JPH0464181A - Raster converter for image data - Google Patents

Abstract

PURPOSE:To shorten a time from input to output and to perform a continuous drawing issuing operation by setting either first and second control means on the other side at readout control when the control means on one side is set at write control. CONSTITUTION:A system is comprised in such a way that bit map data developed on a bit map developing part 7 is distributed to two systems, and is buffered. In other words, one system is the one to supply raster data to a drawing issue control part 12 via a graphic processor(GP) 8 that is the first control means, and another system is the one to supply the raster data to the drawing issue control part 12 via a GP 9 that is the second control means, and the GPs 8 and 9 perform operations in parallel, and the means on the other side performs the readout of the data from raster memory 10, 11 while the means on one side performs write on the raster memory 10, 11. Thereby, it is possible to reduce waste time when making access the raster memory 10, 11, and to perform the continuous drawing issuing operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to image data processing, which converts vector data generated by drawing commands etc. from a host computer and vector data supplied from a CAD system into raster data. The present invention relates to a raster conversion device.

[Prior Art] Image data composed of vector data is printed on electrostatic printers, thermal printers, LED printers, and
In order to output to a raster type output device such as an RT display (well, it is necessary to use a raster conversion device to convert vector data to raster data. Conventionally, this type of raster conversion device converts vector data into For example, DDA
(digital dlfferentlal anal
raster data is obtained by sequentially reading from the bitmap memory. That's what I do.

On the other hand, when storing, for example, an AO size drawing at a resolution of 400 dots/inch, the required bitmap memory capacity reaches 30 Mbytes. For this reason, AI
If a bitmap memory that supports all pixels is used in a large drawing device such as AO size or AO size, the cost will increase significantly.

Therefore, a banding-based rask conversion device that divides one drawing into multiple bands and performs bitmap expansion on a band-by-band basis reduces the amount of bitmap memory used to, for example, about 2M bytes. is also known.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional rask output device, in both the all-pixel correspondence method and the banding method, the time required to develop vector data into a bitmap and write it to the bitmap memory, There is a problem in that a lot of time is spent reading bitmap data from the bitmap memory, and it takes a very long time from inputting vector data to obtaining raster output.

Further, in the case of the conventional banding method, for the same reason, there was a problem in that the drawing operation stopped for each band, making it impossible to perform the drawing operation smoothly.

The present invention has been made in view of such problems, and includes:
It is an object of the present invention to provide an image data rask output device that can significantly shorten the time from input of vector data to output of raster data and can perform smooth drawing operation.

[Means for Solving the Problems] An image data rask output device according to the present invention includes a first
and a second bitmap memory, write control for expanding vector data into bitmap data and writing it into the first bitmap memory, and writing the bitmap data written into the first bitmap data as raster data. a first control means for performing read control for reading; a write control for developing vector data into bitmap data and writing it into the second bitmap memory; and bitmap data written in the second bitmap data. and a second control means that performs read control to read out the data as raster data, and the first and second control means perform read control while one of them performs write control. It is characterized by being something.

[Function] According to the present invention, during a period in which one of the first and second control means is performing write control on one bitmap memory, the other control means is controlling writing on the other bitmap memory. Since the readout is controlled from , bitmap data development and raster output can be executed simultaneously and in parallel.

Therefore, the time from inputting vector data to outputting raster data can be significantly shortened.

Furthermore, according to the present invention, while raster output is being performed from one bitmap memory, bitmap development is being performed on the other bitmap memory, so the raster output is switched to the other bitmap memory. When this occurs, raster output can be started immediately, and continuous drawing operation without stagnation can be performed.

[Embodiments] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a functional block diagram showing an image data rask transform apparatus according to an embodiment of the present invention.

Plotting commands (plotter commands from various manufacturers) given from a host computer etc. are stored in an input data buffer 2 via an interface circuit 1. The drawing commands stored in the input data buffer 2 are sequentially supplied to the command analysis section 3.

The command analysis section 3 analyzes a given drawing command based on the drawing control information given from the key panel 4, and the analysis result is supplied to the vector data conversion section 5. The vector data conversion unit 5 converts the given command analysis result into vector data. The obtained vector data is temporarily stored in the vector data buffer 6.

The vector data stored in the vector data buffer 6 is supplied to a bitmap expansion section 7. The bitmap expansion unit 7 performs bitmap expansion on the vector data in units of bands.

The bitmap data developed by the bitmap development section 7 is distributed into two systems and buffered. That is, one system is a system that supplies raster data to the drawing control unit 12 via a graphic processor (hereinafter referred to as GP) 8, which is a first control means, and in this system, a buffer memory of 2M bytes is used. raster memory 1, which is a bitmap memory with a bandwidth of capacity
0 is used. Another system is a system that supplies raster data to the drawing control unit 12 via the GP9, which is the second control means, and in this system, a buffer memory with a bandwidth of 2M bytes is used. A raster memory 11, which is a map memory, is used. The GPs 8.9 operate in parallel, and while one writes to the raster memory 10.11, the other reads data from the raster memory 10.11. Note that, as the GP8.9, for example, μPD72120 of Nippon Electric Co., Ltd. is suitable.

FIG. 2 is a block diagram showing an example of a hardware configuration for realizing the apparatus shown in FIG. 1.

In this device, two CPUs (central processing units) 21 and 22 are connected via GP8.9.

The CPU 21 executes processing such as command analysis, vector data conversion, and bitmap expansion. Also, CPU22
executes drawing control for a rask output device (not shown) via the driver 24. A communication memory 23 connecting the CPUs 21 and 22 is used for communication between the CPUs 21 and 22 to notify the other party of the completion of each other's processing.

Note that in FIG. 2, the parts designated by the same reference numerals as in FIG. 1 are the same as those in FIG.

Next, the operation of the rask transform apparatus according to this embodiment configured as described above will be explained.

First, in FIG. 1, when a plotting command is input from the host side via the interface circuit 1, this plotting command is stored in the input data buffer 2.

When a predetermined number of drawing commands are stored in the input data buffer 2, the command analysis section 3 is activated and the key panel 4 is activated.
The command is analyzed based on the drawing control information instructed by.

Subsequently, the vector data converter 5 is activated, and vector data constituting image data is generated from the analysis result of the command analyzer 3. Here, as shown in Figure 3, a banding method is adopted in which one piece of image data is divided into n pieces of band data from #1 to #n, and a bitmap is developed for each band. . Therefore,
For example, as shown in FIG. 4, the generated vector data 3
1, band information 32 including the band information 32 is added to each band information 32. The vector data converted here is sequentially stored in the vector data buffer 6.

When the command analysis section 3 analyzes the drawing command, or when the P-OUT-key is pressed on the key panel 4, the bitmap development section 7 is activated.

FIG. 5 is a schematic diagram for explaining the processing in the bitmap development section 7.

The bitmap development section 7 first develops the vector data of band No. #1 into a bitmap, as shown in FIG. 5(a). The expanded bitmap data is GP8
The data are stored in the raster memory 10 under the control of the. When all the vector data of band No. #1 has been developed, the bitmap development section 7 notifies the drawing control section 12 of the completion of development, and starts bitmap development of the vector data of the next band No., #2. .

When the bitmap expansion of band No. #2 starts,
As shown in FIG. 5(b), the developed bitmap data is now stored in the raster memory 11 under the control of the GP 9.

On the other hand, when the drawing control unit 12 receives the notification of the completion of the expansion from the bitmap expansion unit 7, it immediately requests the GP8 to output data, so the GP8 transfers the band number from the raster memory 10 to the drawing control unit 12. Supply #1 raster data.

Therefore, at this time, the bitmap expansion of band No. #2 and the output of band No. #1 are performed simultaneously and in parallel.

When the drawing is completed, the drawing control section 12 notifies the bitmap development section 7 of the completion of drawing. Similarly, when the bitmap development is completed, the bitmap development section 7 notifies the drawing control section 12 of the completion of the development. The bitmap processing time is determined by the amount of data to be processed.
When both bitmap development and drawing processing are completed, the next bitmap development and drawing processing are started.

That is, in the next process, as shown in FIG. 5(C), the bitmap data of band No. #3 is developed under the control of GP8, and at the same time the bitmap data of band No. #2 is expanded. The drawing will be issued under the control of GP9.

Thereafter, similar operations are performed alternately for all bands, and in GP8, #1. #3, #5.・・・
・, Raster conversion of #n-1 band data is also performed by G
In P9, #2. #4. Each receiver has raster conversion of band data of #6° . . . , #n.

According to the apparatus of this embodiment, as shown in FIG. 6, while bitmap data is being written to one of the raster memories 10 and 11, bitmap data is being read from the other. , the wasted time of accessing the raster memories 10 and 11 is significantly reduced, and continuous output of drawings becomes possible by alternately and continuously outputting band data in raster form from the raster memories 10 and 11.

In addition, in this device, vector data has band information, so by not developing vector data with different band numbers into bitmaps, processing efficiency can be further improved, resulting in faster processing. is possible.

In this embodiment, the execution of bitmap expansion is controlled based on the band information added to vector data. The GP may grasp the No. and control the execution of the bitmap expansion.

Furthermore, in the above embodiments, the raster memory only has a capacity of a predetermined bandwidth, but these may be made into full bitmaps.

In this case, by outputting the previous page from the other bitmap memory while bitmap expansion is being performed on one bitmap memory, for drawings spanning multiple pages in the same way as above, Continuous drawing operation can be performed.

[Effects of the Invention] As described above, according to the present invention, the first and second
When one of the control means is set to write control, the other is set to read control, so bitmap data expansion and raster output can be executed simultaneously in parallel, and vector data The time from inputting data to outputting raster data can be significantly shortened, and continuous drawing operation without stagnation can be realized.

[Brief explanation of the drawing]

Fig. 1 is a functional block diagram of an image data vector conversion device according to an embodiment of the present invention, Fig. 2 is a block diagram showing a specific hardware configuration of the device, and Fig. 3 is a processing unit of the device. Fig. 4 is a schematic diagram showing vector data developed by the same device, Fig. 5 is a schematic diagram to explain the parallel operation of GP in the same device, and Fig. 6 is a schematic diagram showing the same. FIG. 3 is an operation timing diagram of the device. 1; Interface circuit, 2; Input data buffer,
3; Command analysis unit, 4; Key panel, 5; Vector data conversion unit, 8; Vector data bath sofa, 7; Bitmap expansion unit, 8.9; Graphic processor, 10.
11; raster memory, 12; drawing control unit, 21, 22;
CPU 123; Communication memory, 24; Driver, 31;
Vector data, 32; band information

Claims (2)

[Claims] (1) First and second bitmap memories, write control for expanding vector data into bitmap data and writing it to the first bitmap memory, and a bitmap written to the first bitmap data. a first control means that performs read control to read data as raster data; write control to develop vector data into bitmap data and write it to the second bitmap memory; and write control means to perform write control to read the data as raster data; and a second control means that performs read control to read out bitmap data as raster data, and the first and second control means perform write control while one of them performs write control. 1. A raster conversion device for image data, characterized in that the device performs readout control. (2) The first and second bitmap memories are band memories that store bitmap data of a predetermined bandwidth, and the first and second control means alternately store the bitmap data for each band. 2. The image data raster conversion apparatus according to claim 1, wherein the image data raster conversion apparatus processes the image data.