JPH05110829A - Picture data processor - Google Patents

Abstract

PURPOSE:To improve the data processing speed of the picture data processing unit having a decoding function and a reduction function of picture data. CONSTITUTION:A decoding circuit 12 receives compressed picture data from a memory 11 under the control of a control circuit 15 to decode the picture data before compression. The decoded picture data are written in a line buffer 13 and given to a reduction circuit 14 simultaneously. Upon the receipt of the picture data from the decoding circuit 12, the reduction circuit 14 executes logic arithmetic operation to reduce the picture at a prescribed reduction rate. A memory control circuit 15 checks a bit number of the picture data outputted from the reduction circuit 14 and writes the result to the memory 11 every time the bit number reaches a prescribed bit number. In the picture data processor, after the decoding processing, the picture data are directly given to the reduction circuit 14 without being stored in the memory 11 and the reduction processing is executed, then the processing time is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image data processing apparatus for decompressing compressed image data, performing reduction processing and displaying the compressed image data.

[0002]

2. Description of the Related Art Generally, when displaying a high-resolution image on a CRT display or the like, it is common to thin out image data.
Although image reduction processing is performed, since the image data is usually compressed in data and stored in the memory, it is necessary to restore the image data before compression before the reduction processing.
An example of a conventional image processing apparatus that performs such processing is shown in FIG.
Shown in. The data-compressed high-resolution image data is stored in the memory 31, and the decompression circuit 32 uses the memory 31.
The image data is read from the image data, and predetermined processing is performed to restore the image data before compression. The restoration circuit 32 writes the restored image data in the memory 31. The reduction circuit 33 reads the restored image data from the memory 31 and performs a predetermined reduction process. The data after the reduction processing is written in the memory 31. The image data written in the memory 31 is then transferred to the video RAM and displayed by a display device such as a CRT display.

[0003]

In such a conventional image processing apparatus, the original image data is restored from the compressed image data, the image data is once stored in the memory, and then the image data is again stored in the memory. Since the image data is read and the reduction processing is executed, there is a problem that it takes a long time from the start of restoration to the completion of image display.

The present invention has been made in view of the above problems, and an object thereof is to display an image from the start of restoration in an image data processing apparatus for restoring compressed image data, performing reduction processing, and displaying. To reduce the time required to complete.

[0005]

In order to achieve the above-mentioned object, an image data processing apparatus of the present invention stores a compressed image data and a compressed image data read from the storage unit. Restoring means for restoring the image data to the image data, reduction processing means for performing reduction processing on the restored image data output from the restoring means, and writing the same in the storage means,
And a means for transferring the reduced image data from the storage means to the outside.

[0006]

The restoring means restores the original high resolution image data from the compressed data read from the storing means. The restored data is directly passed to the reduction processing means, and reduction processing such as thinning is executed. The data subjected to the reduction processing is written in the storage means. The written data is video RA
It is transferred to M etc. and the image is displayed.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows a block diagram of an image processing apparatus according to the present invention. In the figure, the memory 11 stores high-resolution image data that has been data-compressed. The decompression circuit 12 performs decompression processing on the compressed data read from the memory 11 to decompress the image data before compression. The line buffer 13 stores one line of the image data restored by the restoration circuit 12. The data for one line can be recorded in MR (modified READ) system or MMR (modified modified).
It is used as reference line data when decompressing image data compressed by the READ method. Reduction circuit 1
Reference numeral 4 executes a predetermined logical operation on the restored image data output from the restoration circuit 12 in order to reduce the high resolution image, and writes the processing result in the memory 11. The memory control circuit 15 reads the image data from the memory 11 to the restoration circuit 12, writes / reads the image data output from the restoration circuit 12 to the line buffer 13, and writes the image data output from the reduction circuit 14 to the memory 11. Control writing and so on.

Next, the operation of the image data processing apparatus will be described with reference to the flowchart of FIG. First, prior to the execution of the reduction processing, parameters (reduction ratio etc.) necessary for the processing are set in each circuit (step S21). The decompression circuit 12 outputs a control signal and an address signal for accessing the memory 11 to the memory control circuit 15 to request compressed image data (step S22). When the memory control circuit 15 receives this request, it supplies the address signal from the restoration circuit 12 to the memory 11, and causes the restoration circuit 12 to output the image data of the address designated by the signal (step S23).

The decompression circuit 12 decompresses the original image data before compression from the compressed image data output from the memory 11, and writes it in the line buffer 13 under the control of the control circuit 15 and at the same time the reduction circuit 14 Pass to. The reduction circuit 14 performs a logical operation process on the restored image data received from the restoration circuit 12 to reduce the high resolution image by a predetermined magnification (step S24). At this time, the memory control circuit 15 checks the number of bits of the image data output from the reduction circuit 14 (step S25). If the number of bits reaches the predetermined number, the memory control circuit 15 writes this in the memory 11, and otherwise, to step S27. move on.

In step S27, it is checked whether or not the restoration processing of the compressed image data for one line is completed. "NO"
In the case of, the processing of steps S24 to S27 is repeated. When the restoration process and the reduction process for one line are completed, it is checked whether or not the process for one page of the image is completed (step S28). If "NO", step S2
Returning to step 2, steps S22 to S28 are repeated until the processing for one page is completed.

[0011]

In the image data processing device of the present invention, the restored image data output from the restoring means is
The data is directly passed to the reduction processing means, subjected to the reduction processing, and then written in the memory. Therefore, there is an effect that the time required from the start of restoration to the completion of image display is shortened.

[Brief description of drawings]

FIG. 1 is a block diagram of an image processing apparatus according to the present invention.

FIG. 2 is a flowchart for explaining the operation of the image processing apparatus in FIG.

FIG. 3 is a block diagram of a conventional image processing apparatus.

[Explanation of symbols]

 11, 31 memory 12, 32 restoration circuit 13 line buffer 14, 33 logical operation reduction circuit 15 memory control circuit

Claims (1)

[Claims] 1. An image data processing device having an image data restoring function and a reducing function, comprising: storing means for storing compressed image data; and original data obtained by reading the compressed image data from the storing means. Restoration means for restoring the image data, reduction processing means for performing reduction processing on the restored image data output from the restoration means and writing the same in the storage means, and the reduced image data for the storage means And a means for transferring the image data to the outside.