JPS62154152A - Virtual memory management method for picture - Google Patents

Abstract

PURPOSE:To eliminate the disuse of pictures which are under processing even though a memory has no space and at the same time to secure parallel processing with high efficiency, by connecting a picture compressing/expanding circuit and a secondary storage medium to a picture memory. CONSTITUTION:A request is first received for development of pictures onto an image memory and an image memory 33 has no space. Under such conditions, a CPU 32 compresses pictures which are not under processing to transfer to and store them in a secondary storage medium 35. Then the image memory of the corresponding picture is erased. Thus the CPU 32 produces a new picture memory on the memory 33 for requested pictures. Then the compressed pictures are read out of the medium 33 and expanded to be developed to the memory 33.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a virtual memory management method for images in a so-called virtual memory system, which makes it possible to virtually use a large amount of image memory that is not used for image processing.

2. Description of the Related Art In the conventional image virtual memory management method of this type, as shown in FIG. 3, when there is a request to develop an image onto an image memory provided separately from the main memory (step: 5T1)
The CPU (Central Processing Unit) judges whether there is free space in the image memory (5T2), and if there is free space (5T2).
(YES in ST2), creates a new image memory (image memory) on the image memory to expand the requested image (ST5), and loads the image onto the image memory. Processing is done to expand (S
T6), and if there is no free space (S T2), a message is sent to the CPU to abandon part of the image currently being processed and erase the memory for that image (
Based on a request from Sr1) or another request (Sr4), in order to secure a new image memory area, CI)U erases part of the image memory that is currently being processed. , then create a new image memory 5
T5), and fST6), in which the requested image is being expanded into the image memory.

As shown in FIG. 4, the hardware configuration required to implement the conventional method described above includes a main memory 2 that can be directly accessed by the 0PUI, and an image provided separately from the main memory 2 via a system bus 3. - A memory 4, a display device 6 that displays the image A developed on the image memory 4 via the image memory display section 5, and an input section (keyboard, mouse, etc.) for inputting image processing commands. )7.

The main memory 2 includes an image processing means 21 for processing an image based on command input from the input section 7;
An image memory processing section 22 that develops an image into an image memory on the memory 4, an image memory creation section 23 that creates an image memory on the image memory 4, and an image memory creation section 23 that erases images that should be discarded. It consists of an image memory deletion section 24 for deleting image memory and securing a new image memory area.

Problems to be Solved by the Invention However, with this configuration, the number of images that can be processed is determined by the capacity of the main memory. There was a problem in that image memory for storing the image could not be secured unless a part of the image was discarded. In particular, there was a serious problem in that parallel processing of images could not be performed when the program was multitasking.

The above-mentioned problem occurs due to the finite capacity of the main memory.

Therefore, as a countermeasure, increase the main memory capacity.
Although this is possible, it increases memory cost and is not practical. In addition, the virtual memory management program
Although it is possible to manage the image data area while temporarily saving it on a secondary storage medium (such as a floppy disk), the capacity of the image data is, for example, 8 dots/mm on A4 size paper.
It is as large as 512 Kbytes, and the storage efficiency is poor.
Furthermore, there is also a problem with the transfer speed to the secondary storage medium.
Unfortunately, it's not practical.

The present invention has been made in view of the above-mentioned circumstances, and is an image processing system with high usage efficiency that allows processing of a plurality of different images in parallel without abandoning the image currently being processed as in the past. The purpose is to provide a virtual memory management method.

In order to solve the above-mentioned problems, the present invention provides a circuit for compressing and decompressing images and a secondary storage medium connected to the main memory, thereby saving images that do not currently need to be processed. is transferred to the secondary storage medium in a compressed form for storage and processing: Only the image of 1 is expanded onto the image memory, and the requested image is stored and stored as a compressed image in the secondary storage medium. If the compressed image is stored, the compressed image is extracted and decompressed, and then expanded on the image memory.

Operation With the above configuration, the image to be processed can be stored as much as the capacity of the secondary storage medium, and since the image is stored in a compressed form, the image memory is used efficiently, and the image can be stored in the secondary storage medium. The access speed will also be faster. This is from K.
Even in multitasking programs, each program can efficiently process multiple different images in parallel.

Embodiment FIG. 1 is a flowchart showing an embodiment of the processing operation of the image virtual storage management method according to the present invention.
1 to 5T28 indicate steps of each processing operation.

The method of the present invention will be explained based on FIG.

First, when there is a request to develop an image onto the image memory (Sr21), the CPU determines whether or not there is space in the image memory (Sr22).

So, if there is a vacancy (YES at 8T22), immediately,
An image memory (hereinafter referred to as image memory) for developing a newly requested image (hereinafter referred to as requested image) is created in the image memory (ST2
5).

If there is no free space (A in ST22), the image that is currently not being processed is compressed and transferred to a secondary storage medium for storage (ST23). Next, the image memory for that image is erased (ST24). This makes it possible to secure a new image memory creation space (area).

Next, a new image memory for the requested image is set to 8II.
It is created on the image memory (ST25).

When the image memory creation (ST25) is completed in this way, the CPU checks whether the requested image is stored as a compressed image in the secondary storage medium (ST2).
6).

Therefore, when it is determined that the requested image is stored as a compressed image (YES in ST26), the compressed image is read from the secondary storage medium, decompressed, and then expanded and processed in the image memory. (ST27).

If it is determined that the requested image is not stored (No in ST26), the requested image is directly developed and processed in the image memory (ST28).

Next, FIG. 2 shows an example of a schematic configuration of hardware for implementing the above-described method of the present invention.

In FIG. 2, 31 is a main memory that can be directly accessed by the CPU 32, and 33 is an image memory provided separately from the main memory 31. An image memory is created in this image memory 33, and a requested image A is stored in this image memory. is expanded. 34 is an image compression/decompression circuit, 35 is a secondary storage medium, and the image memory 33 is stored in this storage medium 35.
The above compressed image diagram in which the currently unprocessed image is compressed by the compression/expansion circuit 34 shows the compressed image A obtained by compressing the requested image A) is transferred and stored. 36 is an image
An image memory display and processing unit 37 processes the image on the memory 33 to display it, a display device 37 displays the image processed by the processing unit 36, and an input unit 38 inputs image processing commands. 39 is a system bus, 40 is a keyboard or (note: consists of a mouse, etc.)
is an image bus.

The main memory 31 includes an image processing unit 311 that processes images based on command input from the input unit 38, an image memory processing unit 312 that develops and processes a requested image onto the image memory 33, and an image memory. an image memory request unit 313 that requests image memory, a virtual memory management unit 314 that manages virtual memory based on the image memory request, an image memory management unit 315 that manages the image memory 33, and an image memory management unit 315 that manages the image memory 33; an image memory creation unit 316 that creates an image memory in the image memory 33; and an image memory deletion unit that deletes the image memory of images that are currently not being processed in the image memory 33 to secure a new image memory area. 317, a compressed image management unit 318 that manages compressed images in the secondary storage medium 35,
The image compression/decompression section 319 compresses images from the image memory 33 via the decompression circuit 34 or decompresses compressed images from the secondary storage medium 35.

Next, the operation will be explained with reference to FIG.

First, in response to the requested image processing command given from the input unit 38, the image processing means 311 secures a memory for the requested image in the image memory 33, creates the requested image A here, and processes the requested image A. Process and edit the data.

Next, assume that when a different requested image is to be processed, the image memory 33 has already stored images to its full capacity. At this time, the virtual memory management means 314 detects this, compresses the currently unprocessed image A, transfers and stores the compressed image A to the secondary storage medium 35, and at the same time transfers the image memory to the image memory 33. Delete from. As a result, a new image memory area is secured on the image memory 33.

Therefore, the virtual memory management means 314 creates a new image memory on the image memory 33 via the image memory creation unit 316.

The image processing means 311 stores the different requested image in the created new image memory and processes and edits it.

After this processing/editing is completed, the image processing means 311 again requests the -C virtual memory management means 314 via the image memory requesting section 313 for the image previously transferred and stored in the secondary storage medium 35 as the compressed image A. Then, the virtual memory management unit 314 reads the compressed image A from the secondary storage medium 35 via the compressed image management unit 318, and performs image compression/image compression.
Expanded via the expansion unit 319 and compression/expansion circuit 34,
The decompressed image A is expanded again in the image memory created on the image memory 33 in the same manner as described above.

In this way, in the present invention, the image processing means 311 performs image processing on the image memory 33, assuming that there is an apparently infinite amount of image memory, without worrying about the remaining area, addresses, etc. on the image memory 33. Memory can be secured.

As the compression/expansion circuit 34, for example, a compression speed of 1w of A4 size 8 dots/IrIm, which is currently in practical use, can be used.
4 for an average of 035 seconds, and the compression rate is preferably about the average IA, but it is desirable to select and use it as appropriate depending on the image.

Still, the image processing means 311 and the virtual memory management means 314 are each executed by a management program.

Effects of the Invention In short, the present invention provides a circuit for compressing and decompressing images;
A secondary storage medium is provided in conjunction with the main memory, images that are not currently being processed are stored in the secondary storage medium in a compressed form, and only images that are being processed are expanded on the image memory;
Furthermore, when a compressed image is required, it is decompressed and expanded on the image memory, which improves the usage efficiency of the image memory and makes it possible to use the secondary storage medium. The access speed to images is also increased, and a plurality of different images can be processed in parallel without discarding images for processing as in the conventional method.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing an example of the processing operation of the image virtual storage management method according to the present invention, and FIG. 2 is a block diagram showing an example of the schematic configuration of hardware for implementing the method of the present invention. FIG. 3 is a flowchart of processing operations based on the conventional method, and FIG. 1 is a schematic block diagram of the hardware configuration required to implement the conventional method. 31... Main memory, 311... Image processing means, 31
4... Virtual memory management means, 32... CPU (central processing unit), 33... Image memory, 34...
・Compression/expansion circuit, 35... Secondary storage medium, 38...
- Input section, 39... System bus, 40... Image path. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure 2 Figure 3

Claims (1)

[Claims] An image memory that can store and process images, a circuit that compresses and expands the images stored in this image memory, and a secondary storage medium that stores images compressed by this circuit are connected to the main memory. and means are provided in the main memory for storing a plurality of independent images onto the image memory, so that when the image memory becomes full of images, the compression circuitry at that time An unprocessed image is compressed, the compressed image is transferred and stored in the secondary storage medium, and at the same time, a new image memory is created on the image memory, and a newly requested image is stored in this image memory. A virtual memory management method for images, characterized in that an image is expanded, and when a compressed image in the secondary storage medium is required, the compressed image is expanded by an expansion circuit and expanded into an image memory. .