JP2000255120A - Printer control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce cost and to enhance the quality of a printing image due to a printer engine for binary output in a printer control device. SOLUTION: In a printer controller (printer control device) 20, a CPU 4 develops the image data from a host computer 1 in first resolving power as binary image data to store the image data in an RAM 6 and allows a video DMA controller 7 to start DMA operation. The video DMA controller 7 successively reads the binary image data on the RAM 6 to store the same in a line buffer 21. An output pattern generating circuit 22 converts the binary image data from the line buffer 21 to multi-value image data and converts this image data to second resolving power higher than first resolving power and subsequently converts the second resolving power to binary image data to output this image data to a printer engine 10 through an engine I/F 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer control device (generally referred to as a "printer controller") for expanding input image data, outputting the image data to a printer engine such as a laser printer, and executing printing, and in particular, costs. The present invention relates to a technique for improving the gradation by printing at a high resolution without increasing image quality.

[0002]

2. Description of the Related Art In a conventional printer controller,
Processing for outputting image data created on the host computer to the printer engine to execute printing will be described with reference to FIGS.

FIG. 22 is a block diagram showing a configuration example of a printer system using a conventional printer controller. This printer system is composed of a host computer 1, a printer controller 2, and a printer engine 10, and the printer controller 2 and the printer engine 10 are integrated into a printer, but other printers are also included. .

The printer controller 2 includes a host interface (hereinafter, “interface” is abbreviated as “I / F”) 3, a CPU as a central processing unit, a ROM as a program memory 5, and a RAM as a data memory.
6 are mutually connected by a system bus 9 to constitute a microcomputer. Further, a video DMA controller (VDMA) connected to the system bus 9
C) 7 and an engine I / F 8.

[0005] The host computer 1 is connected to the host I / F3, and the printer engine 10 is connected to the engine I / F8. In this printer system,
The user creates image data to be printed by the host computer 1, designates a printer for printing, and issues a print command for the created image data.

When a print command is issued, the host computer 1 converts image data into a command code system that can be interpreted on the printer controller 2 side by software called a printer driver 1a suitable for the connected printer. The converted image data is output to the host I / F 3 of the connected printer.

In the printer controller 2, the host I / O
When reception of the image data to be printed is started in F3, the CPU 4 draws the image data on the RAM 6 according to the code information (program) written in the ROM 5 and develops the image data. Next, after the CPU 4 develops the image on the RAM 6, it issues a print start command to the printer engine 10 to start printing, and outputs the developed image data to the printer engine 10 via the engine I / F 8. To execute printing.

However, usually, when image data is output to the printer engine 10 (video output), an enormous amount of data must be transferred in a short period of time. Speeding up. By performing such processing and operations, it becomes possible to print the image data created by the user.

A video I / F for output to a printer engine is roughly divided into a data through system in which the gradation of image data is expressed by 1 bit as shown in FIG. There is a multi-value system in which the gradation of image data as shown is represented by multi-values. In the example of FIG. 24, the number of gradations of the image data is represented by 4 bits (16 gradations).

In the data through system, a data line for transferring image data is directly connected to a laser diode used when performing image forming processing in a printer engine, and a laser diode is used in accordance with image data from a printer controller. Is directly driven to perform writing.

On the other hand, in the multi-value system, as shown in FIG. 25, a change point of a data line of image data (T
In (1, T2), a difference in data skew occurs because each data line is separately connected. Therefore, a pixel clock for image data transfer is generated on the printer controller side and output on the video I / F. Then, the printer engine synchronizes with the pixel clock, absorbs the difference in data skew, and performs writing with a laser diode.

Therefore, the data through system is mainly used for video I / Fs of laser printers and the like, and printing can be performed by directly controlling the resolution from the printer controller side. It can be said that there is. However, on the other hand, since the number of gradations that can be expressed per pixel is 1 bit, it can be said that the resolution must be further increased in order to enhance the gradation.

On the other hand, in a digital copying machine, since one pixel must be excellent in gradation expression, printing itself is often expressed in multiple values such as 16 gradations or 256 gradations per pixel. .

For this reason, a multi-value video I / F is often used as an I / F when a digital copying machine is used as a printer, and is used for a printer engine excellent in gradation expression within one pixel. ing. However, on the other hand,
As the resolution is increased, it is naturally necessary to use a high-speed pixel clock. Therefore, it can be said that high resolution has a limit.

Next, a description will be given of a technique for, when outputting image data from the printer controller to the printer engine, increasing the resolution of the image data and smoothing it into an edge image. For example, if the image data expanded in the memory by the printer controller is as shown in FIG. 26, the following processing is performed on the image data when the image data is output to the printer engine. Perform

For example, by doubling the resolution in the main scanning direction as shown in FIG. 27 and complementing the dots as shown in FIG.
The resolution can be increased and the edge image can be subjected to smoothing processing. This example is a fattening type smoothing process by complementing dots, but there is also a thinning type smoothing process by deleting dots.

Next, after binarizing the binary image data,
As a technology for printing as value image data, Japanese Patent Application Laid-Open
This technology is described in Japanese Patent Application Publication No. 30384.

According to this technique, the input binary image data is compared with FIG. 4, FIG. 7, or FIG.
By applying a low-pass filter (performing a filtering operation) as shown in (1), the binary image data is multi-valued. With such a configuration, when printing is performed at a resolution higher than the resolution of the input image data, the print image is better than when the input image data is simply enlarged and printed. It can be expressed by density.

Next, as a technique for printing low-resolution input image data at a high resolution, there is a technique disclosed in Japanese Patent Application Laid-Open No. 5-138945. This technique will be described. In this technology, the total capacity of data necessary for printing one sheet (multiplied by the number of gradations and the resolution) is set so as to have the same configuration (for example, an 8-bit gradation 300 DPI image is a 2-bit image). (The total capacity is the same as that of an image with a gradation of 600 DPI.) By applying dither processing, the gradation is reduced and then the resolution is increased. With such a configuration, an effect of enhancing the gradation expression can be obtained.

[0020]

In recent years, with the development of laser printers, various printers have been developed.
For example, a printer equipped with a printer controller so that a digital copier can be used as a printer, or one pixel (1
Each of them is capable of expressing a gradation per dot in a multi-valued manner, and is also referred to as a color laser printer, each having a special color.

In particular, color laser printers are required to print high-quality halftone image data (especially low-density portions) such as image data and graphic data. It is important to represent the value image data.

When color image data is printed by the electrophotographic method, it is preferable to increase the resolution and reduce the amount of change in the dot diameter in order to improve the gradation. It has been experimentally proved that a higher quality image can be obtained than by increasing the number of gradations per dot.

However, when the resolution is increased, an extremely large amount of memory is required for storing the dot data when developing the image data. For example, if the resolution is doubled, it is necessary to increase the resolution in both the main scanning direction and the sub-scanning direction.
It will be doubled.

In order to store A3,600 DPI, binary image data as monochrome data without performing compression processing, about 8 MB is required, whereas color data, 8-bit gradation image data is required. Requires 256 MB to be stored.

In addition to this, 1200 DPI and 2400
If the resolution is increased as in the case of DPI or the memory capacity for two pages is secured for double-sided printing, the memory scale increases, the hardware scale increases, and the cost increases. In addition, the CPU imposes a lot of load on processing related to image development, and the performance is reduced.

Further, in order to reduce the required memory, even when performing compression processing, not only does the load on the CPU increase as the amount of data increases,
When compressing halftone image data such as color data, two-dimensional compression must be performed to increase the compression ratio.
The scale will be large.

As described above, if the image data is to be stored at a high resolution or a high gradation in order to print a high quality image, it can be said that the cost related to the memory and the compression increases.

On the other hand, in the conventional printer controller, the technique of printing with changing the resolution is used only to improve the quality of the edge portion of the text data, and the halftone image data for printing with a color printer or the like is used. The values were developed at the resolution of the image to be finally printed. Accordingly, when importance is placed on gradation, it is necessary to use a printer engine capable of expressing gradation per pixel in multiple values.

The printer engine capable of expressing multi-values is as follows:
As described above, not only is the print quality (image quality) worse than in the case where the change in dot diameter is reduced due to the characteristically high resolution, but also the multi-value print control adjusts the emission power of the laser diode in an analog manner. Therefore, it is very difficult to perform minute control, and further, when the resolution is as high as about 600 DPI, the control becomes almost impossible.

Further, since it is necessary to use a pixel clock on the video I / F, there is a limit in increasing the speed of the printer itself.
There was also a problem that unnecessary noise was radiated.

When the resolution of image data to be developed by a binary printer (a printer capable of expressing gradation per pixel only in binary) is increased, a memory for storing the image data increases. As a result, there was a problem that the cost was increased. As a result, a burden is imposed on the CPU that performs the processing, the time involved in image development increases, and there is a problem that the performance is reduced.

On the other hand, in the case of adopting a system as disclosed in Japanese Patent Laid-Open No. 5-130384, for example, when multi-valued binarized image data is once subjected to area gradation processing such as dither processing, Simply applying a low-pass filter will blur the image. Particularly, in the case of an edge image such as text data, there is a problem that the image is deteriorated by passing through a low-pass filter.

In addition, since the area gradation processing is performed, the gradation data in the dither matrix changes because the information of the pixel of interest does not take into account the information that originally has meaning. There is also a problem that the density inversion occurs and the continuity and gradation of halftone data are lost.

In a system as disclosed in Japanese Patent Application Laid-Open No. 5-138945, if the value obtained by multiplying the number of gradations and the resolution becomes the same value, the resolution is increased. Therefore, there is no change in the memory required for image development, so the higher the resolution, the more memory is required, the higher the cost, and the lower the performance There was a problem that it would be done.

The present invention has been made in view of the above-described problems. In a printer control device (printer controller), it is possible to reduce the cost and at the same time, to reduce the number of gradations per pixel (two gradations per pixel). It is an object of the present invention to improve the quality of a printed image by a printer engine (which can be expressed only by a printer engine).

[0036]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a printer control device which expands input image data, outputs the image data to a printer engine, and executes printing. It is characterized by the following.

According to a first aspect of the present invention, there is provided a development processing means for performing development processing for developing input image data as binary image data at a first resolution, and stores the image data developed by the means. Storage means; multi-value processing means for performing a multi-value processing for converting binary image data stored in the means into multi-value image data; and multi-value image data converted by the means. Resolution converting means for converting the image data into a second resolution higher than the first resolution;
It is provided with binarization processing means for performing a binarization process for converting the image data into value image data, and output control means for outputting the binary image data converted by the means to a printer engine.

With this configuration, when the input image data is expanded as image data, the image data is expanded as binary image data at the first resolution (low resolution) and stored in the storage unit. After that, the binary image data is converted to multi-valued image data, and the converted multi-valued image data is converted to a second resolution (high resolution) higher than the first resolution in order to improve the gradation. ), The image data converted to the second resolution is further converted to binary image data, and the converted binary image data is output to the printer engine.
At the same time, the storage capacity of the storage means (memory) for storing the image data is reduced to reduce the cost.
The quality of a print image (halftone density) by the value output printer engine can be improved.

According to a second aspect of the present invention, in the printer control apparatus of the first aspect, the output control means outputs the binary image data converted by the binarization processing means to the printer engine in the main scanning direction. In which pulse width modulation is performed and output as pulse data.
As described above, by performing pulse width modulation in the main scanning direction in which the resolution can be changed relatively easily, printing can be performed at a high resolution without increasing cost.

According to a third aspect of the present invention, there is provided a development processing means for performing development processing for developing input image data as binary image data at a first resolution, and stores the image data developed by the means. Storage means, multi-value processing means for performing multi-value processing for converting binary image data stored in the means into multi-value image data, and a binary image before being converted by the means; Edge detecting means for extracting and detecting edges from the data or the converted multi-valued image data; and converting the multi-valued image data converted by the multi-value processing means to a second resolution higher than the first resolution. And a binarization process for converting the image data converted to the second resolution by the unit into binary image data based on the detection result by the edge detection unit. And binarization means, is provided with a an output control means for outputting the image data of the converted binary by said means to a printer engine.

With this configuration, when the input image data is expanded as image data, the image data is expanded as binary image data at the first resolution and stored in the storage means. The binary image data is converted into multi-valued image data, edges are extracted from the binary image data or the multi-valued image data and detected, and the converted multi-valued image data is converted to a first resolution. Is converted to a higher second resolution, and the image data converted to the second resolution is further converted to binary image data based on the detection result (at this time, for example, divided into an edge image and a halftone image). For the edge image, the edge is emphasized and the smoothing process is performed, and for the halftone image, the density is finely expressed). Since the image data of the value is output to the printer engine, the storage capacity of the storage means for storing the image data is reduced to reduce the cost, and at the same time, the print image (the edge image and the intermediate image) by the printer engine for the binary output is output. Tonal image) can be improved.

According to a fourth aspect of the present invention, in the printer control device of the third aspect, the two-valued data before the conversion is performed by the multi-value processing means.
A line buffer for temporarily storing a plurality of lines of value image data or converted multivalued image data for a plurality of lines, and an edge detecting means for extracting and detecting an edge from the image data stored in the line buffer; It was done.

With this configuration, edges can be extracted and detected from binary or multi-valued image data for a plurality of lines (in the main scanning direction and the sub-scanning direction) stored in the line buffer. Can be expressed.
When performing the binarization process (converting the multivalued image data converted to the second resolution into the binary image data), the output gradation is output from the image data for a plurality of lines stored in the line buffer. Is detected, the halftone image can be accurately represented.

According to a fifth aspect of the present invention, there is provided a development processing means for performing development processing for developing input image data as binary image data at a first resolution, and stores the image data developed by the means. Storage means; multi-value processing means for performing a multi-value processing for converting binary image data stored in the means into multi-value image data; and multi-value image data converted by the means. Resolution conversion means for converting the image data into a second resolution higher than the first resolution, and an area for converting the image data converted to the second resolution into binary image data using an area gradation method The apparatus is provided with area gradation processing means for performing gradation processing, and output control means for outputting binary image data converted by the means to a printer engine.

With this configuration, when the input image data is expanded as image data, the image data is expanded as binary image data at the first resolution and stored in the storage means. The binary image data is converted into multi-valued image data, and the converted multi-valued image data is subjected to a second resolution conversion higher than the first resolution in order to improve the gradation, and the second resolution is further converted to the second resolution. Is converted to binary image data using an area gradation method such as a dither method, and the converted binary image data is output to a printer engine, so that the image data is stored. The storage capacity of the storage means is reduced to reduce the cost, and at the same time, the quality and gradation of the print image (halftone density) by the printer engine for binary output are improved. It is possible to above.

According to a sixth aspect of the present invention, in the printer control device of the fifth aspect, the two-valued data before conversion by the multi-value processing means is provided.
Edge detection means for extracting and detecting an edge from the value image data or the converted multi-value image data is provided, and the area gradation processing means performs area gradation processing based on the detection result by the edge detection means. It is provided with means for changing a threshold matrix (reference pattern) used at that time.

In this way, edges are extracted and detected from binary image data or multi-valued image data, and a threshold matrix used when performing area gradation processing is changed based on the detection result. (For example, by changing a threshold matrix used when performing area gradation processing between an edge of text data or the like and a halftone image), it is possible to improve the print quality of text data by a printer engine for binary output. it can.

According to a seventh aspect of the present invention, in the printer control device of the fifth or sixth aspect, the area gradation processing means is means for performing the area gradation processing so that a plurality of dots are aggregated,
The output control means is means for performing pulse width modulation in the main scanning direction and outputting as pulse data when outputting the binary image data converted by the area gradation processing means to the printer engine.

In this way, high-resolution printing can be performed without increasing the cost. Also, since the pulse output to the printer engine can be performed in a concentrated manner so that the halftone can be expressed well, it is possible to improve the adhesion of the toner at the time of printing by the printer engine and to further improve the gradation. it can.

The invention according to claim 8 is a development processing means for performing development processing for developing input image data as binary image data at a first resolution using an area gradation method,
Storage means for storing the image data expanded by the means; and a threshold matrix used when the expansion processing means performs the expansion processing using the area gradation method with the binary image data stored in the means. Multi-value processing means for performing a multi-value processing for converting to multi-value image data using an area gradation method using a threshold matrix having the same size as the size,
Resolution converting means for converting the multi-valued image data converted by the means to a second resolution higher than the first resolution, and converting the image data converted to the second resolution by the means to binary data It is provided with binarization processing means for performing binarization processing for converting the image data into image data, and output control means for outputting the binary image data converted by the means to a printer engine.

With this configuration, when the input image data is developed as image data, the image data is developed and stored as binary image data at the first resolution using the area gradation method. After memorizing in the means, 2
Value image data is converted to multi-valued image data using the area gradation method using a threshold matrix having the same size as the size of the threshold matrix used in performing the above expansion processing, and the converted multi-valued The image data is converted to a second resolution higher than the first resolution in order to improve the gradation, and the image data converted to the second resolution is further converted to binary image data, and the converted image data is converted. Since the binary image data is output to the printer engine, the storage capacity of the storage means for storing the image data is reduced to reduce the cost, and at the same time, the print image (halftone density) by the binary output printer engine is reduced. ) Quality can be improved. Further, an accurate halftone density can be obtained.

According to a ninth aspect of the present invention, there is provided a development processing means for performing development processing for developing input image data as binary image data at a first resolution, and stores the image data developed by the means. Storage means; multi-value processing means for performing a multi-value processing for converting binary image data stored in the means into multi-value image data; and multi-value image data converted by the means. Resolution converting means for converting the image data into a second resolution higher than the first resolution; extracting a boundary of an image from the image data converted to the second resolution by the means; Area gradation processing means for performing area gradation processing for converting into binary image data using the area gradation method for each enclosed region;
Output control means for outputting the binary image data converted by the means to a printer engine.

According to this structure, when the input image data is developed as image data, the image data is developed as binary image data at the first resolution and stored in the storage means. Converting binary image data into multi-valued image data, converting the converted multi-valued image data to a second resolution higher than the first resolution, and further converting the image data to the second resolution , The boundary line of the image is extracted, and the area surrounded by the extracted boundary line is converted into binary image data by using the area gradation method, and the converted binary image data is output to the printer engine. Output, the cost is reduced by reducing the storage capacity of the storage means for storing the image data, and at the same time, the print image ( It is possible to improve the quality between tone density). In the case of continuous image data of the same density even for halftone density such as graphic data, the boundary line is extracted, and each area surrounded by the extracted boundary line is expressed with uniform density. Therefore, the outline is not blurred, and a high quality print image can be obtained.

In a tenth aspect of the present invention, there is provided a development processing means for performing a development process for dividing input image data into binary image data at a first resolution with a screen angle and dividing the image data into a plurality of color components. Storage means for storing the image data developed by the means;
Multi-value processing means for performing multi-value processing for converting value image data into multi-value image data, and converting the multi-value image data converted by the means to a second resolution higher than the first resolution Resolution converting means for converting the image data converted to the second resolution by the means, and recognizing a screen angle attached to the image data converted to the second resolution by an area gradation method at the same angle as the recognized screen angle. Area gradation processing means for performing area gradation processing for converting the image data into binary image data using the image processing apparatus, and output control means for outputting the binary image data converted by the means to a printer engine. is there.

With this configuration, when the input image data is developed as image data, the image data is converted into binary image data at the first resolution by a screen angle (this is an image processing method such as a color printer). , Which is divided into a plurality of color components, developed and stored in the storage means, and then the binary image data is converted into multi-value image data, and the converted multi-value image is converted. Converting the data to a second resolution higher than the first resolution, further recognizing a screen angle attached to the image data converted to the second resolution, and recognizing the image data at the same angle as the recognized screen angle; Is converted into binary image data using the area gradation method (this is used when performing the area gradation processing so that the angle becomes the same as the screen angle described above). Value pattern is selected), and the converted binary image data is output to the printer engine. Therefore, the storage capacity of the storage means for storing the image data is reduced to reduce the cost, and at the same time to reduce the cost. Can improve the quality and color reproducibility of a print image (halftone density) by the printer engine.

[0056]

Embodiments of the present invention will be specifically described below with reference to the drawings. In each of the embodiments, a color printer controller (hereinafter simply referred to as “printer controller”) and a color laser printer engine (hereinafter simply referred to as “printer engine”) are used. A monochrome laser printer engine may be used.

First, an embodiment of the present invention will be described. FIG. 1 is a block diagram showing a configuration example of a printer system using a printer controller as a printer control device according to an embodiment of the present invention, and portions corresponding to FIG. 22 are denoted by the same reference numerals.

This printer system is composed of a host computer 1, a printer controller 20, and a printer engine 10. The printer controller 20 and the printer engine 10 constitute a printer as a single unit. Including things.

The printer controller 20 has a host I /
F3, a CPU serving as a central processing unit, a ROM 5 serving as a program memory, and a RAM (image storage means) 6 serving as a data memory are mutually connected by a system bus 9 to constitute a microcomputer.

Further, a video DMA controller (VDMAC) 7 connected to the system bus 9, a line buffer 21, an output pattern generation circuit 22, and an engine I / F 8 connected to the output pattern generation circuit 22 are provided. . The host computer 1 is connected to the host I / F 3, and the printer engine 1 is connected to the engine I / F 8.
0 is connected.

In this printer system, the user uses the application software on the host computer 1 to create image data to be printed. At this time, the image data created by the user may be one that covers a plurality of pages, one that is created as color data, one that contains only text data, graphic data, and image data, or a mixture of these. There are various types of image data, such as those that are being read.

When the creation of the image data is completed, the user selects a printer to be printed from the printers connected to the host computer 1 and capable of printing, and issues a print instruction (print execution instruction). Issue

At this time, a print command from the user includes designation of the number of copies, designation of color or monochrome, designation of an enlargement or reduction ratio, designation of a sheet size, and a plurality of pages per sheet. Various print modes are designated, such as designation of whether to perform collective printing for collective printing and designation of use of the toner save function.

When a print command is issued by the user, the printer is connected by software called a printer driver 1a stored in the host computer 1 so as to satisfy various modes specified by the user. The printer controller 20 converts the image data into a code that can be decoded by the printer controller 20 and outputs the converted image data (code information) to the printer controller 20.

In the printer controller 20, a host I / F 3 composed of a network and various interfaces
When the reception of image data from the host computer 1 is started, an interrupt is generated to notify the CPU 4 that a print command has been issued, and the received image data is buffered in the RAM 6 and temporarily stored. .

The CPU 4 develops the received and buffered image data in the RAM 6 according to the code information stored in the ROM 5 so that the image data can be printed by the printer engine 10 at a preset first resolution. Image data received as code information is converted into bitmap information (image data) and stored. that time,
The CPU 4 develops the image in the RAM 6 by virtually dividing the image developing portion into a plurality of bands in the sub-scanning direction. The developed image data is stored in the RAM 6 in band units.

At this time, by the memory management of the RAM 6, for example, as shown in FIG.
The image is developed in the empty area, but it is not necessary to group each color component.

By repeating such processing, one of the image data received by CPU 4
When the image development for the page is completed, the CPU 4 detects the state of the printer engine (color printer engine) 10, and if it is in the ready state, issues a print start command to the printer engine 10 to execute the printing operation. .

Here, when developing the input image data into an image, the CPU 4 performs a binarization process on the image data by using, for example, an area gradation method (development as binary image data). . The area gradation method includes, for example, a dither method. When a binarization process (dither process) is performed using the dither method, a dither pattern (dither matrix) that is a threshold matrix as illustrated in FIG. Use

The same dither pattern is continuously connected to the same pattern, and is referred to virtually in all areas of the page. The numerical value of the dither pattern represents a threshold value. The threshold value is compared with the density value of the actual image data. If the density value of the image data is larger than the threshold value, the pixel is set to a dot. Yes (black)
If the density value of the image data is smaller than the threshold value or each value is the same value, it is determined that there is no dot (white) and R
Store it in AM6.

In this example, in order to represent 64 gradations, the size of the dither pattern is set to 8 × 8 and 64 pixels are used, but the size of the dither pattern may be any size. However, as the size of the dither pattern is increased, the number of gradations that can be expressed is increased, and the gradation is improved, but the generated dots are increased.
The number of lines will be low.

When the data of density = 20/64 as shown in FIG. 4, for example, is dithered using the dither pattern of FIG. 3, the result as shown in FIG. 5 is obtained. When a dither pattern as in this example is used, a dot made of an aggregate of a plurality of pixels can be formed, and a gradation can be expressed in a unit area.
In addition, it is possible to change the angle (screen angle) of the arrangement of the dots in the aggregate by changing the dither pattern (in this example, screen angle = 90).
Every time).

The above dither processing (expansion processing)
When the image data input to the printer controller 20 is color data, the image data is divided into a plurality of color components (only all color components are performed), and the binarized image data is stored in the RAM 6. In addition, the binary image data has a screen angle. The CPU 4 issues a print activation command to the printer engine 10 and, at the same time, makes various settings relating to printing, such as the number of image data (image data) transferred and the size of a margin area, to the video DMA controller 7.

When the print start command is issued from the printer controller 20, the printer engine 10 enables the synchronous signal and the gate signal in the main scanning direction and the sub-scanning direction to the printer controller 20 and starts the printing operation. I do. When the printing operation is started, the video DM
The A controller 7 starts the video DMA operation (the operation of directly accessing the RAM 6 to read out the binary image data obtained by developing the image and outputting the binary image data to the printer engine 10 at a high speed), and transfers the binary image data stored in the RAM 6. The data is sequentially output to the line buffer 21 and stored.

The line buffer 21 stores (1
Alternatively, after temporarily storing binary image data (of a plurality of lines), the image data is output to the output pattern generation circuit 22. The output pattern generation circuit 22 converts the binary image data from the line buffer 21 into multi-valued image data, and converts the converted multi-valued image data to a first resolution (RAM 6 To the second resolution (high resolution) higher than the
Further, the multi-valued image data converted to the second resolution is converted to binary image data, and the converted binary image data is output to the engine I / F 8.

The engine I / F 8 outputs the binary image data from the output pattern generation circuit 22 to the printer engine 10 to execute printing. The ROM 5 has a program code for operating the CPU 4,
Font information and the like used for image development of text data are stored. The functions of the expansion processing means and the like in the present invention are realized by the CPU 4 operating according to the program code written in the ROM 5.

Next, the operation of the output pattern generation circuit 22
That is, the operation for enabling printing at the second resolution (in this example, four times the first resolution) higher than the resolution (first resolution) at the time of image development by the CPU 4 is described. A specific description will be given based on FIGS. However, the second resolution does not necessarily have to be four times the first resolution.

FIG. 6 shows the output pattern generation circuit 22 of FIG.
FIG. 3 is a block diagram illustrating a configuration example of FIG. The output pattern generation circuit 22 includes a multi-value conversion circuit (multi-value processing means) 31, a resolution conversion circuit (resolution conversion means) 32, and a comparator 3.
3, a high resolution dither pattern memory 34, a line buffer 35, and a flip-flop circuit (hereinafter referred to as "F / F") 36. The comparator 33 and the high-resolution dither pattern memory 34 function as a binarization processing unit or an area gradation processing unit. Also,
The F / F 36 and the engine I / F 8 function as output control means.

The output pattern generation circuit 22 has such a configuration,
The value image data is input to the multi-level conversion circuit 31. The multi-level conversion circuit 31 performs a multi-level conversion process for converting the input binary image data into multi-level image data. Specifically, for example, the CPU 4 uses a dither pattern having the same size as the dither pattern used when the CPU 4 performs the expansion processing using the dither method (area gradation method), and uses the dither method to generate a multi-valued image. Convert to data. That is,
The density determination is performed in the unit of the matrix size (8 × 8 in this example).

8 × 8 input from line buffer 21
The binary image data (image data) shown in FIG.
In the case shown in (1), since there are 30 pixels with dots (black) with respect to the whole, the density is 30/6.
4 is determined. This density value (multi-valued image data) is input to a resolution conversion circuit 32, where it is converted to a second resolution (high resolution) higher than the first resolution (low resolution), and then to a comparator 33. Is done.

The comparator 33 includes a resolution conversion circuit 32
Is compared with the threshold value of the high resolution dither pattern in the high resolution dither pattern memory 34. In the high-resolution dither pattern memory 34, a threshold pattern in which the main scanning direction is expressed as a dither pattern four times as long as the sub-scanning direction as shown in FIG.

Accordingly, the comparator 33 compares the dither pattern with the density value from the resolution conversion circuit 32, and, for example, converts the binary image data corresponding to the density value into the bit string of FIG. In the case of image data input to the image data, the density value is converted into binary image data as shown in FIG. 9 and is temporarily stored in the line buffer 35 in line units. However, the line buffer 35 has a configuration capable of storing four times as many pixels as the line buffer 21 in the main scanning direction.

The binary image data stored in the line buffer 35 is synchronized with a video clock (video CLK) having a frequency four times as high as a video clock corresponding to a normal resolution (first resolution) (main scanning direction). Pulse width modulation is performed) as the pulse data of the engine I / F 8
Is output to Therefore, for example, when the first resolution at the time of image development is 600 DPI, binary image data is output as pulse data at 2400 DPI, which is four times that of the first resolution.

With this configuration, it seems that the data becomes horizontally long in the main scanning direction. However, a dot generated by a pulse at 600 DPI as shown in FIG. Since the pulse becomes a vertically long dot as shown in FIG. 11, the result is that there is a dither pattern of 64 pixels × 4 in the same area represented by the 8 × 8 matrix of FIG. Thus, as shown in FIG. 12, finer gradation expression is possible with the same area as in FIG.

With the above-described configuration, it is possible to print an image of 2400 DPI even though the RAM 6 required for image development is 600 DPI, and it is possible to print a fine network by devising a dither pattern. Since it is a point, it is possible to express gradation by increasing the number of lines.

In this embodiment, pulse width modulation is performed in order to increase the resolution. However, the control in the sub-scanning direction is performed mechanically by a general printer engine, not limited to color. In order to convert the resolution, it is necessary to adopt a method of reducing the printing speed (printing speed) or increasing the number of rotations of a polygon mirror (rotating polygon mirror for performing main scanning of a laser beam).

Reducing the printing speed not only lowers the performance of the printer, but also performs mechanical control such as reducing the number of rotations of the motor, so that it is very difficult to achieve one accuracy. In order to increase the number of rotations of the polygon mirror, it is necessary to rotate the polygon mirror at high speed. Therefore, it is necessary to stabilize the image quality by keeping the rotation speed constant, which also requires difficult control.

On the other hand, when the printer engine 10 according to the present embodiment employs the data through system, data is present (colored) as shown in FIG.
Only at the time, it is sufficient to generate a pulse on the data line, so that the control is relatively easy. Therefore, how finely this pulse can be generated is a point for determining how high the resolution can be output.

FIG. 14 shows the output pattern generation circuit 22 of FIG.
FIG. 7 is a block diagram showing another configuration example, and portions corresponding to FIG. 6 are denoted by the same reference numerals. 14 is different from FIG. 6 in that a selector 41 is provided between a comparator 33 and a line buffer 35, and smoothing is performed between the output side of the line buffer 21 and the input side of the selector 41. A circuit 42 is provided, and an edge detection circuit (edge detection means) is provided on the output side of the line buffer 21.
43 is provided.

Here, unlike the halftone image data, as shown in FIG. 15, dots are not formed at a uniform density, but the image data is developed as an edge image. have. Utilizing this property, the output pattern generation circuit 22 is configured as shown in FIG.
That is, the edge detection circuit 43 performs processing of extracting and detecting an edge from binary image data of a plurality of lines (determining whether or not the image data is an edge portion).

The line buffer 21 temporarily stores the binary image data before conversion by the multi-level conversion circuit 31 for a plurality of lines. Output side (multi-level conversion circuit 3
1 and the resolution conversion circuit 32 or between the resolution conversion circuit 32 and the comparator 33).
The multi-valued image data converted by 1 or the multi-valued image data converted to the second resolution by the resolution conversion circuit 32 may be temporarily stored in the line buffer 21 for a plurality of lines.

When the edge detection circuit 43 performs edge detection, for example, if the output data of the line buffer 21 is the data as shown in FIG. 15, there is no data (white) area and there is data (color Note that the region is clearly separated from the region.

When the edge detection circuit 43 determines that the output data of the line buffer 21 is an edge portion, the selector 41 changes the output of the comparator 33 to the output of the smoothing circuit 42, and outputs the output data of the smoothing circuit 42. Is selected, output to the line buffer 35 and stored, and thereafter the same processing as described above is performed.

When the image data as shown in FIG. 15 is input, the smoothing circuit 42
As shown in FIG. 15, the pixels are expanded four times in the main scanning direction (in this example, the pixels are expanded four times, but may be expanded any number of times. In addition, the image data in FIG. H, 1)
To coordinates (F, 5)), coordinates (G, 2 "") and coordinates (F, 4 "") shown in FIG.
A dot is complemented to a pixel which can smooth an edge portion by adding a dot as shown in FIG.

In this example, the processing in the direction of thickening the edge portion is performed. However, the dot of the pixel at the coordinates (G, 3) or (F, 5) is deleted and smoothed, May be performed.

With the above configuration, the RA
Although the M (memory) 6 is configured with only the capacity corresponding to the low resolution (first resolution), the halftone image data and the edge portion are separated to perform image processing suitable for each characteristic. Thus, printing at a high resolution (second resolution) becomes possible. At this time, by sharing the line buffer shown in FIG. 1 and FIG. 14, it is possible to refer to the image data in the sub-scanning direction, and the density determination and the edge detection can be performed easily and efficiently. Can be done.

By the way, in an electrophotographic printer engine widely used in laser printers, digital copying machines, and the like, a powdery ink, which is called a toner and has a reverse potential, is attached to a photoreceptor that has been exposed and charged with static electricity. Let me
The printing operation is carried out by fusing and fixing by heat or pressure after transferring to paper, but the property that when the toner adheres to the photoreceptor, the smaller the dot diameter that adheres, the more difficult it is to adhere. is there.

This is equivalent to the fact that the higher the resolution of the image data and the smaller the pulse width at the time of output, the more difficult it is for toner to adhere to the image data. Another characteristic is that it is easy to adhere if other toner adheres to the surface. When adjusting the density with high resolution, for example, as shown in FIG. 17, a pulse is applied to a position distant from the surrounding dots. By generating a pulse at a place closer to the surrounding dots as shown in FIG. 18 than by generating the toner, the toner can be attached, so that higher quality printing can be performed.

This does not depend only on the pulse in the main scanning direction, but the same can be said for the toner adhesion amount in the sub-scanning direction. As a result, the high resolution as shown in FIG. By using the dither pattern of (1), the amount of toner adhered to the periphery can be gradually increased in order to adjust the density with high resolution (the dither processing is performed so that a plurality of dots gather). As a result, the gradation of the halftone image density is improved.

As described above, when the CPU 4 determines the density at the time when the multivalued circuit 31 converts the image data once binarized by the CPU 4 into a multivalued image, the binarization process (expansion process) is performed. By using a dither pattern of the same size as the used dither pattern (threshold matrix), correct density determination can be made, and when outputting at high resolution, image density can be accurately represented.

Further, graphic data and the like are shown in FIG.
Although there is a halftone density as shown in FIG. 9, since the boundary lines are often clear, these boundary lines are detected, and only the portion where an image exists is detected using the boundary lines as boundaries. The density can be determined in the area. In this example, the density is determined to be 24/64 when all 8 × 8 dither patterns are determined to be one. However, if only the density of the area surrounded by the boundary line is determined, the density is determined to be 24/40.
When expressed in four gradations, it can be determined that density = 38/64.

Therefore, when the multi-valued image data converted to the second resolution by the resolution conversion circuit 32 is graphic data, the comparator 33 extracts an image boundary line from the graphic data and extracts the image. Using the dither method (using the high-resolution dither pattern in the high-resolution dither pattern memory 34), it is possible to convert the image data into binary image data for each area surrounded by the boundary line.

In this case, in order to avoid blurring the boundary of the graphic data, the threshold of the high-resolution dither pattern in the high-resolution dither pattern memory 34 is similarly maximized except for the region surrounded by the boundary. Change so that only the enclosed area is dotted. In this example, since the maximum of the threshold value is 63, 63 is set outside the boundary line as shown in FIG. By switching (changing) to such a dither pattern, even if the image data is graphic data, the density can be adjusted at a high resolution without blurring the outline.

If the image data input to the printer controller 20 is color data, the CPU 4 develops the color data as binary image data at the first resolution by dividing the image into a plurality of color components with a screen angle. Therefore, the image data output from the resolution conversion circuit 32 is of course also provided with a screen angle. When the area gradation processing is performed, the comparator 33 outputs the screen data added to the image data from the resolution conversion circuit 32. Recognizing a corner and converting the image data into binary image data at the same angle as the recognized screen angle using a high-resolution dither pattern in the high-resolution dither pattern memory 34 as shown in FIG. Also becomes possible.

When a high-resolution dither pattern as shown in FIG. 8 is used, the screen angle can be formed at the same angle as the screen angle of the original dither pattern of FIG. ), M (magenta), Y (yellow), and K (black) can be expressed in halftone without changing the color when superimposed.

The comparator 33 can also perform dither processing for converting the multi-valued image data converted by the resolution conversion circuit 32 into binary image data based on the detection result of the edge detection circuit 43.
At this time, the dither pattern used when performing the dither processing is changed based on the detection result by the edge detection circuit 43 (for example, the dither pattern is used when performing the area gradation processing on the edge of the text data or the like and the halftone image). Change the dither pattern).

In this embodiment, the CPU 4 and the comparator 33 perform the binarization processing (dither processing) using the dither method. However, the CPU 4 and the comparator 33 perform binarization processing using another method such as the area gradation method. Processing can also be performed. further,
Although the multi-value processing circuit 31 performs the multi-value processing (dither processing) using the dither method, the multi-value processing can be performed using other methods such as the area gradation method.

Further, in the output pattern generation circuit 22 of this embodiment, as shown in FIGS. 6 and 14, a resolution conversion circuit 32 is provided between the multi-value conversion circuit 31 and the comparator 33. As shown in FIG.
Multi-level circuit 31 and high-resolution dither pattern memory 3
A frequency dividing circuit 50 may be provided between 4 and a video clock generating circuit (not shown) (or a system clock generating circuit).

In the case of such a configuration, the resolution of the dither pattern memory 34 higher than the resolution of the
Since the resolution of the data is higher, it is preferable to use different clocks for reading each data. That is, it is only necessary to input a frequency-divided version of the video clock (or system clock) to the multi-level circuit 31. In this case, the frequency dividing circuit 50 can be said to be a resolution conversion unit.

Further, the present invention can be applied to a printer controller which can be used for various image forming apparatuses such as a high-speed color laser printer, a digital color copying machine, a color ink jet printer and the like.

[0111]

As described above, claims 1 and 2 can be used.
According to the printer control device of the invention, the storage capacity of the storage means (memory) for storing the image data is reduced to reduce the cost, and at the same time, the halftone density of the print image by the printer engine for binary output. Quality can be improved. Further, according to the printer control device of the second aspect of the present invention, high-resolution printing can be performed without increasing costs.

According to the printer control device of the third and fourth aspects of the present invention, the cost is reduced by reducing the storage capacity of the storage means for storing the image data, and at the same time, printing is performed by the printer engine for binary output. The quality of the edge image and the halftone image of the image can be improved. Further, according to the printer control apparatus of the fourth aspect, it is possible to accurately represent an edge image.

According to the printer control apparatus of the present invention, the cost is reduced by reducing the storage capacity of the storage means for storing the image data, and at the same time, the printing is performed by the printer engine for binary output. It is possible to improve the quality and gradation of the halftone density of the image.

Further, according to the printer control apparatus of the present invention, the print quality of text data by the printer engine for binary output can be improved. Further, according to the printer control device of the present invention, it is possible to perform printing at high resolution without increasing the cost. Also, since the pulse output to the printer engine can be performed in a concentrated manner so that the halftone can be expressed well, it is possible to improve the adhesion of the toner at the time of printing by the printer engine and to further improve the gradation. it can.

According to the printer control apparatus of the present invention, the cost is reduced by reducing the storage capacity of the storage means for storing the image data, and at the same time, the printing image is output by the printer engine for binary output. The quality of the halftone density can be improved. Further, an accurate halftone density can be obtained.

According to the printer control apparatus of the ninth aspect, the cost is reduced by reducing the storage capacity of the storage means for storing the image data, and at the same time, the print image is output by the printer engine for binary output. The quality of the halftone density can be improved. In the case of continuous image data of the same density even for halftone density such as graphic data, the boundary line is extracted, and each area surrounded by the extracted boundary line is expressed with uniform density. Therefore, the outline is not blurred, and a high quality print image can be obtained.

According to the printer control apparatus of the tenth aspect, the cost is reduced by reducing the storage capacity of the storage means for storing the image data, and at the same time, the print image is output by the printer engine for binary output. The quality of halftone density and color reproducibility can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a printer system using a printer controller as a printer control device according to an embodiment of the present invention.

FIG. 2 is a development process (binarization process) by the CPU 4 of FIG. 1;
FIG.

FIG. 3 is a diagram showing an example of a dither pattern (threshold matrix) used when the CPU 4 of FIG. 1 performs dither processing as binarization processing.

FIG. 4 is a diagram for explaining image data (density value) input to the printer controller 20 shown in FIG.

5 is a diagram illustrating a result when the CPU 4 in FIG. 1 performs dither processing on the image data illustrated in FIG. 4 using the dither pattern illustrated in FIG. 3;

FIG. 6 is a block diagram illustrating a configuration example of an output pattern generation circuit 22 of FIG. 1;

FIG. 7 is a diagram illustrating an example of binary image data output from the line buffer 21 of FIG. 6;

8 is a diagram showing an example of a high-resolution dither pattern according to the invention of claim 5 stored in the high-resolution dither pattern memory 34 of FIG. 6;

FIG. 9 is a block diagram showing the configuration of the invention according to claim 5, wherein the comparator 33 shown in FIG. 6 uses the high-resolution dither pattern shown in FIG. 8 for multi-valued image data corresponding to the binary image data shown in FIG. FIG. 9 is a diagram showing binary image data obtained by performing a related dither process (binarization process).

FIG. 10 is an explanatory diagram showing a relationship between a pulse (binary image data) corresponding to 600 DPI and a dot.

FIG. 11 is an explanatory diagram showing a relationship between a pulse corresponding to 2400 DPI and a dot.

12 is a diagram illustrating an example of binary image data output from the line buffer 35 to the F / F 36 in FIG.

13 is a diagram illustrating a part of a relationship between binary image data output from the line buffer 35 to the F / F 36 in FIG. 6 and pulse data output from the F / F 36 to the engine I / F 8;

FIG. 14 is a block diagram showing another configuration example of the output pattern generation circuit 22 of FIG. 1;

FIG. 15 is a diagram illustrating an example of binary image data (edge part) input to the smoothing circuit of FIG. 14;

16 is a diagram showing a part of the binary image data output from the smoothing circuit 42 when the binary image data shown in FIG. 15 is input to the smoothing circuit 42 of FIG. 14;

17 is a waveform diagram for explaining a relationship between dither processing (density adjustment) by the comparator 33 in FIG. 14 and pulse data output from the engine I / F 8 to the printer engine 10 in FIG.

18 is another waveform diagram for explaining a relationship between dither processing by the comparator 33 in FIG. 14 and pulse data output from the engine I / F 8 to the printer engine 10 in FIG.

FIG. 19 is a diagram for explaining dither processing according to claim 9 by the comparator 33 of FIG. 14;

20 is a diagram showing an example of a high-resolution dither pattern according to the ninth aspect of the present invention stored in the high-resolution dither pattern memory 34 of FIG. 6;

FIG. 21 is a block diagram showing still another configuration example of the output pattern generation circuit 22 of FIG. 1;

FIG. 22 is a block diagram illustrating a configuration example of a printer system using a conventional printer controller.

FIG. 23 is a diagram illustrating a video I / F of a data through system.

FIG. 24 is a diagram for describing a multi-level video I / F.

FIG. 25 is another diagram for describing a multi-level video I / F.

FIG. 26 is a diagram showing a part of image data (image data) developed in a memory by another conventional printer controller.

FIG. 27 is a diagram illustrating a result obtained by performing twice the resolution conversion in the main scanning direction on the image data illustrated in FIG. 26;

FIG. 28 is a diagram illustrating a result of performing a smoothing process (dot complementation process) on the image data illustrated in FIG. 27;

[Explanation of symbols]

 1: Host computer 1a: Printer driver 3: Host I / F 4: CPU 5: ROM 6: RAM 7: Video DMA controller 8: Engine I / F 9: System bus 10: Printer engine 20: Printer controller 21, 35: Line buffer 22: Output pattern generation circuit 31: Multi-value conversion circuit 32: Resolution conversion circuit 33: Comparator 34: High resolution dither pattern memory 36: Flip-flop circuit (F / F) 41: Selector 42: Smoothing circuit 43: Edge detection Circuit 50: Divider circuit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/40 H04N 1/40 103B 9A001 F term (Reference) 2C087 AA16 AB05 AC08 BC05 BD24 BD46 2C262 AA05 AB07 AB09 AC17 DA16 EA03 5B021 AA01 AA02 CC05 DD02 DD12 LG08 LL05 5C076 AA21 AA27 AA32 BA08 BB44 5C077 LL17 LL19 MP02 MP06 MP08 NN09 PP02 PP20 PP27 PP43 PP65 PP68 PQ08 PQ20 PQ22 RR04 RR07 HR09 RR10 RR10 HRR

Claims (10)

[Claims] 1. A developing process for expanding input image data as binary image data at a first resolution in a printer control device for expanding input image data, outputting the image data to a printer engine, and executing printing. Processing means for performing the image processing, storage means for storing the image data developed by the means, and multi-value processing for converting the binary image data stored in the means into multi-value image data. Value conversion processing means, resolution conversion means for converting the multi-valued image data converted by the means to a second resolution higher than the first resolution, and conversion to the second resolution by the means Binarization processing means for performing binarization processing for converting the converted image data into binary image data, and converting the binary image data converted by the means into the printer engine Printer control apparatus characterized by comprising an output control means for outputting. 2. When the output control means outputs the binary image data converted by the binarization processing means to the printer engine, the output control means performs pulse width modulation in a main scanning direction and outputs the data as pulse data. 2. The printer control device according to claim 1, wherein the printer control device performs the operation. 3. A developing process for expanding input image data as binary image data at a first resolution in a printer control device which expands input image data, outputs the image data to a printer engine, and executes printing. Processing means for performing the image processing, storage means for storing the image data developed by the means, and multi-value processing for converting the binary image data stored in the means into multi-value image data. Value processing means, edge detection means for extracting and detecting edges from binary image data before conversion by the means or converted multi-value image data, and the multi-value processing means Resolution conversion means for converting the converted multi-valued image data to a second resolution higher than the first resolution, and an image converted to the second resolution by the means. Binarization processing means for performing binarization processing for converting data into binary image data based on the detection result by the edge detection means; and transmitting the binary image data converted by the means to the printer engine. A printer control device comprising output control means for outputting. 4. The printer control device according to claim 3, wherein the binary image data before conversion by the multi-value processing means or the converted multi-value image data is temporarily stored for a plurality of lines. A printer control device, wherein the edge detection means is means for extracting and detecting an edge from the image data stored in the line buffer. 5. A developing process for expanding input image data as binary image data at a first resolution in a printer control device for expanding input image data, outputting the image data to a printer engine, and executing printing. Processing means for performing the image processing, storage means for storing the image data developed by the means, and multi-value processing for converting the binary image data stored in the means into multi-value image data. Value conversion processing means, resolution conversion means for converting the multi-valued image data converted by the means to a second resolution higher than the first resolution, and conversion to the second resolution by the means Area gradation processing means for performing area gradation processing for converting the converted image data into binary image data using the area gradation method, and the binary image data converted by the means. Printer control apparatus characterized by comprising an output control means for outputting to the printer engine. 6. The printer control device according to claim 5, wherein edges are extracted and detected from binary image data before conversion by the multi-value processing means or converted multi-value image data. A printer provided with edge detection means, wherein the area gradation processing means has means for changing a threshold matrix used when performing the area gradation processing based on a detection result by the edge detection means. Control device. 7. The area gradation processing means is means for performing the area gradation processing so that a plurality of dots are gathered, and the output control means is a binary value converted by the area gradation processing means. 7. The printer control device according to claim 5, wherein, when outputting the image data to the printer engine, the image data is pulse width modulated in a main scanning direction and output as pulse data. 8. A printer control device for expanding input image data, outputting the image data to a printer engine, and executing printing, wherein the input image data is converted into a binary image at a first resolution using an area gradation method. Expansion processing means for performing expansion processing for expanding as image data; storage means for storing the image data expanded by the means; and binary image data stored in the means, wherein the expansion processing means Multi-level conversion using a threshold matrix of the same size as the size of the threshold matrix used when performing the expansion processing using the area method, and converting it to multi-value image data using the area gradation method Processing means; resolution conversion means for converting the multi-valued image data converted by the means to a second resolution higher than the first resolution;
Binarization processing means for performing binarization processing for converting the image data converted to the resolution into binary image data, and outputting the binary image data converted by the means to the printer engine A printer control device comprising a control unit. 9. A developing process for expanding input image data as binary image data at a first resolution in a printer control device that expands input image data, outputs the image data to a printer engine, and executes printing. Processing means for performing the image processing, storage means for storing the image data developed by the means, and multi-value processing for converting the binary image data stored in the means into multi-value image data. Value conversion processing means, resolution conversion means for converting the multi-valued image data converted by the means to a second resolution higher than the first resolution, and conversion to the second resolution by the means A boundary line of an image is extracted from the extracted image data, and an area gradation process for converting the image data into binary image data using an area gradation method is performed for each region surrounded by the extracted boundary line. Cormorant area gradation processing unit and a printer control device, characterized in that the image data of the converted binary in said means providing an output control means for outputting to the printer engine. 10. A printer control device for expanding input image data, outputting the image data to a printer engine, and executing printing, wherein the input image data is given a screen angle as binary image data at a first resolution. Expansion processing means for performing expansion processing by dividing the image data into a plurality of color components, storage means for storing image data expanded by the means, and multi-valued binary image data stored in the means. Multi-value processing means for performing multi-value processing for converting to image data, and resolution converting means for converting the multi-value image data converted by the means to a second resolution higher than the first resolution. Recognizing a screen angle attached to the image data converted to the second resolution by the means, and converting the image data at the same angle as the recognized screen angle. Area gradation processing means for performing area gradation processing for converting to binary image data using a product gradation method, and output control means for outputting the binary image data converted by the means to the printer engine And a printer control device.