JPH09292875A - Image processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a request for processing plural pages from a host computer to be accepted and sequentially to be executed by enabling bit map data of plural pages to be temporarily stored in an internal memory of a rasterizer. SOLUTION: A rasterizer receiving image information expressed by page description language from a host computer 2, expanding it to bit map data, and transferring to the host computer 2, such rasterizer is provided with a memory 16 having its capacity for storing bit map data for plural pages that is a temporary storage area of bit map data and memory management means for managing the storage position of bit map data of each page on a memory 16 based on the data quantity of bit map data of each page.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus which is a rasterizer which receives image information expressed in a page description language from a host computer, develops it into bitmap data and transfers it to the host computer. In particular, it relates to technical improvement for adapting to a system in which processing requests from a host computer frequently occur.

[0002]

As is well known, a rasterizer which is an image processing apparatus is applied not only for the purpose of generating bitmap data for printing on a page printer but also for the following system. ing.

In the facsimile information service system,
When the user's facsimile machine calls the service providing machine to connect the line and specify the desired information number according to the guide information, the specified image information stored in the service providing machine is transmitted to the user's facsimile machine.
Bitmap data of many images to be serviced is stored in the service provider. The bitmap data may be a document image read by an image scanner, but an image that is electronic data generated by computer processing such as word processing, DTP, or CAD without passing through the image printed on the document may also be used. Used. In the latter case, normally, the image of the bitmap data is not directly generated by computer processing, but at the processing stage of word processing, DTP, CAD, etc., the image is expressed in a page description language, and the image is expressed using a rasterizer. It is expanded to map data.

[0004]

In the facsimile information service system as described above, the rasterizer is connected to the host computer (workstation) which is the main body of the service provider by an interface such as SCSI. Image information in page description language format is passed from the host computer to the rasterizer, and a request for bitmap expansion processing is issued. In response to this, the rasterizer executes processing and transfers the generated bitmap data to the host computer.

The conventional rasterizer of this type has a structure for exchanging the bit map expansion work for each page with the host computer. That is,
When a one-page work request is received from the host computer and the one-page bitmap data is passed to the host computer, the next one-page work request can be accepted. Until I finish the work of one page and transfer the bitmap data to the host computer,
I cannot accept the next job. Also, it is not designed to accept requests for work on multiple pages at a time.

Since the host computer is in charge of a huge amount of work as a service providing machine of the facsimile information service system, if the bitmap expansion processing can proceed only on a page-by-page basis as described above due to the relationship with the rasterizer, the whole host computer can be processed. It will be difficult to rationally assemble the work setup. Therefore, there has been a problem that the overhead of the system becomes large.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to enable a host computer to temporarily store a plurality of pages of bitmap data in a memory inside a rasterizer. It is to accept requests for processing of a plurality of pages and sequentially execute the requests.

[0008]

Therefore, the present invention provides a rasterizer which receives image information expressed in a page description language from a host computer, develops it into bitmap data, and transfers it to the host computer. , A memory having a capacity for storing the bitmap data of a plurality of pages, which is a temporary storage area of the bitmap data, and a memory of each page on the memory based on the data amount of the bitmap data of each page. A memory management unit for managing the storage location of the bitmap data is provided.

Further, in the above configuration, preferably, when another processing request is received from the host computer while the bitmap data expansion processing is being executed, the processing being executed and the newly requested processing are prioritized. If the priority of the newly requested process is high, the process being executed is interrupted / saved and a new request is accepted, and if the priority of the process being executed is high, the process is executed. An interrupt control means for continuing is provided.

Further, in the above-mentioned configuration, it is desirable that a means for generating a template bitmap data used as an template for creating an image, and a plurality of pages of the template bitmap data are stored in the memory. Means for reading in page units as needed and means for creating bitmap data of an image requested by the host computer by applying image drawing processing to the template bitmap data are provided.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic structure of a rasterizer 1 which is an image processing apparatus according to an embodiment of the present invention. The rasterizer 1 has a SCSI adapter 7 and is connected to the host computer 2 by a SCSI cable 3. The center of rasterizer 1 is CPU4 / RAM5
A microprocessor system consisting of ROM6. SCSI adapter 7, DM on the system bus 10
A controller 8, interrupt controller 9, image drawing circuit 11, font expansion circuit 12, scaling circuit 1
3, the compression / expansion circuit 14, and the memory controller 15 are connected. The image drawing circuit 11, the font expansion circuit 12, the enlargement / reduction circuit 13, the compression / expansion circuit 14, and the memory controller 15 are also connected to the image bus 17, and the image bus 17 serves as an image as a temporary storage area for bitmap data. The memory 16 is connected.

The CPU 4 communicates with the host computer 2 via SCSI to receive image information in a page description language format to be processed, a process of controlling each circuit unit to develop a bitmap, a generated bitmap. It controls data processing and sequence control as the rasterizer 1, such as memory management processing for storing data in the image memory 16 and processing for transferring bitmap data to the host computer 2.

The DMA controller 8 executes DMA between the host controller 2 and the RAM 5, and cooperates with the memory controller 15 to execute DMA between the system bus 10 side and the image memory 16. When there is an interrupt request from the host computer 2, C
The PU 4 analyzes the interrupt request, determines the priority of the process currently being executed and the interrupt request, and the interrupt controller 9 controls how to proceed based on this.

The image drawing circuit 11 develops an image of a portion excluding the character code information in the image information expressed in the page description language into bitmap data. The font expansion circuit 12 converts the character code information portion into a character font, and the image drawing circuit 11
Will be added to the bitmap data generated by. The image drawing circuit 11 and the font expanding circuit 12 generate bitmap data on the image memory 16.

The scaling circuit 13 includes an image memory 16
Enlarge or reduce the above bitmap data as needed. The compression / expansion circuit 14 compresses the bitmap data on the image memory 16 in order to reduce the redundancy, and restores (expands) the compressed data. The memory controller 15 is a circuit that controls access to the image memory 16, and also serves as a data path between the system bus 10 side and the image bus 17.

As a matter of course, in the bitmap data,
Size information that the image is composed of vertical m dots and horizontal n dots is always attached. This vertical m dot
The amount of data is also clear from the size information of horizontal n dots. Therefore, in the present invention, a large-capacity memory is used as the image memory 16 so that a large number of pages of bitmap data can be stored if it is normally handled, and the image drawing circuit 11 and the font expansion circuit 12 are used to The CPU 4 manages the storage position of the bitmap data of each page on the image memory 16 based on the size information of the bitmap data of each generated page. In other words, the CPU 4 creates an image memory management table, creates a management table of the data amount of the bitmap data of each page and the start address of the storage position, and stores the bitmap data of a plurality of pages on the image memory 16 without any gaps. Is going.

An example of the memory management is shown in FIG. In this example, the bitmap data of page 1 is stored in the area from address a to address b, the bitmap data of page 2 is stored in the area from address b + 1 to address c, and the subsequent address c
Bitmap data of page 3 is stored in the area from +1 to address d. Next, the bitmap data of page 4 created by the image drawing circuit 11 and the font developing circuit 12 is stored in the area after that, with the address d + 1 as the start address.

As described above, the image memory 16 stores the bitmap data of a large number of pages, and the CPU 4 manages the storage positions of the bitmap data of each page. Therefore, data can be read from the image memory 16 and transferred in page units in response to a request from the host computer 2.

If another request for processing is received from the host computer 2 while the bitmap data expansion processing is being executed, the priority order of the processing being executed and the newly requested processing is determined and a new processing is newly made. If the priority of the requested process is high, the process being executed is interrupted, necessary data are saved, and a new request is accepted and the process is started. Then, when the interrupt processing is completed, the saved data is restored and the interrupted processing is restarted. When interrupting the process being executed by an interrupt,
When it is necessary to move the bitmap data being drawn and created in the image memory 16 to another position for the sake of memory management, if the compression / expansion circuit 14 compresses it in accordance with the moving process, Will occupy less space elsewhere. Of course, when resuming the processing, it is sufficient to decompress the data saved in another location and saved and then decompressed by the compression / decompression circuit 14 and then written in the drawing work area. If the priority of the process being executed is higher than that of the interrupt request, the process is continued. If the host computer determines the interrupt processing or the like, the load on the rasterizer, which is an image processing apparatus, is reduced, and the processing can be speeded up.

Further, in this embodiment, template bitmap data used for creating an image can be generated as a template, and the template bitmap data for a plurality of pages can be stored in the image memory 16. . In response to a request from the host computer 2, bitmap data is generated based on the information in the page description language format in the same manner as described above, and the data is stored and saved as a model in a specific area of the image memory 16. An identification name is given to the template data, and the position in the image memory 16 where the data is stored is managed as a template management table.

In the example of FIG. 2, the bitmap data of the template F1 is stored in the area of the address i to the address j, and the bitmap data of the template F2 is stored in the area of the subsequent addresses j + 1 to k. .
If there is a request from the host computer 2 to draw an image using a model, the data of the specified model is copied to the work area of the image memory 16 and the image drawing processing is added to the model bitmap data. As a result, the bitmap data of the image requested by the host computer 2 is created.

[0022]

According to the image processing apparatus such as the rasterizer of the present invention, a memory having a capacity for storing a plurality of pages of bitmap data, which is a temporary storage area of the bitmap data, and the bitmap data of each page. Since the memory management means for managing the storage position of the bitmap data of each page on the memory based on the data amount of the above is provided, the requests for the processing of a plurality of pages are collectively received from the host computer and the bits are sequentially bit by page. The map can be expanded and stored in the memory, and the bit map data can be delivered to the host computer at a suitable time. As a result, the host computer is extremely loosely constrained by the relationship with the rasterizer, and the setup of the entire work can be reasonably assembled, and the overhead of the system is reduced. This effect becomes more remarkable by providing the above-mentioned interrupt control means. Further, by adding the processing function of the template bitmap data described above, it is possible to efficiently generate bitmap data of an image having many fixed parts.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a rasterizer according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram showing a management mode of an image memory 16 in the apparatus of the above embodiment.

[Explanation of symbols]

 1 Rasterizer 2 Host Computer 3 SCSI Cable 4 CPU 5 RAM 6 ROM 7 SCSI Adapter 8 DMA Controller 9 Interrupt Controller 10 System Bus 11 Image Drawing Circuit 12 Font Expansion Circuit 13 Enlarging / Reducing Circuit 14 Compression / Expansion Circuit 15 Memory Controller 16 Image Memory 17 Image bus

Claims (3)

[Claims] 1. An image processing apparatus for receiving image information expressed in a page description language from a host computer, expanding the bitmap information into bitmap data, and transferring the bitmap data to the host computer. A memory having a capacity for storing the bitmap data of a plurality of pages to be a storage area, and a storage position of the bitmap data of each page on the memory based on a data amount of the bitmap data of each page. An image processing apparatus comprising: a memory management unit that manages the image. 2. The method according to claim 1, wherein when another processing request is received from the host computer while the bitmap data expansion processing is being executed, the priority of the processing being executed and the newly requested processing is set. If the priority of the newly requested process is high, the process being executed is interrupted / saved and the new request is accepted, and if the priority of the process being executed is high, the process is continued. An image processing apparatus comprising an interrupt control means. 3. The means for generating template bitmap data used as an template for image creation according to claim 1 or 2, and storing the template bitmap data for a plurality of pages in the memory. And a means for creating page bitmap data of an image requested by the host computer by applying an image drawing process to the template bitmap data. Image processing device.