JP2001136373A - Image processor and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processor and an image forming device facilitating handling of image data by equalizing respective data widths of the image data developed by plural resolution. SOLUTION: Inputted image information is developed by the resolution higher than basic resolution except for the basic resolution and a high resolution bit map pattern is coordinated with a prescribed number of pattern numbers to execute conversion to equalize the data width of pattern data expressing the pattern number with the data width of density data of data developed by the basic resolution to equalize the data width of image data developed by the basic resolution with that of image data developed by high resolution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image processing apparatus and an image forming apparatus, and more particularly, to characters input in a page description language (PDL) or the like in a printer connected to a computer or a printer connected to a network. The present invention relates to an image processing apparatus that converts information and graphic information into image data expanded at a plurality of resolutions, and an image forming apparatus that outputs a high-quality print image using the data converted by the image processing apparatus.

[0002]

2. Description of the Related Art Many computer printers and network printers that are currently commercialized convert character codes into bitmap images of a printer before printing coded character information. This is to match the bit configuration on the computer side with the bit configuration on the printer side.It is determined whether the character code sent from the computer is dot-printed or not in the resolution unit of the printer. A bitmap image is generated based on the bitmap image. Even if the printer itself is a multi-valued printer capable of expressing a halftone image (for example, 8 bits, 256 gradations) for each pixel, it is necessary to process a pixel as a bitmap image in which one pixel is assigned to a binary value of 0 or 255. General. As a result, step-like jaggies (jaggies) in the resolution unit of the printer occur at the edges of characters, line drawings, and graphics, deteriorating the image quality.

In order to solve this problem of image quality deterioration, minute pixels finer than the basic resolution are generated, and a pixel of interest (basic pixel) is determined according to how much the object area or background area of the original image occupies the minute pixels. An anti-aliasing process is performed by determining the density level of a pixel having a resolution to make a jagged portion (also called an alias) a visually smooth image. However, in this conventional anti-aliasing process,
Only an alias with a plain background, ie, a white background, which is the color of the transfer medium, can be handled. For example, in the case of black letters on light gray ground, aliases may have white border-like defects after anti-aliasing, or characters, line drawings, and graphic edges may not be treated with anti-aliasing. In this case, a step-like jagging (jagging) occurs in the resolution unit of the printer, and the image quality is degraded. In addition, it is known that, in the conventional anti-aliasing processing, in addition to the above, fine gray lines are broken or crushed by adjacent lines, so that the image quality is easily deteriorated.

Therefore, in order to perform anti-aliasing processing with more emphasis on resolution, Japanese Patent Application Laid-Open No. 7-273994 has been proposed.
Japanese Patent Application Laid-Open Publication No. H11-163873 discloses an image forming apparatus that converts a bitmap image into a bitmap image with a different resolution for each image area, forms an image for each resolution, and superimposes the formed images. However, in this image forming apparatus, since images formed by performing image formation a plurality of times are superimposed, not only does the recording speed decrease in proportion to the number of superimpositions, but also misregistration occurs during superimposition, There is a high possibility that image quality will be greatly impaired.

[0005] In order to solve the problem of such a decrease in recording speed, fine pixels finer than the basic resolution are generated.
A method has been proposed in which on / off information of a minute pixel is mixed with image data of a normally developed pixel and output to an image forming apparatus.

[0006]

However, there is a problem that the image data width is different between a pixel developed into minute pixels and a pixel developed as usual, and the handling of image data becomes complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a first object of the present invention is to make image data developed at a plurality of resolutions equal in data width to facilitate handling of image data. An object of the present invention is to provide an image processing apparatus and an image forming apparatus.

A second object of the present invention is to provide a character on a background color,
It is an object of the present invention to provide an image processing apparatus and an image forming apparatus which do not cause a defect even when the resolution of development of a line drawing, a graphic or the like is increased.

A third object of the present invention is to provide an image processing apparatus and an image forming apparatus which can form an image without impairing the recording speed and image quality with a simple configuration.

[0010]

According to the present invention, there is provided an image processing apparatus for converting input image information into image data of a form used for image formation in an image forming apparatus. A first expansion unit that expands input image information into first expansion data in pixel units of a first resolution; and arranges input image information in pixel unit data of a second resolution higher than the first resolution. Conversion to a pattern data corresponding to the array pattern representing the area of the first resolution pixel unit and having a data width within the data width of the density data representing the density of the first developed data. It is characterized by comprising processing means and identification code adding means for adding an identification code indicating whether or not the data includes the pattern data.

According to a second aspect of the present invention, in the image processing apparatus according to the first aspect, the conversion processing means expands the input image information into second expanded data in pixel units of a second resolution. Converting means for converting an array pattern of the second developed data representing the pixel area of the first resolution into pattern data having a data width within a data width of density data representing the density of the first developed data; , Is characterized by having.

According to a third aspect of the present invention, in the image processing apparatus according to the second aspect, the conversion means performs conversion using a look-up table representing a pattern number assigned to an array pattern of the second expanded data. It is characterized by the following.

According to a fourth aspect of the present invention, in the image processing apparatus according to the second or third aspect, based on the color information included in the input image information, the first expanded data is converted into density data for each color. When the first image data is converted to the first image data and the second expanded data representing the first resolution pixel unit area are all the same, the second expanded data are all the same area in the first resolution pixel unit. Characterized in that it has information combining means for converting the data representing the image data into the first image data.

According to a fifth aspect of the present invention, there is provided an image forming apparatus, comprising: the first image data transmitted from the image processing apparatus according to the first aspect and obtained from the first expanded data; An image forming apparatus capable of outputting at a plurality of resolutions based on two types of image data of second image data including pattern data, wherein the second image data is selected based on an identification code, and A pixel for converting pattern data included in the second image data into an array pattern of data in pixel units of the second resolution and obtaining density data of pixels of the second resolution constituting the array pattern obtained by the conversion. A decoder for generating density reference direction data;
The second pattern forming the array pattern is based on the density data of the pixels located in the reference direction indicated by the pixel density reference direction data.
Density determining means for determining the density of the pixel of the resolution.

According to a sixth aspect of the present invention, in the image forming apparatus according to the fifth aspect, when the density determining means does not have density data of a pixel located in the reference direction indicated by the pixel density reference direction data, And determining the density of the pixels of the second resolution constituting the array pattern based on the density data of the pixels different from the reference direction.

According to a seventh aspect of the present invention, in the image forming apparatus according to the fifth or sixth aspect, a screen for generating a plurality of screen signals corresponding to the density data of the second resolution pixel determined by the density determining means. A modulation signal is generated by synthesizing a signal generation unit, a screen signal generated by the screen signal generation unit, and a serial signal obtained by performing parallel-serial processing on an array pattern of pixel-based data of the second resolution. And synthesizing means.

According to an eighth aspect of the present invention, in the image forming apparatus according to the seventh aspect of the present invention, the synthesizing means corresponds to the density data determined by the density determining means for the pixels of the second resolution constituting the array pattern. There is provided a selecting means for selecting and outputting a screen signal from a plurality of screen signals.

According to a ninth aspect of the present invention, in the image forming apparatus according to the seventh or eighth aspect, the synthesizing means includes a screen signal corresponding to density data included in the first image data and a second signal forming an array pattern. A screen signal corresponding to the density data of the two-resolution pixel determined by the density determining means is synthesized and output.

According to a tenth aspect of the present invention, in the image forming apparatus according to any one of the seventh to ninth aspects, the synthesizing unit includes:
It is characterized by being constituted by a logical operation element.

According to an eleventh aspect of the present invention, in the image forming apparatus according to any one of the fifth to tenth aspects, the pixel density reference direction data generated by the decoder is obtained from pattern data included in the second image data. The second resolution is determined based on the pattern distribution of the array pattern of the data of the pixel unit of the second resolution.

[0021]

Embodiments of the present invention will be described below. FIG. 1 is a configuration diagram illustrating an embodiment of an image processing apparatus and an image forming apparatus according to the present invention. (Image Processing Apparatus) The image forming apparatus shown in FIG. 1 includes an image processing apparatus 1 and an image output unit 2.
A plurality of client computers 3A, 3B, ...
A client computer group 3 and another device group 4 including a server computer 4A and another image processing device 4B are connected via a network 5 (hereinafter collectively referred to as a "device group"). The image processing device 1 includes:
A communication control unit 110, a main control unit 120, a magnetic disk device 130, a buffer memory 140, and an output unit control unit 150 are provided. The buffer memory 140 and the output unit control unit 150 are connected to the image output unit 2. Although FIG. 1 illustrates an example in which the image processing apparatus 1 and the image output unit 2 are configured as separate blocks and configured separately, the image processing apparatus 1 and the image output unit 2 may be integrally configured. .

FIG. 2 is a functional block diagram showing an outline of an operation mainly in a data flow in the main control unit. As shown in FIG. 2, the main control unit 120 includes a communication protocol analysis / control unit 121 and a PDL (Page Description).
(ption Language: page description language) It is composed of a command / data analysis unit 122, a threshold table 122b storing threshold values, an image development unit 123, a color determination / operator addition unit 125, and an information connection unit 124. The communication protocol analysis / control unit 121 is connected to the communication control group 110, and the information connection unit 124 is connected to the buffer memory 140.

The components shown in FIGS. 1 and 2 will be described below. In FIG. 1, a network 5 is, for example, Ethernet (trademark of Xerox, USA), and a plurality of protocols operate according to application software of the client computer group 3 and the other device group 4. The communication control unit 110 is an Ethernet CSMA / C
D (Carrier Sense Multiple)
Access / Collision Detect) communication control is performed.

The input image information received by the communication control unit 110 from the client computer group 3 and the other device group 4 is passed to the main control unit 120, and the communication protocol analysis / control unit 121 and the PDL command / data analysis unit 122 After the analysis of the communication protocol and the analysis of the PDL command are carried out in the step (a), the data development processing and the data conversion processing are performed in the image development section 123, and the color determination /
The color information and the like from the operator assigning unit 125 are combined and written into the buffer memory 140 as needed. Details of communication protocol analysis, PDL command analysis, data expansion processing, and data conversion processing will be described later.

The magnetic disk device 130 includes the entire image processing apparatus 1, that is, the communication control unit 110 and the main control unit 12
0, an operation system for controlling the buffer memory 140, the output unit control unit 150, and the like, a device driver, application software, and the like are installed, read out as needed, loaded into a main storage device (not shown), and executed. Further, the magnetic disk device 130
When the capacity of the main storage device and the buffer memory 140 (not shown) becomes insufficient, the buffer memory 140 is also used as a temporary storage area for data. The data processed by the main control unit 120 is temporarily stored in the buffer memory 140. Output control unit 15
0 outputs the image data temporarily stored in the buffer memory 140 to the image output unit 2 in synchronization with the operation of the image output unit 2.

More specifically, referring to FIG. 2, image information input from the communication control unit 110 to the main control unit 120 is transmitted to the communication protocol analysis / control unit 1 of the main control unit 120.
21. Information exchanged by the communication control unit 110 with the client computer group 3 and the other device group 4 includes print information in which scan image information and code information described in PDL are mixed.

In the communication protocol analysis / control unit 121,
The communication protocol of the information input from the communication control unit 110 is analyzed, and the print information described in the PDL among the input information is transferred to the PDL command / data analysis unit 122. The communication protocol analysis / control unit 121 includes a plurality of protocols, for example, TCP / IP, Apple Ta
lk (a trademark of Apple Inc., USA), IPX / SPX, and the like. The communication protocol analysis / control unit 12
When outputting a response to the status investigation request of the image output unit 2 or the like to the client computer group 3 and the other device group 4, the communication protocol control adapted to the client computer group 3 and the other device group 4 is performed. After performing, output to the communication control unit 110.

The PDL command / data analysis unit 122
In accordance with the data in the threshold value table 122b, print information described in various PDLs among the input image information is analyzed and converted into intermediate code data. As PDL, for example, PostScript (PostScript)
t: United States Adobe (trademark, hereinafter referred to as "PS"), Interpress (trademark of Xerox, USA) and the like.
Print information analyzed by the PDL command / data analysis unit 122 and including shape information such as resolution, contour, position, and rotation angle is passed to the image development unit 123. The color information of the command data analyzed by the PDL command / data analysis unit 122 is passed to the color determination / operator assignment unit 125. The threshold value table 122b describes threshold values of objects described in the PDL, such as line width, font size, density information, rotation angle, and the like. The PDL command / data analysis unit 122 performs image development described later. Processing conditions for expansion processing and conversion processing in the unit 123 are allocated.

The image developing unit 123 performs a data developing process and a data converting process based on the processing conditions allocated by the PDL command / data analyzing unit 122, and outputs the processed data to the information combining unit 124.

Next, the operation of the image developing section 123 will be described in detail. FIG. 3 is a functional block diagram illustrating an outline of the operation of the image developing unit 123. As shown in FIG. 3, the image expanding unit 123 includes a resolution converting unit 126, a first expanding unit 127a as a first expanding unit, a converting unit 127b having a second expanding unit 127b1 and a converting unit 127b2, The table group 128 and the font cache 129 connected to the conversion processing unit 127b, and the flag addition units 127c and 127d as identification code addition means
And is composed of

The data transmitted from the PDL command / data analyzer 122 is input to the resolution converter 126. When the processing condition of the input data indicates the expansion processing at the first resolution (24 dpm in the present embodiment), a bitmap frame of the first resolution is generated by the resolution conversion unit 126, and the first expansion processing unit Proceeding to 127a, the input image information is expanded into first expansion data (bitmap) in pixel units of the first resolution. The portion developed at the first resolution can be the background portion of the image in this example. The first expansion data includes a flag adding unit 127
In c, an identification flag indicating that the data has been processed by the first expansion processing unit 127a is added, and the data is output to the information combining unit 124. If there is character information in the input data, data expansion processing is performed with reference to the font cache 129 via the conversion processing unit 127b.

The processing condition of the input data is a second resolution higher than the first resolution (96 dp in this embodiment).
In the case of showing the expansion processing in m), a bitmap frame of the second resolution is generated by the resolution conversion unit 126, and the process proceeds to the conversion processing unit 127b, where the second expansion unit 1 of the conversion processing unit 127b is used.
With reference to the table group 128 and the font cache 129 by 27b1, the input image information is expanded into second expansion data (bitmap) of a pixel unit of the second resolution. The portion developed at the second resolution can be an object portion of the image or the entire image.

As shown in FIG. 5, a part of the table group 128 includes a plurality of adjacent tables (4 in this embodiment).
Lookup table showing an array pattern (bitmap pattern) of a pixel unit of the first resolution represented by data of a pixel unit of the second resolution (16 in 4 rows and 4 columns) and a pattern number corresponding to the array pattern The conversion means 127b2 uses the look-up table to convert an array pattern represented by pixel-based data of the second resolution into pattern data representing the array pattern (pattern number in the present embodiment). Convert to

In the present embodiment, the data width of the pattern data is converted so as to be the same as the data width of the density data representing the density of the first developed data described later. Thereby, the data width of the image data obtained by the expansion of the second resolution can be made equal to the data width of the image data obtained by the expansion of the first resolution, and the handling of the image data becomes easy.

The pattern data obtained by the conversion processing is added to the second expanding means 12 by the flag adding section 127d.
An identification flag indicating that the data has been processed in 7b1 is added to the data and output to the information combining unit 124.

Referring to the flow chart shown in FIG. 4, the procedure of the conversion processing and the conversion processing of the conversion processing unit 127b when the pattern data and the density data are each represented by the same data width of 8 bits will be described more specifically. When the fan-shaped graphic data described in PDL (see FIG. 7A) is input to the image developing unit 123, the image developing unit 123
In the resolution conversion unit 126, a bitmap frame of the second resolution (high resolution) is generated and the coordinate axis is determined (FIG. 4: step S11). As described above, the bitmap frame of the second resolution may be generated within a range where an object such as a character or a graphic exists, or may be generated over the entire screen.
Needs to be synchronized with the bitmap frame of the first resolution used in.

Next, the outline (outline) of the figure represented by a cubic Bezier curve or the like is drawn (FIG. 4: step S12). Next, the contour line is a known straight line approximation method (for example,
A straight line approximation is performed by, for example, a method of repeating a process of generating a new control point at an intermediate point between the control points to perform a straight line approximation (FIG. 4: step S13).

Next, the second resolution bitmap data is
A known generation method (for example, if the area inside a pixel divided by a straight line passing through the bitmap frame occupies more than half, the pixel is turned on, and if less than half, the pixel is turned off. (FIG. 4: Step S)
14).

Next, the generated bitmap is converted into an 8-bit pattern number by a conversion means 127b2 using a look-up table prepared in advance in the table group 128 (FIG. 4: step S15), Is generated, occupying the lower 8 bits of the pattern data.

Next, the above density data will be described.

The color determination operator assigning unit 125 applies the PDL of the first expanded data to the first expanded data based on the color information of the PDL command / data analyzed by the PDL command / data analyzer 122. From the multi-valued image information, YMCK (yellow,
For each color of magenta, cyan, and black), a parameter for generating 8-bit multi-valued image data (density data) representing the density value of each color is generated, and the information combining unit 124
To send to. Also, all solid and all white (that is, all the same)
The second expanded data after the conversion process including the pattern data indicating
Generating a parameter for converting each color of K into first image data including density data representing a density value of each color;
The parameters are sent to the information combining unit 124.

In the information combining unit 124, based on the parameters transmitted from the color judgment operator providing unit 125, the lowermost layer part described in the PDL, that is, the first part of the background part in this example,
First image data including 8-bit density data representing the density value of each color of YMCK is generated from the expanded data, and the first image data of each color is stored in the buffer memory 14.
0 is written to the area for each color of YMCK. next,
Although the second development data of the second layer is overwritten, the second development data after the conversion processing including the pattern data indicating all solid and all white as described above also has the density representing the density value of each color for each color of YMCK. The multi-valued image data is converted into first image data including
Is written in the area for each color. When the first image data of each color is overwritten, an edge flag is added to the first image data that is in contact with the second developed data. In addition,
The edge flag will be described later. When the first expanded data is converted into first image data for each color, screen select data is also added based on the color information of the PDL command / data analyzed by the PDL command / data analysis unit 122. When the second expanded data after the conversion processing is converted into the first image data, similarly, the screen select data is added and the identification flag is also changed.

An attribute flag is given to the converted second expanded data that has not been converted to the first image data according to the characteristics of each object, and is written to the buffer memory 140 as the second image data. . As a result, an identification code indicating that the data includes pattern data is assigned only to the second converted data that has not been converted.

As shown in FIG. 6, the image data generated by the information combining unit 124 has a total of 12 bits of 8-bit image data indicating a density value or a pattern number and 4-bit control data indicating a control signal. Consists of bits.

As described above, the first image data (data B) and the second image data (data A) have different data structures because the process until the image data is formed is different.

The first image data (data B) has a resolution of 24 dpm, which is equal to the basic resolution of the image forming apparatus which is the first resolution.
8-bit (256 gradations) density data developed at a resolution of 2 bits and 2-bit screen select data (S_SEL) for selection by an image signal conversion unit 210 described later.
Is added to the MSB of the data, and the first expansion processing unit 1
27a, which is data converted from the second expanded data, that is, an identification flag 0 indicating that the data does not include pattern data, and an edge flag indicating whether or not the object is a contour part ( 1 or 0).

The screen select data is data used for selecting a screen signal which is an actual display or a print pattern when a display corresponding to the designated density is executed. For example, when displaying or printing at a certain density, several patterns for displaying or printing the density can be selected, and data for selecting one screen signal from the plurality of selectable screen signals is provided. Screen select data. In data B shown in FIG. 6, one of the screen signals is selected from four types of patterns corresponding to 0, 1, 2, and 3 indicated by the S_SEL field based on the screen select data specified in the S_SEL field. .

On the other hand, the second image data (data A) includes 8-bit pattern data representing pattern numbers (0 to 255) for identifying 256 types of array patterns, as exemplified in FIG. An identification flag 1 is added to the MSB of the data and indicates that the data includes the pattern data processed by the second expanding means 127b1, and an attribute flag is provided.

As the attribute flag, for example, 1 is added to an object such as an inverted character, which means that the object side, which is the inside of the object described later, and the background side, which is the outside, are exchanged (FIG. 6). : 10th bit), indicating whether or not there is a colored background outside the object (FIG. 6: 9th bit), indicating whether the object has intermediate color density information (FIG. 6). 6: 8th bit).

For example, if the first resolution is 24 dpm and the second resolution is 96 dpm, the pixels of the second resolution have a size obtained by dividing the pixels of the first resolution into 16 parts. Therefore, the second
An array pattern represented by pixels with a resolution of about 65
000 (2 ¹⁶⁾ present, corresponding to about 6500
Zero pattern numbers are required.

In this embodiment, as a result of examining the frequency of bitmap patterns that appear in advance, it has been confirmed that about 256 types of patterns are sufficient to represent an outline. select the pattern of (2 ⁸ types), made to correspond to 256 pattern number, remaining patterns that were not selected (2 ¹⁶ -2 ^eight pattern), the selected pattern that pattern is approximated Convert to pattern number. By limiting the type of the pattern in this manner, the data width of the pattern data included in the second image data (data A) is reduced to the data width (8 bits) of the density data included in the first image data (data B). It is stored in the same data width as.

With reference to the graphic data shown in FIG. 7, the operation of the image developing unit 123 and the information combining unit 124 will be further described. In this example, the basic resolution of the image forming apparatus is 24 dp
m (first resolution), which is represented by a large matrix in FIGS. 7B and 7C. The higher resolution is 96d
pm (second resolution), which is represented by a small matrix in FIGS. 7B and 7C.

In the fan-shaped graphic data represented by PDL shown in FIG. 7A, the background part is developed at 24 dpm by the first development processing unit 127a, and the object part is developed at 96 dpm by the second development unit 127b1. You. FIG. 7B schematically shows outputs at both resolutions superimposed on each other in accordance with the vertical relationship shown in the PDL. When color information is combined with the developed data by the information combining unit 124, the second developed data including pattern data indicating all solid and all white includes density data representing the density value of each color of YMCK. The image data is converted into the first image data, as shown in FIG.

The fan-shaped graphic data expressed in PDL (FIG. 7A) has an object portion having a halftone density (75%) and a background portion having a halftone density (10%). , 96 dpm are represented by binary data that cannot express halftone density, so that the pixels that are turned on are output at the maximum density, and the pixels that are turned off have no density. As described above, by converting the all-solid and all-white second expanded data into the first image data and outputting the first image data, the part where the pattern data shows all-solid and all-white among the parts expanded at 96 dpm Can be represented by a halftone density as shown in FIG.

As described above, by displaying the object outline at a high resolution of 96 dpm, the PDL is displayed.
Can more accurately reproduce the outline of the graphic data represented by. Further, by appropriately converting the second expanded data into the first image data in accordance with the characteristics of the object, the image density of the graphic data expressed in PDL can be reproduced more accurately.

However, as can be understood from the structure of the second image data shown in FIG. 6, the second image data (data A) does not have areas for storing density data and screen select data. Therefore, density information cannot be held only with the second image data, and the second image data has the second image data as shown in FIG.
In a pixel area output as image data (hereinafter, referred to as a second image data pixel area), an original accurate density cannot be expressed.

The image output unit 2 of the image forming apparatus of the present invention
In order to determine the object area density and the background area density in the second image data pixel area in a decoder 211 to be described later, the above problem is solved by generating each pixel density reference direction data. This configuration will be described later. (Image Forming Apparatus) FIG. 8 is a schematic view of the image output unit 2 of the image forming apparatus of the present invention. The image output unit 2 includes an image signal conversion unit 210, a laser driving device 220, and an image exposure unit 20.
0. The image data written in the buffer memory 140 of the image processing device 1 is read out in synchronization with a control signal transmitted from the image output unit 2 and input to the image signal conversion unit 210. The image signal converter 210 generates a laser modulation signal for driving the laser driver 220, and supplies the laser modulation signal to the image exposure unit 200.

As shown in FIG. 9, the image exposure unit 200
Photoconductor 201, laser diode 202, collimator lens 203, first cylinder lens 205, mirror 20
6, polygon mirror 207, f-θ lens 208, second
The laser diode 202 is driven by driving the laser driving device 220 with the cylinder member 209 as a constituent element, and the light beam modulated according to the image information is scanned on the photosensitive member 201 to form an image.

As shown in FIG. 10, a decoder 211 and a parallel-serial converter 21
2, image data selection processing section 260, screen generator 213, screen select generator 214,
A combiner 215 and the like are provided, and each processing unit includes a buffer, a delay circuit, a data latch, and the like (not shown) for synchronizing with a pixel clock (PCLK). The decoder 211 is provided with a pattern generation table 211a as shown in FIG.

The image data read from the image processing device 1 is input to the decoder 211 of the image signal conversion unit 210 and the image data selection processing unit 260. Note that the image data input to the decoder 211 and the image data selection processing unit 260 are two types of image data having different data structures (first image data and second image data shown in FIG. 6).
The processing is executed based on each image data.

For the image data input to the decoder 211, the value of the MSB in the image data is first determined. MS
When B is 0, that is, when the image data is the first image data, 0 data is output to the image data selection processing unit 260. MSB
Is 1, that is, in the case of the second image data,
As shown in (a), image data representing the pattern number is decoded from the pattern data (pattern number) included in the second image data, and a 16-bit bitmap of a pattern corresponding to the pattern number and a bitmap pattern A 3-bit flag (object density reference direction data) indicating the direction (pixel density reference direction) in which pixels of the first resolution near 8 that refer to the density in order to determine the density of the object area where is turned on A 3-bit flag (background density reference direction data) indicating the pixel density reference direction for determining the density of the background area in which the bitmap data is turned off is provided in the pattern generation table 211a provided in the decoder 211. Is read out. The reference directions indicated by the three-bit flags are eight directions when the upper side of the target pixel is north, east, west, north and south.

That is, the decoder 211 detects the bitmap pattern configuration of the pixel, and obtains the pixel density reference direction based on the pattern distribution such as the bias of the ON pixel. For example, if the ON pixels are unevenly distributed to the upper left, the upper left (northwest) is the pixel density reference direction for the object, and the lower right (southeast) is the pixel density reference direction for the background.

FIG. 11B shows an example in which the second image data including the pattern number "No. 6" is decoded. First, a 16-bit bitmap pattern corresponding to “No. 6” is output. In this bitmap pattern, the object area is unevenly distributed to the upper left. Therefore, for the object area, the upper left (northwest) is used as the pixel density reference direction, a 3-bit flag (object density reference direction data) indicating the upper left (northwest) direction is output, and the background is lower right (southeast). Is the pixel density reference direction, and a 3-bit flag (background density reference direction data) indicating the lower right (southeast) direction is
Output from the decoder 211. It is also possible to prepare a table indicating the pixel density reference direction corresponding to the pattern number in advance, and determine the pixel density reference direction using this table.

The decoder 211 performs a “rearrangement process” on the read bitmap, converts the read bitmap into a serial signal, and outputs the serial signal to the combiner 215. The determined pixel density reference direction is determined by the image data selection processing unit 2.
At 60, this is used to determine the pixel density of the object area and background area of the pixel developed at the second resolution.

First, regarding the read bitmap,
The “rearrangement process” that changes the arrangement of the pixels that are turned on in the divided area will be described. As shown in FIG. 12A, first, 16 pieces of the 96 dpm bitmap of the second resolution existing in the 24 dpm bitmap frame of the first resolution are divided into two, that is, the 96 dpm bitmap 8
The area is divided into a set of individual areas (area division), and then, in this area, rearrangement of eight bitmaps is performed in accordance with rules described later (rearrangement processing).

The right diagram in FIG. 12A shows a laser obtained by performing the above-described reordering process from the bit map shown in the left diagram in FIG. It is an exposure image.
On the other hand, the right diagram of FIG. 12B shows a laser exposure image obtained by directly performing parallel-serial conversion from the bit map shown in the left diagram of FIG. 12B.
As can be seen by comparing the two laser exposure images, if the parallel-serial conversion is performed after the rearrangement processing, a laser exposure image with sharp edges can be obtained.

Next, the sorting rules will be described. FIG. 13A shows a rule for rearranging data to be left-justified, which is set as a default when the number of pixels on the left and right is equal. The pixel of interest here is shown in FIG.
(A) is 8 pixels of 2 × 4 of 2 × 4 pixels surrounded by a thick line in the center of the 4 × 4 pixels shown in the left diagram of FIG. FIG. 13A shows a configuration in which the pattern is not deviated to the left or right in these eight pixels. In this case, as shown in the right diagram of FIG. In other words, the inside of the eight bitmap frames as shown in FIG. 13A is further divided into two parts on the left and right sides. When there is no deviation in both the left and right including the bitmap patterns, the pixels that are turned on are rearranged in ascending order from the area of the pixel number 1 shown in FIG.

As shown in the left diagram of FIG. 13B, when the number of pixels to be turned on in the eight bitmap frames of interest is biased to the right, the right diagram of FIG. As shown in FIG. 13, the pixels to be turned on are arranged in descending order from the area of the pixel number 8 shown in FIG.
Also, as shown in the left diagram of FIG. 13C, there is no bias in the eight central bitmap frames of interest,
When the pixels to be turned on including the bitmaps are biased to the right, as shown in the right diagram of FIG. 13C, the pixels are turned on in descending order from the area of the pixel number 8 shown in FIG. The pixels are arranged right-justified. Also,
As shown in the left diagram of FIG. 13E, in the case of a specific mode in which all the pixels of eight adjacent bitmaps are turned on, as shown in the right diagram of FIG. The data rearrangement for moving the ON pixels in parallel between the eight bitmaps is performed. In each case, the number of pixels that are turned on is the same as the original bitmap data.

As shown in FIG. 10, the bitmap pattern after the rearrangement process is output to the parallel-serial converter 212. Parallel-serial converter 212
Converts the 16-bit parallel signal output from the decoder 211 into a 1-bit serial signal and outputs the signal to the combiner 215. Parallel-serial converter 212
Represents the first to eighth pixels in the area surrounded by the thick line in the center of the bitmap pattern shown in the left diagram of FIG.
As shown in the right diagram of FIG. 14, they are arranged in series and output sequentially.

Next, a method for determining the pixel density of the object area and the density of the background area will be described.

The image data selection processing section 260 has a memory 261 and a controller 262, as shown in FIG. As shown in FIG. 10, the 12-bit image data read from the image processing apparatus 1 is input to the image data selection processing unit 260 and is temporarily stored in the memory 261. The pixel density reference direction data generated by the decoder 211 is input to the controller 262 of the image data selection processing unit 260. As shown in FIG. 11, the pixel density reference direction data is a 6-bit flag including a 3-bit flag representing object density reference direction data and a 3-bit flag representing background density reference direction data.

The image data selection processing unit 260 determines the reference direction based on the pixel density reference direction data input to the controller 262, and determines the first position located in the determined reference direction.
Using the density data included in the first image data of the pixel of the resolution, it functions as image density determining means for determining the density of the pixel of the second resolution. The first image data used for determining the density is the first image data of pixels in the vicinity of the pixel of interest 8 and the image density of the first image data is used as the pixel density of the second image data.

For example, 96 dp of a pixel of 24 dpm (first resolution) in the second column from the right in the second row from the top in FIG.
The bitmap pattern developed at m (second resolution) is composed of pixels in the object area eccentric to the lower right and pixels in the background area at the upper left.
Therefore, the pixel density reference direction of the object area is lower right (east-south), and the pixel density reference direction of the background area is upper left (northwest). There is a pixel of halftone density (75%) at the lower right of the target pixel, and the pixel density of the object area of the target pixel is determined using the density data included in the first image data of the lower right pixel. (75%). The halftone density (10
%), And the pixel density of the background area of the pixel of interest is determined as halftone density (10%) using the density data included in the first image data of the upper left pixel.

On the other hand, when the image data of the pixel located in the reference direction is not the first image data but the second image data having no density data, the pixel density is determined as follows.

If an error occurs in determining the pixel density of the background area, the pixel density of the background area is determined according to the flowchart shown in FIG. FIG. 16 shows a procedure for determining the pixel density of the background area, including the normal operation. First, a specified density value (0 or 255) is stored in the background area density buffer of the buffer memory 140.
Is set (step S21). Next, the pixel of interest is 0,
It is determined whether the pixel has a density value other than 255 (step S22). If the pixel is not a halftone pixel, it is determined whether the pixel located in the reference direction has density data (step S23). If the pixel located in the reference direction has the density data, the image density of the pixel is set in the background density buffer of the buffer memory 140 (step S27), and the halftone data representing the density value of the set pixel is set. Is output to the screen generator 213, and the screen selection signal is output to the screen select generator 214.
(Step S28). If the pixel located in the reference direction does not have density data, step S21
The specified density value set in the step is set as the density value of the pixel (step S
24), data representing the pixel density value is output to the screen generator 213, and a screen selection signal is output to the screen select generator 214 (step S).
28).

If the target pixel is a halftone pixel, it is not necessary to determine the background density. Next, it is determined whether the target pixel is a pixel having the above-mentioned edge flag (step S25), and the edge flag is set. If the pixel has the pixel, the density value of the pixel is set in the object density buffer of the buffer memory 140 (step S2).
6).

Finally, it is determined whether or not the pixel is at the rear end of the scan line (step S29). If it is the pixel at the rear end of the scanning line, the pixel density determining process ends. If it is not the pixel at the rear end of the scanning line, the process returns to step S22 to repeat the pixel density determining process.

If an error occurs in determining the pixel density of the object area, the pixel density of the object area is determined according to the flowchart shown in FIG. In the flow shown in FIG. 17, when the specified density value (0 or 255) is set in the object area density buffer of the buffer memory 140 in step S21, and the pixel located in the reference direction does not have density data in step S24. Except for setting the specified density value as the density value of the pixel object area and setting the image density value in the object area density buffer of the buffer memory 140 in step S27, the description is omitted because it is the same as the flow shown in FIG. .

As shown in FIG. 10 and FIG. 11, the image data selection processing unit 260 determines the density data (8 bits) of the object area and the background area determined according to the 6-bit flag indicating the pixel density reference direction. Density data (8 bits) as 16-bit halftone data
Output from the memory 261 to the screen generator 213. Also, as described later, the screen generator 21
Since there are a plurality of types of screen signals generated in step S3, the image data selection processing unit 260 uses the multiplexer 216 to select the output screen signal from the plurality of types of screen signals.
) Is determined for each of the object area and the background area, and 4-bit screen select data is output from the memory 261 to the screen select generator 214. The screen select data includes, for example, FL2 [1: 0] and FL3 [1:
0].

The screen generator 213 receives density data (8 bits × 2) for the second image data output from the image data selection processing section 260 and density data included in the first image data. An output timing corresponding to each pixel is set by a buffer circuit (not shown) or the like. For example, a plurality of screen signals corresponding to the density data are generated by the image signal control device illustrated in FIG.

The image signal control device shown in FIG. 19 will be briefly described. The image signal control unit includes a data latch 301, D
/ A converter 302, triangular wave generator 303, comparator 304
The data latch 301 receives image data and clock data for timing control. The clock data is supplied to the D / A converter 302 and the triangular wave generator 30.
3 is also output. The triangular wave generator 303 generates a triangular wave having a predetermined shape and outputs the generated triangular wave to the comparator 304. The image data output to the D / A converter 302 via the data latch is also D / A converted, output to the comparator 304, and compared with the triangular wave generated by the triangular wave generator 303. The screen signal is obtained and the combiner 21
5 is output. Output timing of each screen signal,
The comparison timing is controlled by a clock.

Screen select generator 214
Generates a plurality of screen signals output from the screen generator 213 and a selection signal for selecting pattern data converted into a serial signal by the parallel-serial converter 212, and outputs the selection signal to the combiner 215 or the multiplexer 216. I do.

As shown in FIG. 18, the combiner 215 includes inverters IN1 to IN4 and AND circuits AND1 to AND1.
The output terminal of each of the OR circuits is connected to the multiplexer 216. The logic circuit includes an AND8 and OR circuits OR1 and OR2. The logic circuit of the combiner 215 receives a serial signal (Serial Data) from the parallel-serial converter 212 and
A plurality of types of screen signals (four types of screen signals 1 to 4 in FIG. 18) are input from the screen generator 213 in accordance with the density information, and a screen selection signal (Screen select) is input from the screen select generator 214. You. The combiner 215 combines these signals while synchronizing them for each corresponding pixel.

That is, the serial signal input from the parallel-serial converter 212 is obtained by rearranging the 96-dpm high-resolution bitmap pattern by the decoder 211 as described with reference to FIGS. This is a serialized signal, which is an image signal processed as a laser exposure image by parallel-to-serial conversion as described in FIG. 14, but does not have density information of object area pixels and density information of background area pixels. is there. The density information is added to the serial signal by the screen signal and the screen selection signal input to the combiner 215. That is, the combiner 215 selects screen signals corresponding to a plurality of different density regions constituting the bitmap pattern developed at the second resolution, synthesizes the serial signal and the selected screen signal, and generates a 256-level signal. A modulated signal having a resolution of 96 dpm is generated. Note that a screen signal for determining the density of the pixel of the first resolution is generated by the screen generator 213 based on the density data of the first image data, and is input to the combiner 215 to synthesize data of 256 gradations. .

The modulated signal generated by the combiner 215 and having 256 gradations and a resolution of 96 dpm is input to the multiplexer 216, and a screen according to the configuration of the image data is selected according to the selection signal output from the screen select generator 214. , Laser driving device 22
Output to 0.

For example, a screen signal 1 based on the density of the object area of the first image data obtained for a certain pixel of the graphic data is a screen signal 1, a screen signal based on the density of the background area is a screen signal 4, and a second screen signal. A screen signal based on the density of the object area of the image data is defined as a screen signal 1, and a screen signal based on the density of the background area is defined as a screen signal 4. A screen signal based on the density of the object area of the first image data obtained for a pixel different from the pixel area is defined as a screen signal 2, a screen signal based on the density of the background area is defined as a screen signal 3, and the second image data is generated. Let the screen signal based on the density of the object area be the screen signal 2 and the screen signal based on the density of the background area be the screen signal 3, the screen signals (screen signal 1 to screen signal 4) corresponding to each pixel are associated. The selected signal is combined by the combiner 215 with the serial signal, and is output as a laser modulation signal to the laser driving device 220 via the multiplexer 216, and is supplied to the image exposure unit 200. Note that each screen signal may be the same output signal.

Hereinafter, the output result of the image forming apparatus of the present embodiment will be described in comparison with the output result of the conventional image forming apparatus. FIG. 20 is a schematic diagram of an image when a graphic alias is drawn by the image forming apparatus of the present embodiment and the conventional method. FIG. 20A shows the PDL
20 (b) is an image processed and output by the image forming apparatus of the present embodiment, FIG. 20 (c).
Is an image that has been rendered and output by the conventional method.

As shown in FIG. 20A, the original image has a density of 10%.
It is composed of an object area having a density of 0% and a background area having a density of 10%, and the contour is composed of a smooth curve. In FIG.
In the contour part processing, in order to faithfully represent the contour curve, the contour part has a higher resolution (96
dpm) is compared with a conventional image processing system.

In the conventional image processing system, the contour portion has a higher resolution (96 dpm) than a region (24 dpm) other than the contour region.
pm). At this time, since the processing depends only on the density information (100% density) of the object area,
The density of the background area in the pixel developed at high resolution is output as a density of 0%, and as shown in FIG. 20C, matching with the density of the other 24 dpm background area (density of 10%) is performed. The result is that it cannot be taken.
In other words, in the conventional example of a method in which an alias is developed to a high resolution of 96 dpm and switching is performed between a 24 dpm pixel and a 96 dpm pixel, as shown in FIG.
When a pixel is switched, a white defect occurs in the alias.

On the other hand, in the image forming apparatus of the present embodiment, a high resolution (96 dpm)
At the time of processing, the density information (density 100
%) And background area density information (density 10
%) And generate a high-resolution image. Therefore, FIG.
As shown in FIG. 2B, the same density output as that of the other low-resolution (24 dpm) region is obtained for both the density of the object area and the density of the background area in the pixel developed at the high resolution.

As described with reference to FIG. 11, when the high-resolution bitmap pattern is generated in the decoding process of the decoder 211, the density reference direction and the background area of the object area in the pixel expanded at high resolution are generated. Is generated in such a manner that the information in the density reference direction is generated and the respective densities are determined with reference to the density of the pixels located in these density reference directions.

FIG. 21 shows a graphic alias,
FIG. 9 shows still another example of the image forming apparatus of the present embodiment and a schematic view of an image when drawing by a conventional method. FIG.
(A) is an original picture represented in PDL, FIG. 21 (b)
Is an image processed and output by the image forming apparatus of the present embodiment, and FIG. 21C is an image output by performing a drawing process in a conventional method.

In the example of the conventional method shown in FIG. 21C, the density information in the background area is prioritized, so that the contour area cannot be extracted and subjected to high-resolution processing. Low resolution (24dp
m) is performed, and a faithful contour cannot be expressed. That is, in the conventional example of FIG.
Although no defect occurs as in (c), anti-aliasing is not performed, so that jaggies depending on the resolution are conspicuous and the shape of the original image shown in FIG. 21A is considerably different.

On the other hand, the image forming apparatus of the present embodiment processes the contour at a higher resolution (96 dpm) than the area other than the contour area (24 dpm). Area density information (density 7
5%) and background area density information (density 1
0%) and generate a high-resolution image. Therefore,
As shown in FIG. 21B, the same density output as that of the other low-resolution (24 dpm) areas is obtained for both the density of the object area and the density of the background area in the pixels developed at high resolution.

As described above, in the image forming apparatus of the present embodiment, since the alias of the contour expression also has 256 gradations, it is drawn without any inferiority to the area other than the alias, and is very similar to the original image represented in the PDL. Is obtained.

As described above, the image processing apparatus and the image forming apparatus according to the present embodiment can output image data at a plurality of different resolutions, and can process aliases of characters and graphics with high resolution. Since the 256 gradations can be maintained in the same manner as the low-resolution part other than the alias, even when the background color and the alias such as characters overlap, it is faithful to the original image represented in the PDL. The effect is that gradation can be expressed and a high-quality image can be output.

In the present embodiment described above, an example has been described in which the conversion processing unit 127b first performs a conversion process to a bitmap according to the flowchart shown in FIG. 4 and then performs the conversion process. The conversion processing can also be performed according to the following procedure according to the flowchart shown in FIG. 22 by replacing the 2 expanding means 127b1 with straight-line fitting means.

Input image information such as fan-shaped graphic data described in PDL (see FIG. 7A)
3, the bit conversion frame of the second resolution (high resolution) is generated in the resolution conversion unit 126 of the image development unit 123, and the coordinate axes are determined (FIG. 22: step S31). Note that the bitmap frame of the second resolution may be generated within a range where objects such as characters and figures exist, or may be generated over the entire screen.
It must be synchronized with the bitmap frame of the first resolution used by the first expansion processing unit 127a.

Next, in the straight line fitting means, the outline (outline) of the figure represented by a cubic Bezier curve or the like is used.
Is drawn (FIG. 22: step S32). Next, the contour is approximated by a known straight-line approximation method (for example, a method of repeating a process of generating a new control point at an intermediate point between the control points to perform a straight-line approximation) and the like, and an approximate straight line is drawn (FIG. 22: Step S33).

Next, a look-up table (128 in FIG. 24) indicating the line number corresponding to the line segment information which is the segment information between the contour line and the pixel grid having the basic resolution of 24 dpm.
Based on a), a "straight line fitting" process of converting the graphic data into a standardized approximate line or a combination of approximate lines is performed (step S34). For example, a line with a line number from 0 to 18 shown in FIG.
Nine types of contour lines can be represented.

FIG. 23B shows a bit map pattern corresponding to the line numbers from 0 to 18 in FIG. 23A. Using a look-up table (128b in FIG. 24) indicating a bitmap pattern corresponding to such a line number, 96 dp in units of 24 dpm
A bitmap having a resolution of m can be generated. When there are a plurality of contour lines in a 24 dpm grid or when there is an inflection point, a corresponding bitmap pattern can be obtained by combining a plurality of line numbers. Further, a lookup table (FIG. 24) in which pattern numbers are assigned to these bitmap patterns.
128c) can be prepared, and the bitmap can be converted to a pattern number.

Therefore, 256 kinds of bitmap patterns obtained by the straight line fitting are determined, and a look-up table (128d in FIG. 24) indicating the pattern numbers corresponding to the line numbers is prepared. If a pattern number is selected according to the combination of numbers, pattern data can be generated in the same manner as described above without expanding input image information into a bitmap (FIG. 4: step S35).

Further, in the present embodiment, an example has been described in which the data width of the density data and the data width of the pattern data are the same. However, the data width of the pattern data is made smaller than the data width of the A check bit or the like may be added to these bits to make the same width as a whole.

[0104]

According to the image processing apparatus and the image forming apparatus of the present invention, the data width of the image data expanded at a plurality of resolutions is made the same, so that the image data can be easily handled.
This has the effect.

Further, the image processing apparatus and the image forming apparatus of the present invention have an effect that no defect occurs even if the development resolution of characters, line drawings, graphics, etc. on the background color is increased.

Further, the image processing apparatus and the image forming apparatus of the present invention do not need to output image data a plurality of times for different resolutions, and can form an image without impairing the recording speed or image quality. It works.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram illustrating an embodiment of an image processing apparatus and an image forming apparatus according to the present invention.

FIG. 2 is a functional block diagram illustrating an outline of an operation of a main control unit.

FIG. 3 is a functional block diagram illustrating an outline of an operation of an image developing unit.

FIG. 4 is a flowchart illustrating a procedure of an expansion process and a conversion process of a conversion processing unit.

FIG. 5 is a diagram showing a bitmap pattern stored in a lookup table and a part of a pattern number given to the bitmap pattern.

FIG. 6 is a configuration diagram of image data generated by an information combining unit.

FIG. 7 is a schematic diagram showing an output image based on an original image described in PDL and data before and after information is combined by an information combining unit.

FIG. 8 is a schematic configuration diagram of an image output unit of the image forming apparatus according to the present embodiment.

FIG. 9 is a schematic diagram of an image exposure unit in the image output unit.

FIG. 10 is a block diagram illustrating a schematic configuration of an image signal conversion unit.

FIG. 11 is an explanatory diagram for describing an outline of an operation of the decoder.

FIG. 12 is an explanatory diagram for describing an outline of an operation of the decoder.

FIG. 13 is an explanatory diagram for explaining a sorting rule.

FIG. 14 is a schematic diagram illustrating a conversion method of a parallel-serial converter.

FIG. 15 is a block diagram illustrating a schematic configuration of an image data selection processing unit.

FIG. 16 is a flowchart illustrating a procedure for determining the density of a pixel of the second resolution when a pixel in the reference direction does not have density data.

FIG. 17 is a flowchart illustrating a procedure for determining the density of a pixel of the second resolution when the pixel in the reference direction has no density data.

FIG. 18 is a circuit diagram illustrating a configuration of a logic circuit of a combiner in the image signal conversion unit.

FIG. 19 is a schematic configuration diagram of an image signal control unit.

FIG. 20 is a diagram schematically illustrating an original image described in PDL, and an image image drawn by the image forming apparatus of the present embodiment and the conventional image forming apparatus.

FIG. 21 is a diagram schematically illustrating an original image described in PDL, and an image image when drawn by the image forming apparatus of the present embodiment and the conventional image forming apparatus.

FIG. 22 is a flowchart illustrating a procedure of a conversion process when the conversion process is performed without performing the expansion process.

FIG. 23 is a diagram illustrating a configuration example of an area pattern represented by a line number and a line number.

FIG. 24 is a schematic diagram of a group of tables provided in an image developing unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image processing apparatus 2 Image output part 110 Communication control part 120 Main control part 121 Communication protocol analysis / control part 122 PDL command / data analysis part 122b Threshold table 123 Image development part 124 Information connection part 125 Color judgment / operator provision part 126 Resolution conversion unit 127a First expansion processing unit 127b Conversion processing unit 127b1 Second expansion unit 127b Conversion unit 128 Table group 129 Font cache 127c, 127d Flag addition unit 130 Magnetic disk device 140 Buffer memory 150 Output unit control unit 200 Image exposure unit 211 Decoder 212 Parallel-serial converter 213 Screen generator 214 Screen selector generator 215 Combiner 216 Multiplexer 220 Laser driver 260 Image data -Option processing unit 261 memory 262 controller

Continued on the front page F term (reference) 2C087 AA16 AB05 BC05 BC14 BD13 CA02 5C053 FA04 FA23 GB40 JA16 KA01 KA21 LA11 LA14 5C076 AA21 AA32 BB05 5C077 LL05 LL09 LL17 MP06 MP07 MP08 NN05 PP15 PP20 PP27 PP28 PP33 PP38 PP43 PP38 PP43 PP38 PP38 PP33 PP58 TT02 9A001 HH24

Claims (11)

[Claims] 1. An image processing apparatus for converting input image information into image data in a form used for image formation in an image forming apparatus, wherein the input image information is expanded into first expanded data in a pixel unit of a first resolution. A first developing means for converting input image information into a pattern in which pixel-based data of a second resolution higher than the first resolution is arranged;
A conversion processing unit that converts the pattern data into pattern data corresponding to an array pattern representing an area of a pixel unit of resolution and having a data width within a data width of density data representing the density of the first expanded data; And an identification code adding means for adding an identification code indicating whether the data includes data or not. 2. The image processing apparatus according to claim 1, wherein the conversion processing unit expands the input image information into second expansion data of a second resolution pixel unit, and the second expansion unit representing an area of the first resolution pixel unit. 2. The image processing apparatus according to claim 1, further comprising: a conversion unit configured to convert an array pattern of the development data into pattern data whose data width is within the data width of the density data representing the density of the first development data. 3. The image processing apparatus according to claim 2, wherein the conversion unit performs conversion using a look-up table indicating a pattern number assigned to the array pattern of the second expanded data. 4. Converting the first expanded data into first image data including density data for each color based on color information included in input image information, and converting the first resolution pixel unit area into pixels. 3. An information combining means for converting data representing a pixel-unit area of the first resolution, in which all the second developed data are the same, into the first image data when all the second developed data are the same. Or the image processing apparatus according to 3. 5. A second image including the first image data obtained from the first expanded data and the pattern data transmitted from the image processing apparatus according to claim 1. Description:
An image forming apparatus capable of outputting at a plurality of resolutions based on two types of image data, wherein the second image data is selected based on an identification code and included in the selected second image data. And converts the pattern data to be converted into an array pattern of data in pixel units of the second resolution, and generates pixel density reference direction data for obtaining density data of pixels of the second resolution constituting the array pattern obtained by the conversion. Based on the density data of the pixels located in the reference direction indicated by the pixel density reference direction data.
An image forming apparatus comprising: a density determining unit that determines the density of a pixel having a resolution. 6. If the density determining means does not have density data of a pixel located in the reference direction indicated by the pixel density reference direction data, the density determining means changes the array pattern based on the density data of a pixel different from the reference direction. The image forming apparatus according to claim 5, wherein the density of the second resolution pixels is determined. 7. A screen signal generating means for generating a plurality of screen signals according to density data of a pixel having a second resolution determined by said density determining means; a screen signal generated by said screen signal generating means; 7. The image forming apparatus according to claim 5, further comprising: synthesizing means for synthesizing a serial signal obtained by performing parallel-serial processing on an array pattern of data in pixel units of the second resolution to generate a modulation signal. apparatus. 8. A selecting means for selecting and outputting, from a plurality of screen signals, a screen signal corresponding to density data of pixels of a second resolution constituting an array pattern, the density data being determined by the density determining means. Claim 7 having
An image forming apparatus according to claim 1. 9. The synthesizing unit corresponds to a screen signal corresponding to the density data included in the first image data and the density data determined by the density determining unit for the pixels of the second resolution forming an array pattern. The image forming apparatus according to claim 7, wherein the image forming apparatus and the screen signal are combined and output. 10. The image forming apparatus according to claim 7, wherein the synthesizing unit includes a logical operation element. 11. The pixel density reference direction data generated by the decoder is determined based on a pattern distribution of an array pattern of pixel-based data of a second resolution obtained from pattern data included in the second image data. The image forming apparatus according to claim 5.