JPS61227482A - Picture information reproducing error processor - Google Patents

Abstract

PURPOSE:To reduce disturbance in a reproduced picture by using a data of a line just before in place of an erroneous data when a reproduction error exists. CONSTITUTION:A compression reproducing processing section 102 codes picture information received in an input line buffer 100 into the linear compression coding system such as the MH system, further the picture data subject to compression coding received in the input line buffer 100 is applied with the code reproduction to restore the original picture information, which is outputted to an output line buffer 104. The original picture 300 is subject to compression coding in the unit of two lines, and if a data with simultaneous coding to lines 3, 4 has an error, the compression reproducing processing section 102 uses a data of one line just before, that is, the data of the line 2 in place of the erroneous data on the lines 3,4 to restore the reproduced picture.

Description

[Detailed description of the invention] 11 missing! The present invention relates to an image information processing system, and more particularly to an image information reproduction error processing apparatus for processing errors in reproduction of one-dimensional compression-encoded image information such as in a facsimile machine.

For example, one-dimensional compression group encoding methods for image information, such as the Modified Huffman (MH) encoding method, are useful for transmitting image data in image information communication systems and storing image information in memory. It is effectively used to improve transmission or storage efficiency.

Such redundancy compression and reproduction of image information has generally been performed by an image information compression/reproduction device commonly connected to a central processing system (CPU) along with other devices via a system bus. Such an image information compression/reproduction device is
It occupied the position of a "slave unit" relative to the system bus, and was under the control of the CPU, sending and receiving control signals and transferring data.

Generally, many units other than this compression/reproduction device are connected to the system bus. Therefore, in order to improve the overall performance of the system so that it can handle a larger amount of image information at high speed, it is necessary to use the system bus more efficiently by shortening the processing time of each unit/unit connected to the system bus. required.

In the conventional system, for example, image information forming main scanning m (lines) in a raster scanning system is taken into a compression/reproduction device line by line, and redundancy compression or reproduction processing is performed. In such a method, even if the image data is short, that is, the number of dots per line is small and the storage capacity of the line data buffer provided in the compression/reproduction device has sufficient storage capacity, the input/output of image data to/from the compression/reproduction device is possible. Each time, the CPU had to frequently activate the system bus to perform processing. Therefore, the throughput of the CPU with respect to other units connected to the same bus has been relatively reduced.

Purpose The present invention solves the drawbacks of the prior art, and provides an image information reproduction error processing device which has high overall system performance, such as being able to process a larger amount of image information at high speed, and which causes less disturbance in reproduced images. The purpose is to provide.

In order to achieve the above object, the present invention provides an image that is one-dimensionally compressed and encoded in units of data of a plurality of successive predetermined main scanning lines included in image data formed by raster scanning of an original image. In an image information reproduction error processing device that encodes and reproduces data and processes errors in the encoded reproduction, an accumulation means for accumulating compression encoded image gaters.

code reproducing processing means for code reproducing the image data stored in the storage means, and when there is a reproduction error in code reproduction of the image data stored in the storage means, the code reproducing processing means is configured to reproduce the code including the error. The present invention is characterized by an image information reproduction error processing device that replaces the data of one main scanning line immediately before the data of a predetermined plurality of main scanning lines. Hereinafter, a detailed explanation will be given based on one embodiment of the present invention.

Referring to FIG. 1, an embodiment of the image information reproduction error processing apparatus according to the present invention is realized as a data processing system that can also handle image data as one of various data. This data processing system consists of a central processing unit (CPU) 1
system bus 12 connected to and controlled by
Other units 34 such as the program memory 14, data memo river B, image input interface 18, display control section 22, communication interface 2B, image information compression/reproduction section 32, image processing section, and image information memory 36 are connected to the . has been done.

The CPU 10 is a control device that supervises and controls the entire device according to the program stored in the program memory 14, and the data necessary for the control is stored in the data memory 16.
is stored in An input device 38 such as a keyboard is connected to the CPU 10.

An image scanner 20 is connected to the image input interface 18, and the scanner 20 is an image information input device that optically raster scans a visible image of a document to obtain a corresponding image information signal. This image information signal is output in the form of dot data consisting of n (natural number) pixels forming a horizontal scanning line, that is, a main scanning line (line).

The display control unit 22 is connected to an image display device 24 such as a CRT, and displays image information input by the scanner 20, data input from the input device fi 38, commands and data instructed by the operator from the CPU 10, etc. is visible here.

A communication line 28 such as a facsimile line, a communication line 30 to another data processing system, and the like are connected to the communication interface 2B, thereby allowing the present apparatus to transmit image information with other systems.

In this embodiment, the image information compression/reproduction unit 32 encodes the image information portion based on the raster scanning method among various data input to the system using a one-dimensional compression grouping system such as the MH method, It also has a function of encoding and reproducing the image data compressed and encoded in this way to recover the original image information. The image information data compressed and encoded in this manner is efficiently transmitted to one communication line 28 or 30, and is also efficiently stored in the image information memory 3B. Details of the configuration will be explained later with reference to FIG.

These image information are temporarily stored in a buffer area formed in a part of the data memory 1B, and are finally stored in the image information memory 38. Tapes and the like are advantageously applied.

Referring to FIG. 2, the configuration of the compression/reproduction section 32 is shown in relatively detail. The compression playback section 32 includes an input line buffer 10G, a compression playback processing section 102. Output line buffer 104. and a unit control section 10B.

Input line buffer 100 and output line buffer 1
04 are line data buffers that temporarily store unencoded image information dot data based on the raster scanning method or compression encoded image information data, and are connected to the data line 110 of the system bus 12. There is. Advantageously, each of these storage capacities is arranged over a number of dots forming a line of the largest document handled by the system. For example, it has a capacity that can store dots forming one line when the longitudinal direction of an A3 size image is taken as the main scanning direction.

The compression and reproduction processing unit 102 encodes the image information received in the input line buffer 100 using a one-dimensional compression group coding system such as the M1 method in this embodiment, and outputs this encoded data to the output line buffer 104. It also encodes and reproduces the compressed and encoded image data received in the input line buffer 10G to recover the original image information, and outputs this to the output line buffer 104. Furthermore, it has a function of processing errors in code reproduction of compression-encoded image data as described later to form a reproduced image with less disturbance.

The unit control section 10B includes data lines 110 . This is a control device that is connected to the address line 112 and the control line 114 and controls each part of the compression/reproduction section 32 in response to data, addresses, and control signals received therefrom. The data line 110 is a bus for transferring data such as image information, the address line 112 is a line for transferring device addresses, register addresses, storage location addresses, etc. of various units including the compression/reproduction section 32, and the control line 114 is a bus for transferring data such as image information. is the interrupt signal (
This line transfers various control signals such as INT).

According to the Bokuto style, image data is transferred to the input line buffer 100 in units of image data in an amount substantially equal to or close to the storage capacity of the input line buffer 100, and the compression reproduction processing unit 102 When the compression reproduction process for the image data stored in the 10G is completed, the CPU 10 is notified to that effect.

For example, as shown in FIG. 4, image data of N consecutive lines (for example, a natural number such as 2) of image information are collectively sent to the compression/reproduction unit 32, and the compression/reproduction unit 32 processes these eight lines. The data is taken as a unit and sequentially compressed and encoded. The encoded data is stored in memory 3B. Further, the compression-encoded data stored in the memory 3B is read out to the compression/reproduction unit 32 in units of the lines corresponding to the N tree, and is sequentially encoded and reproduced here. Therefore, the code-regenerated image information forms image data of N-tree lines. In this method, image information is managed in units of N lines within the system. This value N is
Considering the storage capacity of the input line buffer 100, the image data of N tree lines is set to a value that can be stored therein.

Alternatively, instead of managing N lines in units of data forming N tree lines, the number of unencoded image information data corresponding to the storage capacity of the input line buffer 100 may be collectively managed. The image information data is taken into the compression and playback unit 32, and the compression and playback unit 32 sequentially compresses and encodes it, and also takes the encoded image information data into the compression and playback unit 32 in units of dots corresponding to the storage capacity of the buffer 100. The latter method, which may be configured to perform code reproduction sequentially, does not use line management to handle image data line by line;
Line frames are excluded from processing of image data within the system.

As can be seen from FIG. 3, which shows the operational flow of the compression/reproduction processing unit program executed by the CPU to control the compression/reproduction unit 32 and stored in the program memory 14, the CPo 10 first performs the above-described operations. A processing mode for data processing is set (200). Document image information data of n dots per line is sequentially input to the system from the scanner 20.

In this embodiment, this image data is transferred to the compression/reproduction unit 32 for transmission or storage in units of 8947 minutes.
CPU TO then sets the number of transfer data to N lines in this example (202).

Therefore, the CPU 10 transmits this image data in units of 8947 minutes to the compression and reproduction unit 32 for transmission or storage.
(204), which is taken from data line 110 to input line buffer 100. When the transfer is completed, the CPU 10 enters an idle state waiting for an interrupt (LIT) from the compression/reproduction unit 32 (20B). Therefore, the CPU 10 cannot execute other jobs until an interrupt occurs. I can do it.

When 8947 worth of data is accumulated in buffer 100,
In the compression and reproduction section 32, the compression and reproduction processing section 102 sequentially reads out image information data from the input line buffer 100 under the control of the unit control section IH.

This is encoded by one-dimensional compression.

Compression encoded data is sequentially output to the line buffer 10
It is stored in 4. When the compression-encoded data corresponding to N lines is accumulated in the buffer 104, the unit control section 10B sends an interrupt flag (I) to the control line 114.
NT).

When the interrupt flag is set, the CPU 10 responds by interrupting other tasks at an appropriate point if they are currently being executed, and checks the logic of the processing results of the compressed and encoded image data (210). , if the processing result is correct, C
The PU 10 reads the encoded data from the output line buffer 104 (212) and stores it in the image information memory 3B.
If the 6-screen information data stored in the 6-screen information data or transmitted to the outside via the communication interface 2B is not the last page of the page containing it (214), the above operations are repeated until the end of the page is reached. .

In this embodiment, the CPU 10 is notified of the completion of processing in the compression/reproduction section 32 by an interrupt, but instead of one interrupt, a status register is provided, and this register is used to notify the CPU 10 of the completion of the compression or reproduction processing. Set and CPo 1
It may be configured to report to 0.

When the image data compressed and encoded in this manner is encoded and reproduced, the compression and reproduction section 32 operates in the same manner. In this case, encoded image data is transferred to the input line buffer 100 as described above.

Basically, the operation flow shown in FIG. 3 is applied as is, with the only difference being that this code is reproduced by the compression reproduction processing unit 102 and stored in the output line buffer 104.

The compression/reproduction processing section 102 processes code reproduction errors that occur during code reproduction in the following manner. For example, the data of the original picture 300 including the letter "A" as shown in FIG.
It is formed by a plurality of horizontal (main) scanning lines (lines) 302 . In the figure, for the sake of explanation, the original image 30G is composed of 8 lines, and the line numbers are indicated by # numbers on the left side.

The compression and reproduction processing unit 102 encodes and reproduces the data in which the original picture 300 is compressed and encoded in units of two lines. Suppose that the code has been read, or that an error has occurred in the code reproduction. The compression and reproduction processing unit 102 restores the reproduced image by substituting the data of the line cloud 3 and the atmosphere 4 containing such errors with the data of one line immediately before them, that is, the data of the line cloud 2. In other words, the compression/reproduction processing unit 102 always retains at least one line of data that immediately precedes the two lines of data currently undergoing code reproduction processing and has already undergone reproduction processing, and is designed to prevent errors in the former data. If it is included, use the latter data instead.

FIG. 6 shows a reproduced image 304 resulting from applying such error processing to the original image 30G.
4 data is substituted by using the data of line @2 twice. In the example shown in the figure, the scanning line density is shown very coarsely for the sake of explanation, so the portions subjected to error processing appear to be somewhat exaggerated. However, in an actual device, the resolution is much higher than this, so the image resulting from this error processing is hardly noticeable.

For comparison, in the conventional method that performs code reproduction on a line-by-line basis, for example, if there is an error in the data on line @3, the data on line @2 is substituted and the reproduced image 30B is generated. was forming.

In a system that encodes and reproduces two lines at once as in this embodiment, if the line cloud 3 containing an error,
If the data of cloud 4 is substituted with the data of the two-line cloud 1゜@2 immediately before it, an image 308 that is far different from the original image 300 will be reproduced, as shown in Figure @8. . However, the compression and reproduction processing section 10 of this embodiment
2 performs the above-mentioned reproduction error processing, so that the image 308 that is far different from the original image will not be reproduced.

By the way, when data is not handled in such an N-line management format, but image information data corresponding to the storage capacity of the input line buffer 100 is taken into the compression/reproduction unit 32 as a unit and compression encoding and code reproduction are performed. Also, the compression/reproduction section 32 operates in the same manner. In this case, as described above, an amount of image data substantially equal to or close to the storage capacity of the input line buffer 100 is transferred to the input line buffer 100, and this is compressed and encoded or encoded and reproduced by the compression and reproduction processing section 102. , are stored in the output line buffer 104. Basically, the operation flow shown in FIG. 3 can be applied as is, with the contents of the mode setting in step 200 and the contents of the number of data to be transferred in step 202 being slightly different from the above-mentioned example.

In conventional methods, when document image information, in which image data of n dots per line is formed by m lines, is input from an input device such as a scanner, the system uses line management to process this on a line-by-line basis. Generally, image information compression and reproduction apparatuses that handle image data have a line buffer that can store one line of image data, and in this example, each line is processed m times.

The storage capacity of a line buffer is generally configured to approximate the number of dots forming one line of the largest document handled by the system. Therefore, in the case of image information of a small document, only a portion of the storage capacity of the line buffer is stored, so although the amount of image data transferred at one time is small, the number of transfers per unit time is , and therefore the frequency of compression/reproduction processing increases. Since many other slave units are connected to the system bus to which the compression/reproduction device is connected, the throughput of the processing device with respect to these other units is reduced accordingly.

However, according to the embodiment of the present invention described above, whether compressing and reproducing is performed in units of image data for N trees of lines, or compressing and reproducing in units of data corresponding to the storage capacity of the line buffer, The number of data units processed by the compression/reproduction unit 32, ie, the number of virtual lines, is decreasing. Therefore, the CPU to executes the flow shown in FIG. 3 less frequently than in the conventional method.

In the operation flow shown in FIG. 3, compression processing is started once for each arrow indicated by numerals 130 and 132 in FIG. 4, and reproduction processing is started once for each arrow indicated by numerals 134 and 13B. Ru. Conventionally, a compression or regeneration flow is activated for each line individually.

Therefore, in the example shown in Figure 4, 1 of the number of startups in the conventional method
/2. As will be seen, the number of processing steps that the CPU 10 is involved in with the compression/reproduction unit 32, and thus the processing time thereof, is reduced. This will give you more time to perform other tasks. therefore,
Improves overall system performance.

For example, in the system of this embodiment in which the storage capacity of the input line buffer 10G is set equal to the number of dots in the longitudinal direction of an A3-sized original as described above, when the A4-sized original is main scanned in its lateral direction, the latter Image data for two lines of a document can be transferred as a unit to the compression/reproducing section 32.

Therefore, the number of lines of image data processed by the CPU 10 is virtually halved compared to the conventional method, and the frequency with which the system program starts the flow shown in FIG. The number of will decrease. In other words, the time that cpo io is involved in the compression/reproduction unit 32 is reduced, and the performance of the entire system is improved.

Also, as a side effect, if the processing speed of cpttto is sufficiently high compared to the data transfer time, the overall time required to finish processing one page of image data will be shortened. Sometimes.

According to the present invention, image information is compressed and reproduced in such a way that the storage capacity of the line buffer of the single-image information compression and reproduction section is effectively used, and if there is a reproduction error, it is corrected. The data from the previous line is used instead. therefore,
There is less disturbance in the reproduced image, and moreover, a larger amount of image information can be processed at high speed. Furthermore, processing time for other slave units in the system is freed up, and the performance of the entire system is improved. In addition, this method
This can be realized without modifying the configuration of the compression/reproduction unit or the like.

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram showing the configuration of an embodiment in which the image information reproduction error processing device according to the present invention is applied to a data processing system that can also handle image data as one of various data. FIG. 3 is a block diagram illustrating the configuration of the compression/reproduction section shown in relatively detail; FIG. 3 is a flowchart showing the operation flow of the compression/reproduction processing section program executed by the CPU shown in FIG. 4 is an explanatory diagram for explaining the basic principle of compression encoding and reproduction method of image information in the embodiment shown in FIG. 2, and FIG. 5 to FIG. These are explanatory diagrams used to explain the operation of the example. FIG. 5 shows an example of an original image, FIG. 6 shows an example of a reproduced image obtained by reproducing the original image by the method of the present invention, and FIGS. 7 and 8 show an example of an original image. Other comparative examples are shown below. Explanation of symbols for parts 10, CPU 32, Compression/reproduction section 31, Image information memory 10Q, Input line buffer γ 102, Compression/reproduction processing section 104, Output line buffer toe,... Unit control section

Claims (1)

[Scope of Claims] One-dimensional compression-encoded image data is encoded and reproduced in units of data of a plurality of successive predetermined main scanning lines included in image data formed by raster scanning of an original image,
An image information reproduction error processing device for processing errors in code reproduction, the device comprising: storage means for storing the compressed and encoded image data; and code reproduction of the image data stored in the storage means. and code reproducing processing means, when there is a reproducing error in code reproducing the image data stored in the storage means, the code reproducing processing means is configured to reproduce data of the plurality of predetermined main scanning lines containing the error. An image information reproduction error processing device characterized in that the data of one main scanning line immediately before that is replaced instead.