JPH0537793A - Picture data storage read system and picture data conversion system - Google Patents

Abstract

PURPOSE:To increase the data quantity stored in a video RAM area by decreasing the capacity of a video RAM. CONSTITUTION:A picture data is subjected to compression conversion into a converted data by a converter and stored in a video RAM. Moreover, the data stored in the video RAM is restored to a substantial picture data by a converter 2 and outputted to a display device such as a CRT.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to image data processing, and more particularly to a method for compressing and storing or reading image data and a method for converting image data.

[0002]

2. Description of the Related Art Conventionally, a method of storing or reading image data of this type is to store the image data as it is in a video random access memory (hereinafter referred to as a video RAM) and to store the image data as it is in the video RAM. It is reading.

[0003]

As described above, in the conventional image storage system, the image data is stored in the video RAM as it is. Therefore, a large capacity video RAM is required, and the video RAM area can be effectively used. The drawback is that it is not done.

The object of the present invention is to solve the above-mentioned drawbacks by reducing the amount of information by converting image data into compressed data and reducing the amount of video RAM, thereby reducing the amount of video R.
An object is to provide an image data storage / readout method and an image data conversion method capable of increasing the amount of data stored in the AM area.

[0005]

According to a first aspect of the present invention, there is provided an image data storage / readout system in which a large amount of image data is compressed and converted, and the compressed image data is stored in a video random access memory. The compressed image data is read from and is subjected to the inverse conversion that is the reverse of the compression conversion to restore the image data.

In the image data conversion method of the second invention, a series in which the same numbers of image data are continuous is divided into one group, and the numbers constituting each divided group are converted into 1b of the converted data.
It is output as the it-th eye, and the number obtained by subtracting 1 from the number present in each group of the numbers forming each group is output as the 2-5-th bit, and each group is converted into the conversion data composed of 5 bits.

According to the image data conversion method of the third invention, in the image data conversion method of the second invention, the image data in which 17 or more same numbers continue is made up of a maximum of 16 numeral strings as one group. It is divided.

[0008]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a diagram for explaining a storing / reading process of an image data storing / reading system according to an embodiment of the present invention.

In FIG. 1, image data is compressed and converted into conversion data by conversion 1 and stored in a video RAM. Further, the data stored in the video RAM is converted back to the original image data by the conversion 2 and output to a display device such as a CRT.

FIG. 2 is a flow chart of the data conversion process of the image data conversion system according to the embodiment of the present invention.

In FIG. 2, the image data conversion method of this embodiment shows the conversion 1 of FIG.

First, in step 11, the image data is divided into groups. That is, regarding image data, a series in which the same numbers are consecutive is defined as one group. However, if 17 or more consecutive numbers are the same, a maximum of 16 number strings are divided into one group.

Next, in step 12, each group is converted into converted data and output. That is, the conversion data consisting of 5 bits for each group divided in step 11 is output by the following method.

(1) The numbers constituting each group are output as the first bit.

(2) The number obtained by subtracting 1 from the number existing in each group of the numbers is output as the 2nd to 5th bits.

Then, in step 13, the data conversion is continued. That is, step 12 is repeated until the data conversion is completed.

FIG. 3 is a diagram showing an example of data conversion processing by the image data conversion method of this embodiment.

As shown in FIG. 3, the conversion process (algorithm) of this embodiment shows the conversion 1 of FIG. 1, and the image data is converted into the conversion data by this conversion process.

The conversion 2 is the reverse of the conversion 1.

[0021]

As described above, according to the image data storing / reading method and the image data converting method of the present invention, the capacity of the video RAM is reduced by converting the image data into compressed data and reducing the information amount. Let video RA
There is an effect that the amount of data stored in the M area can be increased.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a storing / reading process of an image data storing / reading method according to an embodiment of the present invention.

FIG. 2 is a flowchart of a data conversion process of an image data conversion method according to an embodiment of the present invention.

FIG. 3 is a diagram showing an example of data conversion processing by the image data conversion method of the present embodiment.

Claims (3)

[Claims] 1. A large amount of image data is compressed and converted, the compressed image data is stored in a video random access memory, the compressed image data is read from the video random access memory, and the compression conversion is reversed. An image data storing / reading method characterized in that the image data is restored by performing an inverse conversion of the above. 2. A number which constitutes each group by dividing a series in which the same number of image data is continuous into one group and outputting the number constituting each group thus divided as the first bit of the conversion data. The number obtained by subtracting 1 from the number existing in each of the groups is output as the 2nd to 5th bits, and each group is output as 5bi.
An image data conversion method, characterized in that conversion is made into conversion data consisting of t. 3. The image data conversion method according to claim 2, wherein the image data in which 17 or more same numbers continue is
An image data conversion method characterized by dividing a maximum of 16 numeral strings into one group.