image communication apparatus for realizing the third image communication method according to the present invention will be described with reference to FIG. FIG. 8 is a block diagram showing the configuration of an image communication apparatus for realizing the third image communication method according to the present invention. In addition, FIG.
Portions having the same configuration as in FIGS. 4 and 10 are described with the same reference numerals.

As shown in FIG. 8, an image communication apparatus (third apparatus) for realizing a third image communication method according to the present invention includes a discrete cosine converter
, A quantizer 2, a Huffman encoder 3, and a modulator 6. Further, as a characteristic part of the present invention, in addition to the image divider 13 and the conventional error detection encoder 5, error correction is performed. A communication control unit 4c having an encoder 16 therein is provided.

The receiving side has a demodulator 7, a Huffman decoder 10, an inverse quantizer 11, and an inverse discrete cosine transformer 12, which have the same configuration as the conventional one. As a characteristic part, the conventional error detection decoder 9
In addition, a communication control unit 8c having an error correction decoder 17 inside, an image synthesizer 14, and an interpolator 15 are provided.

Next, each part of the third apparatus will be described in detail. The discrete cosine transformer 1, the quantizer 2,
Huffman encoder 3, error detection encoder 5, modulator 6, demodulator 7, error detection decoder 9, Huffman decoder 10, inverse quantizer 11, inverse discrete cosine The converter 12 is exactly the same as the conventional one, the image divider 13 and the image synthesizer 14 are exactly the same as the first device, and the interpolator 15 is completely the same as the second image communication device. Therefore, the description is omitted here, and only the portions different from the conventional device and the first and second devices will be described.

The communication control section 4c controls communication on the transmission side. Specifically, the communication control section 4c receives coded data in block units from the Huffman coder 3, and outputs divided image data in the order of the coded blocks. It is determined whether the divided image A is a divided image B or not, and information indicating a position in the image (position information such as a number) is added to the encoded data of the divided image A. Error detection encoding is performed, an HDLC frame is created in information source encoding units, and output to the modulator 6.

The coded data of the divided image B is error-correction-coded by the error-correction coder 16 and one or a plurality of information source coding units are put together, as in the first device. As shown in FIG. 2, a transmission frame to which a synchronization header is added is created and output to the modulator 6.

When receiving the coded data of the demodulated divided image from the demodulator 7, the communication control unit 8c determines whether the image is the divided image A or the divided image B by the synchronization header, and The encoded data is subjected to error detection decoding by the error detection decoder 9, and the normally received encoded data is output to the Huffman decoder 10.

If an error is detected, the data of the frame is discarded, and specific data (alternative data) prepared in advance is output to the Huffman decoder 10. The included position information is output to the interpolator 15 as error block information.

On the other hand, the encoded data of the divided image B is subjected to error correction decoding by the error correction decoder 17, and the encoded data is output to the Huffman decoder 10.

The correspondence between the components of the third embodiment described above and the respective means of the sixth embodiment is determined by the image divider 13
Corresponds to an image dividing unit, the discrete cosine transformer 1, the quantizer 2, and the Huffman encoder 3 correspond to an encoding unit, the communication control unit 4c and the modulator 6 correspond to a transmitting unit,
The demodulator 7 and the communication control unit 8c correspond to a receiving unit, the Huffman decoder 10, the inverse quantizer 11 and the inverse discrete cosine transformer 12 correspond to a decoding unit, and the image combiner 14 corresponds to an image combining unit. That is, the interpolator 15 corresponds to the interpolation means.

Next, the operation of the third image communication apparatus according to the present invention will be described with reference to FIG. 8, focusing on the difference from the first apparatus. The operation of the third image communication apparatus of the present invention on the transmitting side is almost the same as that of the first apparatus, but different points are as follows.
The point is that error detection encoding is performed after adding position information indicating the position in the image to the encoded data of the divided image A.

Hereinafter, the operation of the third device on the receiving side will be described. On the receiving side, the data transmitted through the communication path is demodulated by the demodulator 7 by following the reverse process of the transmitting side.
The communication controller 8c determines the divided image A and the divided image B from the synchronization header.

When the encoded data of the divided image A is received normally, the encoded data is converted to the Huffman decoder 10.
When the error is detected by the error detection decoder 9, the received data is discarded, the substitute data is output to the Huffman decoder 10, and the position information is output to the interpolator 15 as error block information. Is done.

On the other hand, the encoded data of the divided image B is subjected to error correction decoding by the error correction decoder 17 and output to the Huffman decoder 10.

Then, the encoded data or the substitute data of the normally received divided image A and the normally received divided image B
Is encoded by the Huffman decoder 1 as in the prior art.
0, the information is decoded by the inverse quantizer 11 and the inverse discrete cosine transformer 12, and the reproduced image data of the divided image is output to the image synthesizer 14.

Then, the reproduced image data of the divided images are rearranged in the image synthesizer 14 to synthesize the original sequence of images, and are output to the interpolator 15 as a restored image.
, The discarded portion of the image data is interpolated based on the error block information, and the reproduced image data of the original image is output.

FIG. 9 shows a comparison between the case of transmitting an image using the third image communication method of the present invention and the conventional method in relation to the error rate of the communication path and the communication time. To
In the case of the image communication method of the present invention, since no retransmission is performed, the communication time is constant irrespective of the error rate. The time gets longer. However, it can be seen that the communication time is considerably shorter in a place where the error rate is large, because there is no retransmission as compared with the conventional method. FIG.
FIG. 3 is an explanatory diagram showing a relationship between an error rate of a communication channel and a communication time.

According to the third image communication method and the third image communication apparatus of the present invention, an original image is divided on the transmission side, and some of the divided images are transmitted by error detection coding, and a code having an error is transmitted. Discard the coded data, decrypt the information source with the substitute data,
The remaining divided images are transmitted after being subjected to error correction coding, so that retransmission is not performed at all, so that the communication time can be significantly reduced even on a communication path with a high error rate, and the transmission efficiency can be greatly improved. effective.

Further, since the part discarded due to the error is interpolated from the surrounding normally received or error-corrected image data after the synthesis of the divided image, a certain degree of accuracy can be obtained even on a communication path having a high error rate. There is an effect that can be maintained.

According to the first aspect of the present invention, of the plurality of divided images obtained by sub-sampling the original image, the divided image A
Performs information source coding, error detection coding and transmission,
An error is retransmitted, the divided image B is subjected to information source coding, error correction coding is transmitted, and the receiving side decodes the information source to rearrange the pixels to reproduce the original image. Therefore, there is an effect that an image can be efficiently transmitted in a short time while the retransmission frequency is reduced and a certain degree of accuracy is maintained even on a communication path having a high error rate.

According to the second aspect of the present invention, the image dividing means creates a plurality of divided images by sub-sampling the original image, and the encoding means compresses and encodes the image data of the divided images to obtain the encoded data. And the transmitting unit classifies the divided images into a preselected divided image A and the remaining divided images B. The encoded data of the divided image A is error-detection encoded and transmitted, and the code of the divided image B is transmitted. The divided data is transmitted after being subjected to error correction coding, the receiving means receives the transmitted data, separates the divided image A and the divided image B, and retransmits the divided image A when an error is detected. For B, error correction is performed, and the decoding means expands and decodes the normally received divided image A and the error-corrected divided image B, and reproduces the divided image A and the divided image B. Rearrange the pixels Therefore, the image communication apparatus reproduces the original image, so that even if the communication path has a high error rate, the frequency of retransmission can be reduced, and the image can be transmitted efficiently in a short time while maintaining a certain degree of accuracy. .

According to the third aspect of the present invention, a plurality of divided images obtained by sub-sampling the original image are subjected to information source coding, error detection coding and transmission, and the error of the divided image A is retransmitted and divided. The error of the image B is discarded, the information source is decoded, the pixels are rearranged, and the discarded portion is interpolated from the surroundings to reproduce the original image. This also has the effect of efficiently transmitting images in a short time while reducing the retransmission frequency and maintaining a certain degree of accuracy.

According to the fourth aspect of the present invention, the image dividing means creates a plurality of divided images by sub-sampling the original image, and the encoding means compresses and encodes the image data of the divided images to obtain the encoded data. And the transmitting unit classifies the divided images into a preselected divided image A and the remaining divided images B. The encoded data of the divided image A is error-detection encoded and transmitted, and the code of the divided image B is transmitted. The encoded data is transmitted after being subjected to error detection coding by adding position information, and the receiving means receives the transmitted data and separates the divided image A and the divided image B. If an error is detected for the divided image A, The retransmission is performed, and if an error is detected for the divided image B, it is discarded, error block information indicating an error position in the image is output, and the decoding unit receives the divided image A and the divided image B that are normally received. Decompress and decode The pixels are rearranged from the divided image A and the divided image B reproduced by the image synthesizing unit, and the interpolating unit determines the discarded image part in the rearranged image data based on the error block information. An image communication device that reproduces the original image by interpolating from the image data, reducing the frequency of retransmission even on a communication path with a high error rate, and transmitting images efficiently in a short time while maintaining a certain level of accuracy. There is an effect that can be done.

According to the fifth aspect of the present invention, among the divided images obtained by sub-sampling the original image, the divided image A is subjected to information source encoding, error detection encoding and transmission, and errors are discarded and divided. Image communication is performed by performing information source coding, performing error correction coding, transmitting the data, decoding the information source at the receiving side, rearranging the pixels, and interpolating the discarded portion from the surroundings to reproduce the original image. Since the method is used, even if the communication path has a high error rate, the transmission time is greatly reduced without performing retransmission, and the image can be transmitted with some accuracy by interpolation.

According to the sixth aspect of the present invention, the image dividing means creates a plurality of divided images by sub-sampling the original image, and the encoding means compresses and encodes the image data of the divided images to obtain the encoded data. And the transmitting unit classifies the divided images into a preselected divided image A and the remaining divided images B. The encoded data of the divided image A is error-detection encoded and transmitted, and the code of the divided image B is transmitted. The encoded data is transmitted after being subjected to error correction coding, and the receiving means receives the transmitted data, separates the divided image A and the divided image B, and discards an error in the divided image A when an error is detected. And outputs error block information indicating an error position in the divided image B, performs error correction on the divided image B, and decodes and decodes and reproduces the normally received divided image A and the error-corrected divided image B, Image synthesis means Pixels are rearranged from the reproduced divided images A and B, and the interpolating means interpolates the discarded image part in the rearranged image data from the surrounding image data based on the error block information to obtain the original image. Since it is an image communication device that reproduces images, it does not perform retransmission even on a communication path with a high error rate, greatly shortens the communication time, and has the effect of transmitting images with some accuracy by interpolation. is there.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an image communication device that implements a first image communication method according to the present invention.

FIG. 2 is an explanatory diagram showing a transmission frame format of a divided image B subjected to error correction coding in the first image communication device of the present invention.

FIG. 3 is an explanatory diagram showing a relationship between an error rate of a communication channel and a communication time.

FIG. 4 is a block diagram illustrating a configuration of an image communication device that implements a second image communication method according to the present invention.

FIG. 5 is an explanatory diagram showing an erroneous portion of an image after combination in the second device of the present invention.

FIG. 6 is an explanatory diagram showing an example of an interpolation processing method in the image communication device of the present invention.

FIG. 7 is an explanatory diagram illustrating a relationship between an error rate of a communication path and a communication time.

FIG. 8 is a block diagram illustrating a configuration of an image communication device that implements a third image communication method according to the present invention.

FIG. 9 is an explanatory diagram showing a relationship between an error rate of a communication path and a communication time.

FIG. 10 is a configuration block diagram of a conventional JPEG image communication device.

FIG. 11 is an explanatory diagram showing a transmission frame format of the HDLC procedure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Discrete cosine transformer, 2 ... Quantizer, 3 ... Huffman encoder, 4, 4 ', 4a, 4b, 4c ... Communication control part, 5 ... Error detection encoder, 6 ... Modulator, 7 ...
Demodulator, 8, 8 ', 8a, 8b, 8c ... communication control unit,
9: error detection decoder, 10: Huffman decoder, 1
1: Inverse quantizer, 12: Inverse discrete cosine transformer, 1
3 image divider 14 image synthesizer 15 interpolator

Claims (6)

[Claims] 1. A transmitter performs sub-sampling for arranging a group of original image data of one frame of an original image by a quotient and a remainder obtained by dividing a pixel number of a pixel by an integer, and performs a plurality of sub-sampling from the original image. Form a divided image and select a pre-selected 1
The divided image A is divided into one or a plurality of divided images, and the remaining divided image is a divided image B. The divided image A is subjected to information source coding, error detection coding and transmission, and B performs information source coding, performs error correction coding, transmits the divided image A, and retransmits the divided image A when an error is detected, and decodes and reproduces the information source upon normal reception. For the divided image B, the information source is decoded and the information source is decoded and reproduced, and the reproduced divided image A and the divided image B are rearranged in the reverse manner of the sub-sampling to reproduce the original image. An image communication method, comprising: 2. An image dividing means for sub-sampling one frame of original image data of an original image to create a plurality of divided images from the original image, and compression-encoding the image data of the divided image to generate encoded data. Encoding means for creating, and classifying the divided images into one or more pre-selected divided images A and B, which are the remaining divided images, and encoding the divided images A The data is transmitted by error detection encoding, the encoded data of the divided image B is transmitted by error correction encoding and transmitted, and the transmitted data is received and separated into a divided image A and a divided image B, When an error is detected in the coded data of the divided image A, retransmission is performed, and in the coded data of the divided image B, error correction is performed. Decoding means for decompressing and decoding the encoded data of the divided image B and the error-corrected divided image B, and reordering the pixels from the reproduced divided image A and the divided image B by the reverse method of the sub-sampling. And an image synthesizing means for reproducing an original image. 3. The transmitting side performs sub-sampling of arranging the original image data of one frame of the original image in a group by a quotient and a remainder obtained by dividing the pixel number of the pixel by an integer, and performs a plurality of sub-sampling from the original image. Form a divided image and select a pre-selected 1
One or more divided images are divided into divided images A and the remaining divided images are divided images B. The divided images A and the divided images B are each subjected to information source coding and error detection coding. On the receiving side, for the divided image A, when an error is detected, retransmission is performed. When the image is normally received, the information source is decoded and reproduced, and for the divided image B, an error is detected. In the case, discard the encoded data received normally and reproduce it by decoding the information source. Reconstruct the divided image A and the divided image B by rearranging the pixels in the reverse method of the sub-sampling. An image communication method, wherein an original image is reproduced by interpolating a discarded image portion in B from surrounding pixels. 4. An image dividing means for subsampling one frame of original image data of an original image to create a plurality of divided images from the original image, and compression-encoding the image data of the divided image to generate encoded data. Encoding means for creating, and classifying the divided images into one or more pre-selected divided images A and B, which are the remaining divided images, and encoding the divided images A A transmitting means for performing error detection encoding on the data and transmitting the encoded data of the divided image B, adding error detection encoding by adding position information and transmitting the data, and receiving the transmitted data and dividing the divided image A with the divided image A If the error is detected in the encoded data of the divided image A, retransmission is performed, and the divided image B
If an error is detected, the encoded data is discarded and error block information indicating an error position in the image is output.
Decoding means for decompressing and decoding the encoded data of the divided image B and the encoded data of the divided image B, and the reproduced divided image A
Image synthesizing means for rearranging the pixels of the divided image B in the reverse method of the sub-sampling, and discarding the image part of the divided image B in the rearranged image data into the error block information. Interpolating means for reproducing an original image by interpolating from surrounding image data based on the image data. 5. The transmitting side performs sub-sampling of arranging the original image data of one frame of the original image by grouping the pixel numbers of pixels by the remainder and the quotient by dividing the pixel number of the pixel by an integer, and performing a plurality of sub-sampling from the original image Form a divided image and select a pre-selected 1
The divided image A is divided into one or a plurality of divided images, and the remaining divided image is a divided image B. The divided image A is subjected to information source coding, error detection coding and transmission, and B performs information source coding, performs error correction coding, and transmits the divided image A. At the receiving side, discards the divided image A when an error is detected, and decodes and reproduces the information source upon normal reception. The divided image B is subjected to error correction, information source decoding and reproduction, and the reproduced divided image A and the reproduced image B are rearranged in the reverse order of the sub-sampling to rearrange the pixels. An image communication method, wherein an original image is reproduced by interpolating a discarded image portion from surrounding pixels. 6. An image dividing means for subsampling one frame of original image data of an original image to create a plurality of divided images from the original image, and compressing and encoding the image data of the divided image to generate encoded data. Encoding means for creating, and classifying the divided images into one or more pre-selected divided images A and B, which are the remaining divided images, and encoding the divided images A Data is transmitted with error detection encoding added with position information, and encoded data of the divided image B is transmitted with error correction encoding and transmission, and the transmitted data is received and divided with the divided image A. The image data is separated into images B, and if an error is detected, the encoded data of the divided image A is discarded, error block information indicating an error position in the image is output, and the encoded data of the divided image B is output. Receiving means for performing error correction, decoding means for decompressing and reproducing encoded data of the normally received divided image A and encoded data of the error-corrected divided image B, and An image synthesizing unit that rearranges the pixels of the image A and the divided image B in the reverse method of the sub-sampling; and discards the discarded image portion of the divided image A in the rearranged image data into the error block. An image communication device comprising: an interpolation unit that reproduces an original image by interpolating from surrounding image data based on information.