JPH06225123A - High speed restoring method for picture data - Google Patents

Abstract

PURPOSE:To reduce a data expansion processing time and to attain high speed search by using a decoding means so as to restore picture data of a specific line from picture data compressed, stored and coded in a storage means. CONSTITUTION:Picture data compressed and stored in a RAM 8 consist of an EOL code obtained by coding a consecutive length of same color picture elements of white and black picture elements appearing alternately on the entire scanning lines and of a linear data code. When a CPU 1 reads the compressed data from the RAM 8 and finds out the EOL code, the CPU 1 checks whether or not a line count for linear data restoration is an integral multiple of the reduction rate. When the count is an integral multiple, a final bit address of the EOL code is given to a data compression expansion section 7, which is started. The circuit section 7 starts expansion by the given parameter and restores the compressed data into the picture data and write the data to a picture data area of the RAM 8. Thus, the data expansion processing time is reduced to attain high speed search by decoding only the picture data of a specific line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic file, a personal computer, which stores compressed data, restores the read compressed data, and displays the restored image data.
Furthermore, the present invention relates to a high-speed restoration method of image data used in a visual facsimile apparatus.

[0002]

2. Description of the Related Art A conventional high-speed electronic file search will be described as an example.

When search conditions are input from a keyboard or the like and search execution is instructed, the index information stored in the storage device is read, the CPU searches for materials that meet the input search conditions, and the corresponding materials are displayed on the display. Display the index of. Next, when the high speed search is instructed, the processing is sequentially repeated in the following processing procedure for the material corresponding to the previous search until the search stop is instructed. (See FIG. 9) The display control circuit sequentially reads the data in the VRAM at a predetermined timing, repeats sending the data to the display, and the expanded image data is sequentially displayed on the display.

Step S1: The compressed data of the image corresponding to the index is read from the storage device into the compressed data reading area of the RAM.

Step S2: The decompression circuit unit of the data compression / decompression circuit is activated, the read compressed data is read, decompressed into image data, and the decompressed image data is written into the image data area of the RAM.

Step S3: The image editing unit is activated, and the expanded image data is reduced to a predetermined magnification and written in a predetermined area of the VRAM.

[0007]

However, in the conventional image data apparatus, the resolution read by the scanner or the like in the high-speed search is often higher than the resolution of the display apparatus, and since the entire original is displayed, the expanded image is displayed. It is displayed in a reduced size. Therefore, all the compressed data of the original image read from the storage device is decompressed and then reduced to a predetermined magnification for the search, which takes time to process.

There is also a method of storing compressed data of a high-speed search image obtained by reducing the original image in a storage device separately from the compressed data of the original image in order to speed up the high-speed search. The amount of data (compressed data of the original image + compressed data of the high-speed search image) has increased, and the number of documents that can be stored in the storage device has decreased. Further, when the separate data is provided for high-speed search, this data needs to be generated at the time of registration, and the time required for registration is long.

The present invention has been made in consideration of such a situation. Since a part of the compressed data of the original image read from the storage device is restored, the data decompression processing time can be shortened and high speed search can be performed. Provide a restoration method that enables speedup.

Further, since it is not necessary to store separate data for high-speed search, the high-speed search can be speeded up without reducing the number of documents that can be stored in the storage device.

Further, it is not necessary to generate high-speed search data at the time of registration, and the time required for registration can be shortened.

[0012]

According to the invention described in claim 1, storage means for storing compressed data, decompression means for decompressing the compressed data read from the storage means, and decompressed image data are displayed. In the image data device having the display means, the compressed and stored image data is a signal obtained by encoding a continuous length of the same color pixels of white pixels and black pixels which appear alternately on each line of all scanning lines. ,
When the encoded signal is restored to perform reduced display,
A high-speed restoration method of image data, characterized in that the restoration means restores only image data of a specific line.

Further, according to the invention described in claim 2, a storage means for storing the compressed data, a restoring means for restoring the compressed data read from the storage means, and a display for displaying the restored image data are provided. In the image data device, the compressed and stored image data encodes a continuous length of white pixels and black pixels of the same color that appear alternately on the first line of the plurality of scanning lines, and further, other than that. Is a signal obtained by encoding the position of each change pixel on the current encoded scan line with reference to the corresponding reference pixel on the encoded line or the reference line immediately before the encoded line. The image data is characterized by comprising a method of restoring only the image data of a specific line by the restoring means when the coded signal is restored to perform reduced display. It is a high-speed method of recovering.

Further, according to the invention described in claim 3, a storage means for storing the compressed data, a restoring means for restoring the compressed data read from the storage means, and a display means for displaying the restored image data are provided. In the image data device, the compressed and stored image data is a signal obtained by encoding a continuous length of white and black pixels of the same color, which appear alternately on the first line of the plurality of scanning lines,
Further, other continuous scanning lines are coded by referring to the position of each change pixel on the currently coded scanning line and the corresponding reference pixel on the coding line or the reference line immediately before the coding line. In the case where the coded signal is restored and the reduced display is performed, if the parameter value is different from the reduced value of the image, the data of the line at the optimum position is alternately displayed on the neighboring line. An image characterized by comprising a method for restoring only the image data of a specific line by the restoring means, using a signal obtained by encoding the continuous length of the same-color pixels of white pixels and black pixels appearing in This is a high-speed data restoration method.

[0015]

According to the present invention, in an image data device that stores compressed data, restores the read compressed data, and displays the restored image data, a part of the compressed data of the original image read from the storage device. In order to restore the image data, the compressed and stored image data is a signal obtained by encoding a continuous length of the same color pixels of white pixels and black pixels which appear alternately on each line of all scanning lines, and is encoded. When the signal is restored and the reduced display is performed, only the image data of the specific line is restored by the restoring means.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to an embodiment shown in the drawings by taking an electronic file as an example. The present invention is not limited to this.

FIG. 1 shows the basic structure of an electronic file. The electronic file includes a CPU 1, a scanner 2, a display 3, a display controller 4, a VRAM 5, an image editing unit 6, a data compression / decompression unit 7, a RAM 8, a storage device 9, a keyboard 10, and a printer 11.

The CPU 1 controls the whole operation. The scanner 2 is a device that reads a document placed on a document table.
The display 3 displays the image data of the document. The display controller 4 controls the display of the display 3. The VRAM 5 is a storage device that stores display image data. The image editing unit 6 enlarges or reduces the image data,
Move and copy to draw a figure. The data compression / decompression unit 7 restores the compressed image data to the original image data. The RAM 8 temporarily stores various data. The storage device 9 stores registered data, that is, index information, compressed data, and the like. Keyboard 1
0 inputs the instruction information from the key. The printer 11 outputs image data.

Here, the following encoding method is mainly used as a method for compressing and expanding image data in an electronic file / facsimile.

MH encoding system This system is one-dimensional encoding for all scanning lines. The one-dimensional encoding is a method of encoding a continuous length (run length) of white and black pixels of the same color that appear alternately on one line. As shown in FIG. 3, the data format encoded by this method is such that each line has an EOL (End
of line code and data code (one-dimensional), and the RTC (Return) is added at the end of the data code for one page.
to Control) code is added. Six consecutive EOL codes are used as RTC codes.

MR Coding Method In this method, all scanning lines are coded every K lines as follows. After the first scan line is one-dimensionally encoded, a maximum of K-1 consecutive scan lines is two-dimensionally encoded. The two-dimensional encoding refers to the position of each change pixel on the scan line (encoding line) currently encoded, by referring to the corresponding reference pixel on the encoding line or the reference line immediately before the encoding line, This is a coding method. The data format encoded by this method is shown in FIG.
Each line consists of an EOL code + tag bits and a data code. The data code of the first line for each K line is one-dimensionally encoded data, and the remaining data code of K-1 line is two-dimensionally encoded. The data. Further, as the tag bit added before the data code, "1" is used when the data code is one-dimensional coding, and "0" is used when the data code is two-dimensional coding. An RTC (Return to Control) code is added to the end of the data code for one page. Six consecutive EOL codes + 1 are used as the RTC code.

MMR coding method This method is two-dimensionally coded for all scanning lines. When encoding the first line, a hypothetical all-white line is assumed immediately before the encoded line as a reference line. As shown in FIG. 5, the data format coded by this method is such that, as in the MH coding method or the MR coding method, EOL or EOL + tag bits are not inserted before each data code, and the data codes are continuous. RTC (Return to Control) is added at the end of the data code for one page.
l)) A code is added. Two consecutive EOL codes are used as the RTC code.

According to the present invention, the registered image data is
Among the above data compression methods, MH coding method and MR
This is effective when the data is compressed by the encoding method. Here, the processing procedure of steps S2 and S3 of FIG. 9 different from the conventional technique will be described.

Here, the K parameter is M for every line.
It is a numerical value indicating whether to insert H (one-dimensional) compressed data. For example, if the K parameter is 5, the first line is MH (one-dimensional) compressed data, and the lines 2 to 5 have MR (two-dimensional) compressed data.

The present invention is intended to restore only one-dimensional compressed data, and "reduction rate is not an integer multiple of K parameter" means that the line data to be restored is two-dimensional data. Therefore, the process is changed when "the reduction ratio is an integer multiple of the K parameter or not" because it cannot be restored.

Here, the line counter is indicated by n, i is a bit address, l is the number following "0", and A is the address of the compressed data. These n, i, l and A are set in each register provided in the CPU 1.

(1) When the compressed data is data compressed by the MH coding method (see FIG. 5): As the processing of step S2 of FIG. 9: a. The line counter value n is set to 0. Parameters (start address of image data, data pitch of image data in the main scanning direction, etc.) are set in the data expansion circuit.

B. The CPU sequentially reads the read compressed data from the RAM and searches for the EOL code.

C. When the EOL code is found, the line counter value is reduced by m (the ratio of the resolution of the original image and the resolution of the high-speed search image, eg, the reduction rate m is 4 when the resolution of the original image is 400 DPI and the resolution of the high-speed search image is 100 DPI). Check if it is an integer multiple of.

In the case of an integral multiple of the reduction ratio, the data compression / decompression circuit is given the last bit address of this EOL code + 1 as the start address of the compressed data to activate the decompression circuit section. The data compression / decompression circuit section starts decompression with the given parameters, restores the image data, and writes the restored image data in the image data area of the RAM. When the data compression / decompression circuit processes one line of data code, it sets a processing end status and stops the processing. On the other hand, if the line counter value is not an integral multiple of the reduction ratio, the process proceeds to the next processing step d without performing the expansion process.

D. Increment the line counter value.

E. It is checked whether the line counter value is the final line value N.

When n = N is not satisfied, the procedure returns to the processing procedure b, and n
= N, the decompression process ends.

As the processing of step S3 in FIG. 9, the reduction circuit is activated and the restored image data is reduced to 1 / m only in the main scanning direction and written in a predetermined area of the VRAM of the display control circuit.

(2) When the Compressed Data is the Data Compressed by the MR Coding Method When the present invention is used, it is desirable that the value of the K parameter at the time of compression be an integer which is a fraction of the reduction ratio m. If not, distortion occurs in the reduced image, but in the case of high-speed search, some distortion does not pose a problem, so the method described below may be used.

(A) The reduction ratio is an integer multiple of the K parameter (see FIG. 6). As the processing of step S2 in FIG. 9, a. The line counter value n is set to 0. Parameters (start address of image data, data pitch of image data in the main scanning direction, etc.) are set in the data expansion circuit.

B. The CPU sequentially reads the compressed data read from the RAM and searches for the EOL code.

C. When the EOL code is found, it is checked whether the line counter value is an integral multiple of the reduction rate m.

In the case of an integral multiple of the reduction ratio, the data compression / decompression circuit is given the last bit address of this EOL code + 2 as the start address of the compressed data to activate the decompression circuit section. The data compression / decompression circuit section starts decompression with the given parameters, restores the image data, and writes the restored image data in the image data area of the RAM. Data compression
When the decompression circuit processes the data code for one line, it sets a processing end status and stops the processing. On the other hand, if the line counter value is not an integral multiple of the reduction ratio, the process proceeds to the next processing step d without performing the expansion process.

D. Increment the line counter value.

E. It is checked whether the line counter value is the final line value N.

When n = N is not satisfied, the procedure returns to the processing procedure b, and n
= N, the decompression process ends.

As the processing of step S3 in FIG. 9, the reduction circuit is activated to reduce the restored image data to 1 / m in the main scanning direction, and V of the display control circuit is used.
Write to a predetermined area of RAM.

(B) When the reduction ratio is not an integer multiple of the K parameter and the reduction ratio is larger than K (see FIG. 7): As the processing of step S2 in FIG. The line counter value n, register i, register 1 and register j are set to 0. Parameters (start address of image data, data pitch of image data in the main scanning direction, etc.) are set in the data expansion circuit.

B. The CPU sequentially reads the compressed data read from the RAM and searches for the EOL code.

C. When the EOL code is found, the next bit of the EOL code is checked. If 1, go to step d,
If 0, go to step g.

D. It is checked whether the line counter value is equal to or larger than j times m. If the line counter value is equal to or larger than m times K, or greater, the data compression / decompression circuit is given the last bit address +2 of the EOL code as the start address of the compressed data to activate the decompression circuit section. The data compression / decompression circuit section starts decompression with the given parameters, restores image data, and R
The restored image data is written in the image data area of AM. When the data compression / decompression circuit processes one line of data code, it sets a processing end status and stops the processing. On the other hand, if the line counter value is smaller than m times K, the process proceeds to step f without performing the expansion process.

E. Increment j.

F. Add K to the line counter value.

G. It is checked whether the line counter value is the final line value N.

When n = N is not satisfied, the procedure returns to the processing procedure b, and n
= N, the decompression process ends.

As the processing of step S3 in FIG. 9, the reduction circuit is activated and restored, but the data is set to 1 in the main scanning direction.
/ M, VRA of display control circuit
It is written in a predetermined area of M.

(C) When the reduction ratio is not an integral multiple of the K parameter and the reduction ratio is smaller than K (see FIG. 8): As the process of step S2 in FIG. The line counter values n and m are set to 0. Parameters to the data decompression circuit (start address of image data,
The data pitch of the image data in the main scanning direction, etc.) is set.

B. The CPU sequentially reads the compressed data read from the RAM and searches for the EOL code.

C. When the EOL code is found, the next bit of the EOL code is checked. If 1, go to step d,
If it is 0, proceed to step f.

D. The data compression / decompression circuit is given the last bit address of this EOL code + 2 as the start address of the compressed data to activate the decompression circuit section. Data compression
The decompression circuit unit starts decompression with given parameters, restores the image data, and writes the restored image data in the image data area of the RAM. When the data compression / expansion circuit processes the data code for one line, it sets the processing end status and stops the processing.

E. Add K to the line counter value.

F. It is checked whether the line counter value is the final line value N.

When n = N is not satisfied, the procedure returns to the processing procedure b, and n
= N, the decompression process ends.

As the processing of step S3 in FIG. 9, the reduction circuit is activated and the restored image data is reduced to 1 / m in the main scanning direction and enlarged to K / m in the sub-scanning direction, and the display control is performed. It is written in a predetermined area of the VRAM of the circuit.

[0061]

According to the present invention, since a part of the compressed data of the original image read from the storage device is restored, the data decompression processing time can be shortened and the high speed search can be speeded up. Further, since it is not necessary to store separate data for high-speed search, the high-speed search can be speeded up without reducing the number of documents that can be stored in the storage device.

Furthermore, it is not necessary to generate high-speed search data at the time of registration, and the time required for registration can be shortened.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of an electronic file to which the present invention is applied.

FIG. 2 is a diagram illustrating a format of compressed data that generally uses an MH encoding method.

FIG. 3 is a diagram illustrating a format of compressed data that generally uses an MR encoding method.

FIG. 4 is a diagram showing a format of compressed data generally using an MMR encoding method.

FIG. 5 is a flowchart showing an operation according to the method of the embodiment of the present invention when the compressed data is data compressed by the MH encoding method.

FIG. 6 is a case where the compressed data is data compressed by the MR encoding method and the reduction rate is an integer multiple of the K parameter,
6 is a flowchart showing an operation according to the method of the embodiment of the present invention.

FIG. 7 is a diagram illustrating a method according to an embodiment of the present invention when the compressed data is data compressed by the MR encoding method and the reduction ratio is not an integral multiple of the K parameter and the reduction ratio is larger than the K parameter. It is a flow chart which shows operation.

FIG. 8 is a diagram illustrating a method according to an embodiment of the present invention when the compression data is data compressed by the MR encoding method and the reduction ratio is not an integral multiple of the K parameter and the reduction ratio is smaller than the K parameter. It is a flow chart which shows operation.

FIG. 9 is a flowchart showing a conventional high-speed search process.

[Explanation of symbols]

 1 CPU 2 Scanner 3 Display 4 Display Controller 5 VRAM 6 Image Editing Section 7 Data Compression / Expansion Section 8 RAM 9 Storage Device 10 Keyboard 11 Printer

Claims (3)

[Claims] 1. An image data device having a storage unit for storing compressed data, a restoring unit for restoring the compressed data read from the storage unit, and a display unit for displaying the restored image data, which is compressed and stored. The image data is a signal obtained by encoding a continuous length of white pixels and black pixels of the same color that appear alternately on each line of all scanning lines, and performs reduced display by restoring the encoded signal. In this case, a high-speed restoration method of image data, characterized in that the restoration means restores only the image data of a specific line. 2. An image data apparatus having storage means for storing compressed data, decompression means for decompressing the compressed data read from the storage means, and display means for displaying the decompressed image data, which are compressed and stored. The image data is encoded by encoding the continuous length of white and black pixels of the same color that appear alternately on the first line of the plurality of scan lines, and further encoding the other continuous scan lines at present. The position of each change pixel on the scanning line is a signal encoded by referring to the corresponding reference pixel on the encoding line or the reference line immediately before the encoding line, and the encoded signal is restored. A high-speed restoration method of image data, characterized by comprising a method of restoring only the image data of a specific line by the restoration means when performing reduced display. 3. An image data device having a storage means for storing compressed data, a restoring means for restoring the compressed data read from the storage means, and a display means for displaying the restored image data, which is compressed and stored. The image data is a signal obtained by encoding a continuous length of white pixels and black pixels of the same color that appear alternately on the first line of the plurality of scanning lines, and
A signal obtained by encoding the position of each change pixel on the currently encoded scan line for other continuous scan lines by referring to the corresponding reference pixel on the encode line or the reference line immediately before the encode line. In the case where the encoded signal is restored to perform reduced display, when the parameter value is different from the reduced value of the image, the data of the line at the optimum position appears alternately on the neighboring lines. The image data is characterized by comprising a method of restoring only the image data of a specific line by the restoring means, using a signal obtained by encoding a continuous length of the same color pixels of white pixels and black pixels as an approximate value. Fast restore method.