JPH0127465B2 - - Google Patents

Description

[Detailed Description of the Invention] (1) Technical Field of the Invention The present invention relates to a segment input method for compressed image data, and in particular, when data stored as compressed image data in memory is displayed on a display. The present invention relates to a segment input method for compressed image data that makes it possible to cut out an appropriate segment area on a display and write it into a memory.

(2) Prior art and problems For example, when inputting image data that has been binarized by a reader, such as paper information such as a photograph or a paper, into memory, if this is to be retained as the original binarized data, it is necessary to use A4 size paper. So about
Since it is a very large amount of 700KB, it is compressed and stored as compressed data. In this case, the amount of data can be compressed to about 1/8 to 1/10 of the original.

By the way, if you want to cut out what you need from this image data and store it separately, you can display the original data of the image data on the display, indicate the area to be cut out with a cursor, for example, The original data in the range indicated by this cursor was retrieved.

Therefore, it is not possible to display, for example, the entire A4 size original data on the display, so the operator needs to move this display area sequentially by scrolling. The disadvantage is that the operation is complicated.

(3) Object of the invention The object of the invention is to enable the extraction of segments from a memory stored with compressed image data. Another object of the present invention is to display thinned-out data on a display so that it can be displayed on the display without scrolling, etc., and to instruct segment cutting using this thinned-out data and compress it. The objective is to make it possible to extract images from the image data that has been created.

(4) Structure of the Invention In order to achieve the above object, the compressed image data segment input method of the present invention:
A data compression means for converting each scanning line of image data into compressed data, a data storage means for storing the compressed data, and a scanning line for instructing the storage location of the compressed data of each scanning line in the data storage means. a management means; a decompression means for decompressing the compressed data into original data for each scanning line;
A clipping area storage means for storing a clipping area of the expanded original data, a data cutting means for cutting out the expanded original data based on the cutting area stored in the cutting area storage means, and the extracted data. The compressed data is read from the data storage means, decompressed, and then cut out by the cutout means, and only the cut out area is compressed again and stored in the data holding means. It is characterized by being stored.

(5) Embodiment of the Invention Before describing the present invention in detail based on an embodiment, the principle of operation thereof will be briefly explained.

In the present invention, a scanning line management table is created that specifies, for each scanning line, at which address on the memory the compressed data for each scanning line is stored. For example, the storage location of the compressed data in the Y-coordinate range of the cutout area designated by the cursor position on the display is recognized from this scanning line management table. Then, the compressed data in the specified range is sequentially read out, restored to original data, and then extracted in the X coordinate range of the cutout area. By doing so, it is possible to selectively extract data in a necessary area from the memory stored as compressed data.

Next, one embodiment of the present invention will be described based on FIGS. 1 and 2.

FIG. 1 is a configuration diagram of an embodiment of the present invention, and FIG. 2 is an explanatory diagram of scanning lines of image data.

In the figure, 1 is a memory, 2 is a reader, 3 is a compression circuit, 4 is a switching circuit, 5 is a control circuit, 6 is an expansion circuit, 7 is an extraction circuit, 8 is a thinning circuit, 9 is a display control circuit, 10 11 is a display, 12 is a cursor control unit, and 13 is a cutting register.

Memory 1 is for storing image data, and has a compressed image data area 1-0 in which image data compressed for each scanning line is stored.
, a scanning line management table area 1-1 in which a scanning line management table indicating the storage location of compressed data of each scanning line is written, and a cutting area 1-1 in which a range of compressed data specified by means as described below is stored. It has a segment area 1-2.

The reader 2 reads, for example, paper information using a photoelectric element, converts it into a binary signal, and creates image data.

The compression circuit 3 creates compressed image data by compressing original image data transmitted from the reader 2 or a cutout circuit 7, which will be described later, using, for example, the Modified Huffman (MH) method.

The switching circuit 4 selectively stores the compressed image data sent from the compression circuit 3 into the compressed image data area 1-0 or the cut-out segment area 1-2 according to instructions from the control circuit 5.

The control circuit 5 stores data in the memory 1,
It reads data from the memory 1, controls switching of the switching circuit 4, etc., and performs other various controls in general.

The decompression circuit 6 restores the compressed image data to uncompressed original data for each scanning line.

The extraction circuit 7 extracts data within a range designated by the control circuit 5 from the original data for each scanning line transmitted from the expansion circuit 6 and transmits it to the compression circuit 3.

The thinning circuit 8 selects the original data transmitted from the decompression circuit 6, for example, line by line in the vertical direction on the display 11, and selects each bit in the horizontal direction, and sends the selected data to the display control circuit 9. , to thin out and reduce the amount of display information on the display.

The display control circuit 9 performs various controls for displaying display data on the display 11 and reads out the cursor position displayed on the display 11.

The display buffer 10 is a buffer in which display data displayed on the display 11 is temporarily set.

The display 11 is a display surface on which various displays are performed.

The cursor control unit 12 performs various controls for moving the cursor position on the display 11.

The cutting register 13 stores coordinate information (x ₁ ,
y ₁ ; x ₂ , y ₂ ) are the registers to be set.

Next, the operation shown in FIG. 1 will be explained.

First, the reader 2 scans the image to be input to generate image data, which is then sent to the compression circuit 3.
to communicate. The compression circuit 3 compresses this image data to create compressed data, and
As shown in FIG. 2, scanning line end signals EOL-0, EOL-1, . . . are applied to the end of each scanning line and sent to the switching circuit 4. At this time, since the control circuit 5 is informed that image scanning will be performed from the reader 2, the control circuit 5 controls the switching circuit 4 so that the output of the switching circuit 4 is stored in the compressed image data area 1-0. . Furthermore, as shown in FIG. 2, the compression circuit 3 reports this to the control circuit 5 every time it outputs compressed data l-0, l-1, l-2, . . . in units of scanning lines. A scanning line management table is created in area 1-1 indicating in which address part of compressed image data 1-0 these pressure line data l-0, l-1, . . . are stored. In this way, compressed image data is stored in the compressed image data area 1-0, and a scanning line management table is created on the area 1-1. If multiple images are input, of course instruction data will be added to identify them.

If only a specific region of the image currently stored as compressed image data is to be extracted, a display signal indicating the image to be extracted is sent to the control circuit 5.
is transmitted to. As a result, the control circuit 5 sequentially reads out the compressed image data related to the designated image in the order of scanning lines from the area 1-0, and the decompression circuit 5
Send to. At this time, the control circuit 5
Since the decompression circuit 6 sequentially outputs the restored original data to the decimation circuit 8, the decompression circuit 6 sequentially outputs the restored original data to the decimation circuit 8. The thinning circuit 8 thins out the data transmitted from the expansion circuit 6 as described above and sends it to the display control circuit 9. The display control circuit 9 sends this thinned-out data to the display buffer 10, so that the desired image is displayed on the display 11. At this time, as mentioned above, display 1
In the vertical direction on the display 11, data is thinned out every scanning line, and in the horizontal direction, data is also thinned out every 1 bit, so in the end, on the display 11, the data is thinned out by 1/2 x 1/2, or 1/4. Since the image is displayed according to its size, and the entire image is roughly the size of one sheet of paper, there is no need to scroll to display the entire image. Moreover, there is no problem in checking the cut-out portion.

After all the images necessary to indicate the cutout area are displayed on the display 11 in this manner, the cursor is moved by normal means to indicate the cutout area. For example, if the cutout area is a hatched area on the display 11 in FIG. 1, the cursor is first placed at point A. At this time, the coordinates (x ₁ , y ₁ ) of point A are transmitted to the extraction register 13 via the display control circuit 9 . Therefore, when a cutout designation signal is input using a keyboard or the like, the cursor control section 12 first sets the coordinates (x ₁ , y ₁ ) of point A in the cutout register 13.
Next, if you move the cursor to the position of point B, the (x ₂ , y ₂ ) of point B will be transmitted to the extraction register 13 in the same way, so if you input the extraction designation signal again, the coordinates ( x ₂ , y ₂ ) are also set in the extraction register 13. When point A (x ₁ , y ₁ ) and point B (x ₂ , y ₂ ), which indicate the cutting area in the cutting register 13, are set in this way, the cursor control unit 12 instructs the control circuit 5 to specify the cutting area. Report that has been specified.

As a result, the control circuit 5 receives the coordinates (x ₁ , y ₁ ), (x ₂ ,
_y2 ). Then, the addresses where the scanning lines ly ₁ to ly ₂ corresponding to the coordinates y ₁ and y ₂ are stored are obtained from the scanning line management table, and the compressed image of the scanning lines ly ₁ to ly ₂ is obtained. ．． Data is sequentially read from areas 1-0, sent to an expansion circuit 6 to be restored to original data, and sent to an extraction circuit 7.

The control circuit 5 converts the original data in the range on the scanning line corresponding to the coordinates x ₁ to x ₂ out of the original data for each scanning line transmitted from the expansion circuit 6 to the extraction circuit 7 . It is controlled so that it is output to the compression circuit 3 in units. The compression circuit 3 then creates compressed data based on the original data in the range corresponding to the coordinates x ₁ to _{x 2} and sends it to the switching circuit 4 . At this time, the control circuit 5 cuts out the data transmitted from the compression circuit 3 to the switching circuit 4 in the segment area 1-2.
The compressed image data thus created by the compression circuit 3 is then stored in the cut-out segment area of the memory 1. In this way, the compressed image data of the area designated by points A and B on the display 11 can be cut out and stored as compressed image data separately from the compressed image data area 1-0.

In the above explanation, the thinning state in the thinning circuit is 1/1 in both the horizontal and vertical directions on the display.
Although an example of two images has been described, it is of course not limited to this, and the size can be appropriately selected depending on the size of the original image so that the entire image can be displayed on the display.

(6) Effects of the Invention According to the present invention, since the storage location of the scanning lines of compressed image data is managed, it becomes possible to selectively and continuously expand and cut out the compressed image data. Therefore, image data can be extracted quickly and efficiently.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention, and FIG. 2 is an explanatory diagram of scanning lines of image data. In the figure, 1 is a memory, 2 is a reader, 3 is a compression circuit, 4 is a switching circuit, 5 is a control circuit, 6 is an expansion circuit, 7 is an extraction circuit, 8 is a thinning circuit, 9 is a display control circuit, 10 11 is a display buffer, 12 is a cursor control unit, and 13 is a cutting register.

Claims (1)

[Scope of Claims] 1. Data compression means for converting each scanning line of image data into compressed data, data storage means for storing the compressed data, and data storage means for compressed data of each scanning line. a scanning line management means for instructing a storage destination; a decompression means for decompressing compressed data into original data for each scan line; a cutout area storage means for storing a cutout area of the decompressed original data; comprising a data extraction means for cutting out data based on the cutout area stored in the cutout area storage means and a data holding means for compressing and storing the cutout data; reading compressed data from the data storage means; A segment input method for compressed image data, characterized in that after decompressing the image, the segment is cut out by the cutting means, and only the cut out area is compressed again and stored in the data holding means.