JPH11220732A - Image communication method, transmitter, receiver, image communication device, and image processing device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To prevent image quality degradation by restoring an image from adjacent overlapping blocks. SOLUTION: With respect to an original image 1 divided into blocks, an overlapping block creating section 2 overlaps adjacent blocks and encodes them by an encoder 3. The transmission frame creating unit 4 creates a transmission frame in which error correction codes are added to the coded data of the plurality of overlapping blocks, and transmits the transmission frame via the I / F 5 and the transmission path 6. The receiving side decodes the encoded data of the overlapped block except for the transmission frame in which the error cannot be corrected, and restores the image by averaging the overlapped portion.

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, a transmitter, a receiver, an image communication device, and an image processing device using an image coding method for dividing an image into blocks and coding each block. For example, it is applied to communication between image output devices used for a printer, a facsimile, and the like.

[0002]

2. Description of the Related Art As one of coding methods for efficiently coding an image signal, there is a block coding method in which an image is divided into a plurality of blocks and the blocks are coded for each block. A typical method for encoding an image signal in a block is the JPEG method. When transmitting an image at a high transmission rate, the influence of transmission errors increases, and it is necessary to take measures against code errors such as error detection and correction codes. Especially,
In the case of high-speed serial communication represented by IEEE1394 or the like, the above measures are important. In addition, when the signal is transmitted via an electromagnetic conversion system such as a magnetic recording system or a satellite communication line, the transmission quality is expected to deteriorate. Therefore, a measure against a code error is indispensable.

FIG. 18 shows a conventional image communication system proposed in Japanese Patent Application Laid-Open No. 8-331562. The original image is divided into pixel blocks, and encoded by a high-efficiency encoding method represented by the JPEG method. The size of the block is 8 × 8 pixels or 4 × 4 pixels. The coded blocks are combined into a plurality of units, added with an error detection and correction code, and transmitted to a transmission path.

[0004] As the transmission path, a wired / wireless communication medium such as a conductor cable, an optical fiber, a communication satellite, and a microwave can be considered. The transmission rate is several tens of kilobits / second to several tens of megabits / second, depending on the information amount, compression rate, and transmission time of the original image. In the case of high-speed serial communication represented by IEEE 1394 or the like, the speed is several hundred megabits / second.

[0005] On the receiving side, the data propagated through the transmission path is corrected by an error detection and correction code. The error-corrected data is decoded to restore the original image. A coded block including a transmission error that could not be corrected by the error detection and correction circuit is interpolated by replacing the coded block with an adjacent coded block.

As described above, in the above-described conventional example, when an uncorrectable transmission error occurs, the coding block is used as an interpolation processing unit. That is, a coded block having an error that cannot be coded and corrected is exchanged for each coded block. Therefore, when the size of the coding block is increased to some extent, the processing unit of the interpolation is increased, and the effect of the interpolation is reduced.

FIG. 19 shows an image coding method proposed in Japanese Patent Application Laid-Open No. 6-6613. One image block (for example, 8 × 8 pixels) is further divided into a plurality (4 in the illustrated example).
Sub-blocks). That is, the first encoded block (pixels marked with 〇), the second encoded block (pixels marked with △), the third encoded block (pixels marked with ▽), and the fourth encoded block (marked with □) Pixel). For example, even if error correction cannot be performed on the coded block indicated by 〇, since the coded blocks overlap, the coded block indicated by 〇 is averaged by decoding the decoded data of other coded blocks. Can be interpolated.

However, in the above-mentioned conventional method, since one block is re-divided into a plurality of blocks, there is a disadvantage that the number of coded blocks increases and it takes time for coding.

[0009]

As described above, the error correction method in the conventional image communication method has a problem that the image quality is deteriorated when a block in which error correction cannot be performed is interpolated by another block. In addition, there is a problem similar to the case where error correction is impossible even if a transmission block is lost.
In particular, as shown in FIG. 20, when an image transfer using IEEE 1394 is performed by a host and an electrophotographic printer, if an IEEE 1394 bus reset occurs during the image transfer, the image transfer is stopped during the bus reset. Therefore, data is lost and the image quality is degraded (for IEEE1394 bus, InterfaceApr. 1996
ppl14-123 CQ publisher).

In addition, as described above, in the conventional coding method, since one coding block is divided into a plurality of coding blocks, it takes a long time to perform coding and decoding. .

An object of the present invention is to provide an image communication method, a transmitter, a receiver, an image communication device, and an image processing device in which the image quality is prevented from being degraded by restoring an image from adjacent overlapping blocks. It is in.

[0012]

According to the first aspect of the present invention, an image is divided into a plurality of blocks, and adjacent blocks are overlapped to form an overlap block. The overlap block is encoded, the encoded data of the plurality of overlap blocks is combined into a transmission block, a transmission frame in which an error detection and correction code is added to the transmission block is created, and the transmission frame is transmitted from the transmission path. Performs error detection and correction of the transmission frame received via the transmission block, and when error detection and correction of the transmission frame are possible, decodes the image coded data of a plurality of overlapping blocks in the transmission block, and It is characterized in that a block of an image is restored from a wrap block.

According to the second aspect of the present invention, an image is divided into a plurality of blocks, an adjacent block is overlapped to form an overlap block, the overlap block is encoded, and the encoded plurality of blocks are encoded. The overlapping blocks are put together, a header consisting of block information of the overlapping blocks is added to form a transmission block, and a transmission frame in which an error detection and correction code is added to the transmission block is created and transmitted from a transmission path.
Perform error detection and correction of the transmission frame received through the transmission path, when the error correction of the transmission frame is possible,
Separating a plurality of overlapped blocks coded as headers from the transmission block, decoding image encoded data of the separated plurality of overlapped blocks, and obtaining information of the overlapped blocks from the headers And restoring an image block based on the block information.

In the third aspect of the present invention, the number of overlapping blocks in the transmission block is [M / N] (where the line width of the image is M, the block size is N × N,
[R] is an integer not exceeding R).

According to a fourth aspect of the present invention, when restoring the block of the image, the overlapped area is averaged.

According to a fifth aspect of the present invention, the block information includes information on an area that overlaps within the block and the number of times the area overlaps.

According to the sixth aspect of the present invention, there are provided means for dividing an image into a plurality of blocks, means for creating an overlap block by overlapping adjacent blocks, and means for encoding the overlap block. Means for combining the encoded data of the plurality of overlap blocks into a transmission block, and creating a transmission frame in which an error detection and correction code is added to the transmission block;
Means for transmitting the transmission frame via a transmission path.

According to the seventh aspect of the present invention, there is provided a means for detecting and correcting an error in a transmission frame received via a transmission path, and a method for detecting and correcting an error in the transmission frame when a plurality of overflows in the transmission block are possible. It is characterized by comprising means for decoding the image encoded data of the wrapped block, and means for restoring the image block from the decoded overlapped block.

According to the present invention, a means for dividing an image into a plurality of blocks, a means for creating an overlap block by overlapping adjacent blocks, and a means for encoding the overlap block are provided. Means for combining the encoded data of the plurality of overlap blocks into a transmission block, and creating a transmission frame in which an error detection and correction code is added to the transmission block;
Means for transmitting the transmission frame via the transmission path, means for performing error detection and correction of the transmission frame received via the transmission path, and means for performing error detection and correction of the transmission frame when the transmission frame is capable of error detection and correction. And a means for decoding image encoded data of a plurality of overlapping blocks, and a means for restoring an image block from the decoded overlapping blocks.

According to the ninth aspect of the present invention, there are provided means for dividing an image into a plurality of blocks, means for creating an overlap block by overlapping adjacent blocks, and means for encoding the overlap block. A plurality of encoded overlap blocks are combined, a header consisting of block information of the overlap blocks is added to form a transmission block, and a transmission frame in which an error detection and correction code is added to the transmission block is created. Means for transmitting the transmission frame via the transmission path, means for performing error detection and correction of the transmission frame received via the transmission path, and transmitting the transmission frame when error correction of the transmission frame is possible. Means for separating a plurality of overlapping blocks coded as headers from the block; Means for decoding the coded image data of the overlapping block, and means for obtaining the overlapped block information from the header and restoring the image block based on the block information. .

According to a tenth aspect of the present invention, there are provided a means for dividing an image into a plurality of blocks, a means for creating an overlap block by overlapping adjacent blocks, and a means for encoding the overlap block. A plurality of encoded overlap blocks are combined, a header consisting of block information of the overlap blocks is added to form a transmission block, and a transmission frame in which an error detection and correction code is added to the transmission block is created. Means for transmitting the transmission frame via the transmission path, means for performing error detection and correction of the transmission frame received via the transmission path, and transmitting the transmission frame when error correction of the transmission frame is possible. Means for separating a plurality of overlapping blocks coded as headers from the blocks; Means for decoding the image encoded data of the overlapped block, means for generating, based on the header, area information overlapping in the block and block information including the number of times the area overlaps; Means for restoring a block of an image based on the block information.

In the eleventh aspect of the present invention, the number of overlap blocks in the transmission block is [M / N] (where the line width of the image is M, the block size is N × N,
[R] is an integer not exceeding R).

According to a twelfth aspect of the present invention, when restoring a block of the image, the overlapped area is averaged.

According to the thirteenth aspect of the present invention, there are provided a means for dividing an image into a plurality of blocks, a means for creating an overlap block by overlapping adjacent blocks, and a means for encoding the overlap block. A plurality of encoded overlap blocks are combined, a header consisting of block information of the overlap blocks is added to form a transmission block, and a transmission frame in which an error detection and correction code is added to the transmission block is created. Means for transmitting the transmission frame via the transmission path, means for performing error detection and correction of the transmission frame received via the transmission path, and transmitting the transmission frame when error correction of the transmission frame is possible. Means for separating a plurality of overlapping blocks coded as headers from the blocks; Means for decoding the image encoded data of the overlapped block, means for generating, based on the header, area information overlapping in the block and block information including the number of times the area overlaps; And a means for restoring a block of an image based on the block information, and a means for outputting the restored image.

In the fourteenth aspect of the present invention, the number of overlapping blocks in the transmission block is [M / N] (where the line width of the image is M, the block size is N × N,
[R] is an integer not exceeding R).

According to a fifteenth aspect of the present invention, when restoring a block of the image, the overlapped area is averaged.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be specifically described below with reference to the drawings. <Embodiment 1> FIG. 1 shows the configuration of the transmitting side of the present invention. In the figure, reference numeral 1 denotes an original image divided into a plurality of blocks;
Is an overlap block creating unit that creates an overlap block by overlapping adjacent blocks, 3 is an encoder that encodes the overlap block, and 4 is a transmission block that collectively encodes a plurality of overlap blocks. And a transmission frame creation unit for creating a transmission frame by adding an error detection and correction code.
EEE1394 I / F, 6 is a transmission line such as a conductor cable.

Note that the above-described configuration uses an IE as a transmission path.
Although the case where an EE-compliant serial line is used has been described, the present invention is not limited to this, and a transmission line such as an optical fiber or a communication satellite may be used.

FIG. 2 is a diagram for explaining an overlap block according to the present invention. First, the original image 1 is divided into a plurality of blocks. In the example of FIG. 2, the original image is divided into 16 blocks. The size of each block is N pixels x
N pixels, for example, 8 pixels × 8 pixels or 4 pixels ×
4 pixels. FIG. 3 assigns block numbers (a to p) to each of the 16 blocks.

FIG. 4 shows areas when each block is divided into four parts, and the locations of the respective areas are identified by numbers 11 to 22. For example, an area obtained by dividing the block f into four is expressed as fll, f12, f21, and f22.

Now, the overlap block 0f of the block f of the present invention is composed of the block f and the blocks adjacent to the block f (a, b, c, e, g, i, j, k in FIG. 2).
Is formed by a square area having a length of の of the side (N / 2 pixels). That is, the overlap block 0f (the halftone dot portion in the figure) of the block f is a22, b21, b
22, c21, e21, f11, f12, g11, e2
2, f21, f22, g21, i12, j11, j2
2, k11.

The overlap block creation section 2 creates an overlap block for each block (a to p) as described above. However, blocks f, g,
Except for j and k, some peripheral blocks have no image. For example, as shown in FIGS.
When creating an overlapping block of block b or block b, there is an area without an image.
Insert (zero).

The encoder 3 encodes the overlap block by a high-efficiency image encoding method represented by JPEG. The transmission frame creation unit 4 collectively encodes the plurality of overlapped blocks as a transmission block (for example, sets four overlap blocks for one row as transmission blocks), and adds a header (transmission block) to the transmission block. No.) and an error detection and correction code are added to create a transmission frame. Therefore,
For example, when transmitting the blocks in each row of the image in FIG. 2 as a transmission frame, the transmission frame in the first row is composed of a header (block numbers a, b, c, d) + overlapping blocks (0a, 0b, 0c, 0d). ) Is the encoded data + error detection and correction code. On the transmitting side, the created transmission frame is transferred via the IEEE 1394 I / F 5 and the transmission path 6.

The number of overlapping blocks in the transmission block is within [M / N] (however, the line width of the image is M, the block size is N × N, and [R] is an integer not exceeding R). Therefore, an image can be restored even if one line of the overlap block is missing. Conversely, if the value exceeds this range, if a transmission block is lost, it may not be possible to interpolate an image from the overlapped block.

Next, the receiving side will be described. FIG.
2 shows a configuration of a receiving side of the present invention. In the figure, reference numeral 21 denotes an interface IEEE 139 capable of high-speed serial communication.
4 I / F, 22 is an error detection / correction unit provided inside the interface, 23 is a header separator that separates the transmission block into header and overlap block encoded data, and 24 is the overlap block encoded data. Buffer for storing, 25 a header buffer for storing the header,
26 is an image decoder, 27 is an overlap information generator for generating overlap information, 28 is an image block reconstructor for restoring an image block from the decoded overlap block, and 29 is an electrophotographic image output device It is a type printer. Note that an image communication device or an image processing device is configured by combining FIG. 1 and FIG.

On the receiving side, the transmission frame is transmitted at 1394 I /
The signal is received at F21, and error detection and correction is performed by the error detection and correction unit 22. When the error correction enable / disable signal, which is the output of the error detection / correction unit 22, can be corrected, the transmission block is input to the header separator 23. Transmission frames for which error correction is not possible are excluded.

The header separator 23 separates the encoded data of the header and the overlap block from the transmission block. The encoded data of the separated overlap block is stored in the buffer 24 and decoded by the image decoder 26. The separated headers are stored in the header buffer 25, and overlap information (overlap area information,
(Overlap number information, overlap missing information). On the receiving side, it is assumed that the size of the overlap block, that is, the number of areas is 16 in advance.

The overlap information generator 27 manages the area of the overlap block based on the header (transmission block number). In other words, it manages how many times the overlapping block area overlaps. Further, information on which overlap block area is missing (missing) is also managed.

FIG. 9 shows an example of the overlap information.
In the example of FIG. 9, there is no missing overlap block.
This is an example in which all overlapping blocks have been transferred.
The numbers (1 to 4) in the figure indicate how many times the areas divided into four in the block overlap. This overlap information is determined by the transferred overlap block. For example, the area f11 overlaps four times, and the areas a11 and d12 overlap once.

For example, if the transmitted transmission blocks include the overlap blocks 0e and 0f and the error correction cannot be performed,
e and 0f are missing. FIG. 10 shows overlap information when the overlap blocks 0e and 0f are missing.

Alternatively, the overlap block 0e,
Similarly, if an IEEE 1394 bus reset occurs during the transfer of 0f, it is also lost. FIG. 11 shows overlap information when the overlap blocks 0e, 0f, 0g, and 0h are missing. Overlap area information (coordinate position of the area) which is overlap information,
The number of times of overlap and overlap missing information (to make the data at the missing position zero) are sent to the image block restorer 28.

FIG. 8 shows the configuration of the image block reconstructor. Each area of the overlap block from the image decoder 26 is overlapped by an overlap block buffer 32, 33, 34, 35 by a distributor 31 based on the overlap area information.
It is distributed to. The overlapping block area of odd rows and odd columns is stored in the overlapping block buffer 32, and the overlapping block area of odd rows and even columns is stored in the overlapping block buffer 33. The even-row and odd-column overlap block area is stored in the overlap-block buffer 34, and the even-row and even-column overlap block area is stored in the overlap-block buffer 35. The distribution to the buffer is performed four times.

If the overlap block is missing due to the overlap missing information at the time of distribution, null data (zero) is allocated to a predetermined overlap block buffer based on the overlap area information. Further, the value of a counter (not shown) is compared with the number of overlaps, and when the number of overlaps is smaller than the counter value, null data is allocated to an overlap block buffer corresponding to the overlap area.

Overlap block buffer 3
The data of 2, 33, 34, and 35 are added by the adder 36 based on the overlap area information. The data added by the adder 36 is divided by the divider 37 by the number of overlaps (sum of the number of times in the block) based on the overlap area information. The overlap area is averaged by the adder 36 and the divider 37, and the averaged data is sent to the line buffer 38 and transferred in synchronization with the printer 29 to output an image.

The operation will be described by taking the processing of the overlap block 0a as an example. The value of a counter (not shown) is set to 1, and data is stored in the buffer for the first time.
First, the number of overlaps in the overlap block area a11 is compared with the counter value. Since the number of overlaps (= 1) is equal to or greater than the counter value, the decoded data in the area a11 is stored in the overlap block buffer 32. Is stored in Since the number of overlaps (= 2) of the area a12 is equal to or larger than the counter value, the data of the area a12 is stored in the buffer 33.
The data of 1 is stored in the buffer 34, and the data of the area 22 is stored in the buffer 35.

Hereinafter, the stored data is referred to as (a1
1, a12, a21, 22).

Next, the value of the counter is set to 2, and
The same process of storing data in the buffer is performed. That is,
Since the number of overlaps (= 1) of the overlap block area a11 is equal to or less than the counter value, the buffer 32
Stores 0 (null data). Since the number of overlaps in the area a12 is 2, the data in the area a12 is stored in the buffer 33, the data in the area 21 is stored in the buffer 34, and the data in the area 22 is stored in the buffer 35.

By this processing, (0, a12, a21, a22) is further stored in the buffer.

When the counter value is set to 3 and the third storage processing to the buffer is performed in the same manner, (0, 0, 0, a2
2) is stored, the counter value is set to 4, and the fourth storage processing to the buffer is performed in the same manner, whereby (0, 0, 0,
a22) is stored.

Therefore, (a11, 0,
(0, 0) is stored in the buffer 33 (a12, a1).
2,0,0) is stored in the buffer 34 (a21,
a21,0,0) is stored in the buffer 35 (a2,0,0).
2, a22, a22, a22) are stored.

When the data in the buffer is added by the adder 36, a11 + 2 × a12 + 2 × a21 + 4 × a22 is output.

In the divider 37, the addition result is divided by the sum of the number of overlaps, and (a11 + 2 × a12 + 2 × a21 + 4 × a22) / 9 The averaged data is output to the line buffer 38 as the data of the block a. .

The counter is set to 1 again, and the next overlap block 0b is processed in the same manner as described above.

Further, as shown in FIG. 11, even if one row of overlap blocks is missing, the missing data includes the overlap blocks 0a to 0d and the overlap blocks 0i to 0l as described above. Restored by averaging.

<Embodiment 2> Next, Embodiment 2 of the present invention will be described. The second embodiment differs from the first embodiment in the configuration of the overlap block. The configurations on the transmitting side and the receiving side in the second embodiment use the configurations shown in FIGS. FIG. 12 illustrates an overlap block 0a according to the second embodiment. The overlap block 0a of the block a overlaps the blocks b, e, and f. The overlap block 0b of the block b overlaps the blocks c, f, and g. FIG. 13 shows the overlapping block 0 of the block b.
b, and is an area within the thick frame in the figure.

Similarly, the overlapping blocks 0e and 0f of the blocks e and f are shown by the regions within the thick frames in FIGS. 14 and 15, respectively. In the second embodiment, the overlap blocks are 0a, 0b, 0c, 0e, 0f, 0g, 0
Let i, 0j, 0k. Overlapping blocks (for example, 0d, 0h, etc.) protruding from the image are not created.
Thus, the overlap block of the present embodiment is 4
It consists of blocks.

The transmission frame encodes a plurality of overlap blocks (one row overlap block, three in this embodiment) by a high-efficiency image encoding represented by the JPEG system, and a header (transmission). A block number, for example, a, b, c) is added, and an error detection and correction code is further added. On the transmitting side, the created transmission frame is transferred by the IEEE 1394 I / F.

Next, the receiving side will be described.

As in the first embodiment, the 1394 I / F 21 is an interface capable of high-speed serial communication, and has an error detection / correction device 22 built in the interface. When the transmission frame is received by the 1394 I / F 21,
The error detection / correction unit 22 performs error detection / correction, and a transmission block in which an error correction enable / disable signal output from the error detection / correction unit 22 is not error-correctable is input to the header separator 23.

The coded data of the header and the overlap block are separated by the header separator 23, and the coded data of the separated overlap block is stored in the buffer 24 and decoded by the image decoder 26. Is done. The separated header is stored in the buffer 25, and the overlap information generator 27 generates overlap information. Here, it is assumed that the size of the overlap block is known in advance on the receiving side.

The overlap information generator 27 manages the overlap blocks from the header (transmission block number). That is, it manages which blocks overlap and how many times. Further, information on which block is missing (missing) is also managed.

FIG. 16 shows an example of the overlap information. FIG. 16 shows an example in which no overlap blocks are missing and all the overlap blocks are transferred. The numbers in the figure indicate how many times the blocks overlap. This overlap information is determined by the transferred overlap block.

Further, for example, the overlapped blocks 0e, 0f, and 0g are included in the transferred transmission block, and error correction of the transmission block cannot be performed, or an IEEE 1394 bus reset occurs during the transmission of the transmission block. If the overlap blocks 0e, 0f,
This means that 0 g was missing. FIG. 17 shows overlap information when the overlap blocks 0e, 0f, and 0g are missing. The overlap information includes the configuration information of the overlap block, the number of overlaps, and the overlap missing information, and is sent to the image block restorer 28.

The configuration of the first embodiment is used for the image block restoration unit 28. To explain the processing of the overlap blocks 0a and 0b, the block a is stored in the buffer 32,
The blocks b are stored in the buffers 33, respectively. Since the number of overlaps of the block a is one, the block a passes through the adder 36 and the divider 37 and is output to the line buffer 38. Next, the block b is added to the block b of the overlap block 0a and the block b of the overlap block 0b, divided by the number of overlaps of 2 and output to the line buffer 38. Hereinafter, similarly, the overlap blocks 0c and 0d are processed and output to the line buffer 38. The restored image stored in the line buffer 38 is transferred in synchronization with the electrophotographic printer 29, and the image is output.

Further, as shown in FIG. 17, even when the overlap blocks 0e, 0f, and 0g are missing, the missing blocks e, f, and g remain in the overlap block 0a.
0e and 0i to 0k.

In the above-described embodiment, the JPEG system is used as the image encoding and image decoding system. However, the present invention is not limited to this, and can be applied to other encoding systems other than the JPEG system. .

[0067]

As described above, claims 1 and 6,
According to the inventions described in (7) and (8), since an image is restored from an adjacent overlapping block, the image quality does not deteriorate even if the overlapping block in the transmission block is lost.

According to the second and ninth aspects of the present invention, since there is block information of an overlapped block as a header, it is possible to determine whether or not an overlapped block is missing. Since the image is restored from the block, the image quality does not deteriorate even if the overlap block in the transmission block is lost.

According to the third, eleventh and fourteenth aspects of the present invention, the number of overlapping blocks in the transmission block is:
Since it is within [M / N], an image can be restored even if one line of the overlap block is missing.

According to the fourth, twelfth and fifteenth aspects of the present invention, the overlapped areas are averaged, so that the blocks of the image can be restored.

According to the fifth and tenth aspects of the present invention, since the overlap area information and the number of times the overlap area overlaps are used as the block information, an image can be restored from the overlapped area.

According to the thirteenth aspect of the present invention, the missing overlap block is restored from the adjacent overlap block. Therefore, even when an electrophotographic printer which cannot stop printing is used as the image output means, the image can be reproduced. An image without deterioration can be output. Further, even if an IEEE 1394-compliant serial line is used as a transmission path, a lost overlap block is restored from an adjacent overlap block, so that an image without image deterioration can be transmitted or output.

[Brief description of the drawings]

FIG. 1 shows a configuration of a transmission side of the present invention.

FIG. 2 is a diagram illustrating an overlap block according to the present invention.

FIG. 3 shows the number of each block divided into 16 blocks.

FIG. 4 shows an area when each block is divided into four parts.

FIG. 5 shows an overlapping block of a block a.

FIG. 6 shows an overlapping block of a block b.

FIG. 7 shows the configuration of the receiving side of the present invention.

FIG. 8 shows a configuration of an image block restorer.

FIG. 9 shows a first example of overlap information.

FIG. 10 shows a second example of overlap information.

FIG. 11 shows a third example of overlap information.

FIG. 12 illustrates an overlap block 0a according to the second embodiment.

FIG. 13 illustrates an overlap block 0b according to the second embodiment.

FIG. 14 illustrates an overlap block 0e according to the second embodiment.

FIG. 15 illustrates an overlap block 0f according to the second embodiment.

FIG. 16 illustrates a first example of overlap information according to the second embodiment.

FIG. 17 illustrates a second example of overlap information according to the second embodiment.

FIG. 18 shows an example of the prior art.

FIG. 19 shows another example of the prior art.

FIG. 20 is a diagram illustrating an IEEE 1394 bus reset.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Original image 2 Overlap block creation part 3 Encoder 4 Transmission frame creation part 5, 21 IEEE1394 I / F 6 Transmission line 22 Error detection and correction device 23 Header separator 24 Buffer 25 Header buffer 26 Image decoder 27 Overlap information Generator 28 Image block decompressor 29 Electrophotographic printer

Claims (15)

[Claims] 1. An image is divided into a plurality of blocks, adjacent blocks are overlapped to form an overlap block, the overlap block is encoded, and encoded data of the plurality of overlap blocks is collected. A transmission frame is created by adding an error detection and correction code to the transmission block, transmitted from a transmission path, performing error detection and correction on the transmission frame received via the transmission path, and performing error detection on the transmission frame. An image communication method, characterized in that when correction is possible, image encoded data of a plurality of overlapping blocks in the transmission block is decoded and an image block is restored from the decoded overlapping blocks. 2. An image is divided into a plurality of blocks, an adjacent block is overlapped to form an overlap block, the overlap block is encoded, and the encoded overlap blocks are combined. Further, a header consisting of block information of the overlap block is added to form a transmission block, a transmission frame in which an error detection and correction code is added to the transmission block is created, transmitted from a transmission path, and transmitted through the transmission path. Error detection and correction of the received transmission frame are performed, and when error correction of the transmission frame is possible, a plurality of header-encoded overlapping blocks are separated from the transmission block, and the separated plurality of overlapping blocks are separated. Decodes the coded image data of the wrapped block and overlaps the block information from the header And reconstructing an image block based on the block information. 3. The number of overlapping blocks in the transmission block is [M / N] (however, the line width of the image is M, the block size is N × N, and [R] is an integer not exceeding R). The image communication method according to claim 1, wherein: 4. When restoring blocks of the image,
3. The image communication method according to claim 1, wherein the overlapping areas are averaged. 5. The image communication method according to claim 2, wherein the block information includes information on an area that overlaps in the block and the number of times the area overlaps. 6. A means for dividing an image into a plurality of blocks, a means for creating an overlap block by overlapping adjacent blocks, a means for encoding the overlap block, and the plurality of overlaps Means for generating a transmission frame in which the coded data of the blocks are combined into a transmission block, and adding an error detection and correction code to the transmission block; and means for transmitting the transmission frame via a transmission path. And the transmitter. 7. A means for performing error detection and correction of a transmission frame received via a transmission path, and image coding of a plurality of overlapping blocks in the transmission block when error detection and correction of the transmission frame are possible. A receiver comprising: means for decoding data; and means for restoring a block of an image from the decoded overlap block. 8. A means for dividing an image into a plurality of blocks, a means for creating an overlap block by overlapping adjacent blocks, a means for encoding the overlap block, and the plurality of overlaps Means for creating a transmission frame in which the coded data of the blocks are combined into a transmission block and adding an error detection and correction code to the transmission block; means for transmitting the transmission frame via a transmission path; Means for performing error detection and correction of the transmission frame received in the transmission block, and means for decoding image encoded data of a plurality of overlapping blocks in the transmission block when error detection and correction of the transmission frame are possible; Means for restoring a block of the image from the decoded overlap block. apparatus. 9. A means for dividing an image into a plurality of blocks, means for creating an overlap block by overlapping adjacent blocks, means for encoding the overlap block, and means for encoding the overlap block Means for combining a plurality of overlapping blocks, further adding a header consisting of block information of the overlapping blocks to form a transmission block, and creating a transmission frame in which an error detection and correction code is added to the transmission block; Means for transmitting over the transmission path, means for performing error detection and correction of the transmission frame received via the transmission path, and when the error of the transmission frame can be corrected, the header is removed from the transmission block. Means for separating a plurality of encoded overlap blocks, and the separated plurality of overlap blocks An image communication apparatus, comprising: means for decoding the image encoded data of claim 1; and means for obtaining overlapped block information from the header and restoring an image block based on the block information. . 10. A means for dividing an image into a plurality of blocks, means for creating an overlap block by overlapping adjacent blocks, means for encoding the overlap block, and means for encoding the overlap block. Means for combining a plurality of overlapping blocks, further adding a header consisting of block information of the overlapping blocks to form a transmission block, and creating a transmission frame in which an error detection and correction code is added to the transmission block; Means for transmitting over the transmission path, means for performing error detection and correction of the transmission frame received via the transmission path, and when the error of the transmission frame can be corrected, the header is removed from the transmission block. Means for separating the encoded plurality of overlap blocks, and the separated plurality of overlap blocks. Means for decoding image encoded data of a block, means for generating block information including area information overlapping in the block based on the header and the number of times the area overlaps, Means for restoring a block of an image based on the information. 11. The number of overlapping blocks in the transmission block is [M / N] (however, an image line width is M, a block size is N × N, and [R] is an integer not exceeding R). The image communication device according to claim 8, 9 or 10, wherein 12. When restoring a block of the image,
11. The image communication apparatus according to claim 8, wherein the overlapping areas are averaged. 13. A means for dividing an image into a plurality of blocks, a means for creating an overlap block by overlapping adjacent blocks, a means for encoding the overlap block, and a means for encoding the overlap block. Means for combining a plurality of overlapping blocks, further adding a header consisting of block information of the overlapping blocks to form a transmission block, and creating a transmission frame in which an error detection and correction code is added to the transmission block; Means for transmitting over the transmission path, means for performing error detection and correction of the transmission frame received via the transmission path, and when the error of the transmission frame can be corrected, the header is removed from the transmission block. Means for separating the encoded plurality of overlap blocks, and the separated plurality of overlap blocks. Means for decoding image encoded data of a block, means for generating block information including area information overlapping in the block based on the header and the number of times the area overlaps, An image processing apparatus comprising: means for restoring a block of an image based on information; and means for outputting the restored image. 14. The number of overlapping blocks in the transmission block is [M / N] (however, an image line width is M, a block size is N × N, and [R] is an integer not exceeding R). The image processing apparatus according to claim 13, wherein: 15. When restoring a block of the image,
14. The image processing apparatus according to claim 13, wherein the overlapped areas are averaged.