JP2004202944A - Printing equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide printing equipment, in which gradation is represented by screen processing, especially a screen (a filter) is selected based on the information of printing data in a unit area so as to prevent jitters or streaks from developing and execute a printing processing substantially coinciding with the attributes of drawing objects. <P>SOLUTION: A printing data drawing part 4 analyzes printing data fed from a host device 2 and expands to an image memory 6 as drawing data. This expansion processing is executed based on a filter having a screen ruling registered in a screen pattern data expansion buffer 5. The filter having the screen ruling executes, for example, by comparing data size per unit area of the printing data with information registered in advance in a drawing object size table 11 and by comparing not only the difference in the drawing object but also substantially the printing size with reference values so as to execute a printing processing, in which jitters and streaks are prevented from developing. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a printing device that expresses gradation by screen processing.
[0002]
[Prior art]
2. Description of the Related Art A color printing apparatus uses a plurality of color toners such as yellow (Y), magenta (M), and cyan (C), and expresses density (gradation) by performing area gradation of each color. In addition, in order to perform area gradation at high speed, a dither pattern having a predetermined size and a position where printing is performed for each density is prepared, and the pattern is applied to each pixel and connected to each other to achieve high speed. Realizes color printing.
[0003]
The dither pattern needs to be adapted to the characteristics of the hardware that uses it, and there are various modes. 2. Description of the Related Art Conventionally, in print processing in an OS (operation system) environment, color printing is performed by selectively using dither patterns used for each of three objects of characters (text), graphics (graphics), and photographic images.
[0004]
In such a color printing apparatus, so-called screen processing is performed on input print data to perform gradation expression. Then, a plurality of filters (dither patterns) having different numbers of lines are used while being switched. For example, a screen (dither pattern) having a high number of lines (fine) is used for character data having a small size, and a line number is used for graphic data having a large coloring area or image data such as a photographic image. The printing process is performed using a low (rough) screen. That is, the filter is determined according to the attributes of the drawing object, and the printing process is performed.
[0005]
The reason is that a filter having a large number of lines has horizontal streaks (jitter) due to uneven conveyance of the paper and vertical streaks (streaks) due to uneven light amount of the head, as compared with a filter having a small number of lines. The color uniformity of the whole printed matter is poor, but the expressiveness of fine parts is excellent. On the other hand, a filter with a small number of lines is inferior to a filter with a large number of lines in terms of expressiveness of a fine portion, but is resistant to the above-mentioned jitter and streaks, and is excellent in color uniformity of the entire printed matter. It is.
[0006]
Patent Document 1 discloses an invention in which a screen pattern is changed in accordance with an image enlargement / reduction instruction, and the present invention discloses a method of selecting a screen pattern from a plurality of screen patterns prepared in advance according to an image enlargement / reduction instruction. The printing process is performed by selecting an optimal screen according to the magnification.
[0007]
[Patent Document 1] JP-A-11-220613
[0008]
[Problems to be solved by the invention]
However, in the conventional method of determining the screen ruling (the method of determining the filter), as described above, the screen ruling is determined based on the attribute of the drawing object. Therefore, in the case of unexpected data, the drawback of the used screen is emphasized.
[0009]
For example, when the print data to be actually processed is character data having a large size, the attribute of the drawing object is “character data”. Therefore, a filter having a large number of lines is used, and the jitter and the streak become conspicuous. . On the other hand, even if the print data to be actually processed is graphic data with a small coloring area or image data representing a fine portion, the drawing object attribute is “graphic data” or “image data”, and the screen with a low number of lines is used. Is selected, and the expression of fine details is reduced.
[0010]
Therefore, the present invention selects a screen (filter) based on information of print data within a unit area, prevents the occurrence of jitter and streak, and performs a printing process that substantially matches the attribute of a drawing object. To provide a printing apparatus for performing the printing.
[0011]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided a printing apparatus which includes a plurality of screens having different numbers of lines, uses the screens while switching the screens, and performs a printing process based on the drawing data. A means for recognizing the object on a per-object basis, a means for calculating the print size of the recognized drawing object, a means for selecting one of the plurality of screens having different numbers of lines based on the calculated print size, Means for using the selected screen and generating the drawing data based on the recognized drawing object using the selected screen.
[0012]
With this configuration, it is possible to prevent the occurrence of jitter and streaks, and to perform a printing process that substantially matches the attribute of the drawing object.
According to a second aspect of the present invention, there is provided a printing apparatus which includes a plurality of screens having different numbers of lines, uses the screens while switching the screens, and performs a printing process based on drawing data. Means for dividing the print data per unit area, means for calculating the degree of color variation from the divided print data per unit area, and selecting one of the plurality of screens having different numbers of lines according to the degree of color variation. This can be attained by providing a printing apparatus having means for generating drawing data using the selected screen based on the divided print data per unit area.
[0013]
With this configuration, it is possible to prevent the occurrence of jitters and streaks, and to perform a printing process that substantially matches the attributes of the drawing object.
According to a third aspect, in the first aspect, the drawing object is, for example, character data, graphic data, or photographic image data.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<First embodiment>
FIG. 1 is a system configuration diagram of a printing apparatus used in the present embodiment. In FIG. 1, a print data receiving unit 1 analyzes print data transmitted from a host device 2 such as a personal computer (PC) and holds one page of print data in a print data holding buffer 3. Further, when the holding of the print data for one page is completed, the print data receiving unit 1 notifies the print data drawing unit 4 of the completion of holding the print data.
[0015]
When receiving the notification of the completion of the holding of the print data from the print data receiving unit 1, the print data drawing unit 4 sequentially analyzes the held print data. Further, at the time of this analysis processing, for each drawing object, the drawing processing to the image memory 6 is performed using the screen pattern developed in the screen pattern data development buffer 5 described later. When the printing of all the print data for one page is completed, the print data drawing unit 4 notifies the drawing data transfer unit 7 of the completion of the drawing process.
[0016]
Further, the screen pattern selection and development unit 8 reads a corresponding screen (filter) from the screen pattern data storage unit 10 based on the size information recognized by the drawing object size recognition unit 9 and registers the screen (filter) in the screen pattern data development buffer 5. .
[0017]
The drawing object size recognition unit 9 has a function of reading out corresponding size information from the information on the unit area of the print data, and recognizes the corresponding size information with reference to the drawing object size table 11.
FIG. 2 is a diagram showing an example of a data configuration registered in the drawing object size table 11. Size information is registered along with the record number. The drawing object size recognition unit 9 refers to the drawing object size table 11 using print data per unit area, and reads out corresponding size information.
[0018]
Note that the printer engine 12 shown in FIG. 1 has a function of performing printing processing on paper using drawing data sequentially read from the image memory 6 by the processing of the drawing data transfer unit 7, and includes a print head and the like. Have been.
Hereinafter, the processing of this example will be specifically described.
[0019]
The host device 2 sends the print data created according to the application program to the printing device, and the print data receiving unit 1 performs print data holding processing according to the flowchart shown in FIG. That is, it is determined whether print data has been received from the host device 2 (step (hereinafter, referred to as S) 1), and when print data is received (S1 is YES), the print data is sequentially written into the print data holding buffer 3 ( S3). Thereafter, it is determined whether the holding of the print data for one page is completed (S3). When the holding of the print data for one page is completed (YES in S3), the print data holding unit 3 instructs the print data drawing unit 4 to store the print data in the print data holding buffer 3. Is notified that print data for one page is held (S4).
[0020]
Upon receiving this notification, the print data drawing unit 4 performs processing according to the flowchart shown in FIG. That is, when there is a notification of the completion of the holding of the print data, this notification is determined (S5: YES), one unit of the drawing object which has not been drawn is recognized (S6), and the attribute of the drawing object is displayed on the screen. The pattern selection and development unit 8 is notified (S7).
[0021]
The screen pattern selection / deployment unit 8 performs processing according to the flowchart shown in FIG. 5, and upon receiving the above notification from the print data rendering unit 4 (S8), further informs the drawing object size recognition unit 9 of information regarding the print size (S9). ). The information on the print size is information on print data (print density) included per unit, and the information is transmitted to the drawing object size recognition unit 9.
[0022]
The drawing object size recognizing unit 9 determines whether the information has been supplied from the screen pattern selection and development unit 8 (S10). When the information is supplied (S10: YES), a print size calculation process is performed (S11). . In this process, for example, when the density is high, the print data amount is large, and when the density is low, the print data amount is small.
[0023]
Next, the drawing object size recognition unit 9 refers to the drawing object size table 11 and compares the calculation result with the information on the print size (S12). Here, if the print size is larger (S13: YES), a selection of a screen pattern with a lower number of lines is notified (S14). On the other hand, if the print size is smaller (NO in S13), the selection of the screen pattern with a higher number of lines is notified (S15).
[0024]
For example, the print size stored in the drawing object size table 11 (hereinafter, referred to as “print size in table”) will be specifically described as 0.25 square inches shown in FIG. 2 described above. First, when the drawing object is character data of 24 points 5 CPI (Character Per Inch), the print size of this drawing object is 24/72 inches high x 1/5 inch wide = 0.07 square inches. The print size is 0.25 square inches or less. Therefore, in this case, the drawing object size recognizing unit 9 notifies the screen pattern selecting / developing unit 8 of selection of a screen having a high number of lines.
[0025]
On the other hand, if the drawing object is short graphic data having a height of 20 mm and a width of 30 mm, the print size of this drawing object is 20 / 25.4 inches in height × 30 / 25.4 inches in width = 0.93 square inches. Exceeds the "print size" of 0.25 square inches. Therefore, in this case, the drawing object size recognizing unit 9 notifies the screen pattern selecting / developing unit 8 of selection of a screen having a low frequency.
[0026]
Further, when the drawing object is a height of 80 pixels and a width of 120 pixels, the print size of the drawing object is 80/72 inches in height × 120/72 inches in width = 1.85 square inches, which is 0.25 of “print size in table”. More than a square inch. For this reason, the drawing object size recognizing unit 9 notifies the screen pattern selecting and developing unit 8 of selection of a screen having a low number of lines.
[0027]
Upon receiving the screen (filter) selection information (YES in S16 (see FIG. 5)), the screen pattern selection and development unit 8 selects a corresponding screen (filter) from the screen pattern data storage unit 10 based on the information. Then, it is registered in the screen pattern data development buffer 5 (S17). Then, the screen pattern selection and development unit 8 notifies the print data drawing unit 4 of the completion of the development of the screen pattern data (S18).
[0028]
When confirming the above notification (YES in S19 (see FIG. 4)), the print data drawing unit 4 develops the print data in the image memory 6 based on the screen pattern developed in the screen pattern data development buffer 5 (S20). ).
Thereafter, it is determined whether there is an unimaged drawing object (S21). If there is an unimaged drawing object (S21: NO), the above processing is repeated to develop the drawing data in the image memory 6. Then, when all the non-image drawing objects are processed (S21: YES), the drawing data transfer unit 7 is notified that the drawing processing of the print data is completed (S22).
[0029]
The drawing data transfer unit 7 determines the notification in accordance with the flowchart shown in FIG. 7 (S23), and upon receiving the notification (S23: YES), reads the drawing data from the image memory 6 and transfers it to the printer engine 12 (S23). S24). Thereafter, the above processing is repeated, and the printing processing of the drawing data developed in the image memory 6 is sequentially performed.
[0030]
As described above, according to the present embodiment, the screen ruling is changed according to the print size of each drawing object, and the screen (filter) having the optimal ruling is automatically selected to perform the printing process. Therefore, optimal printing processing can be performed without generating streaks or jitter.
[0031]
In the above-described embodiment, the screen pattern selection processing is performed on the printer device side. However, a configuration in which the screen pattern is selected by the printer driver and the information is transferred to the printing device may be adopted.
Further, the present invention is not limited to a screen having a high screen ruling and a screen having a low screen ruling. The screen may be further added to select a screen having three or more screens.
[0032]
Further, in the above embodiment, the level of the number of lines of the screen pattern is determined only by the print size, but the shape of the drawing object may be added. For example, even if the calculated print size exceeds the “print size in table”, such as a rectangle (2 mm × 200 mm) having an extremely short short side, a screen with a high line count may be selected. .
<Second embodiment>
Next, a second embodiment of the present invention will be described.
[0033]
FIG. 8 is a system configuration diagram illustrating the printing apparatus of the present embodiment. In the drawing, a configuration different from that of the above-described embodiment is such that a unit area drawing data buffer 13 is provided in place of the drawing object size recognition unit 9 and a reference difference value table 14 is provided in place of the drawing object size table 11. , And a unit area drawing data buffer 15 is further provided. Other configurations, for example, the configuration of the print data receiving unit 1, the print data holding buffer 3, the print data drawing unit 4, the drawing data transfer unit 7, and the like are the same as those of the above-described embodiment.
[0034]
As described above, first, the print data receiving unit 1 holds the print data supplied from the host device 2 in the print data holding buffer 3 for one page. The print data drawing unit 4 sequentially reads out the print data held in the print data holding buffer 3, performs an analysis process, and develops the print data in the image memory 6.
[0035]
Thereafter, the print data drawing unit 4 performs a print process according to the flowchart shown in FIG. 10, and first determines whether there is a print data holding completion notification (step (hereinafter, referred to as ST) 1). Then, when there is a print data holding completion notification (ST1 is YES), undrawn print data is written into the unit area drawing data buffer 15 for each unit area (ST2). Then, the writing of the unit area drawing data is notified to the screen pattern selection and development section 8 (ST3). Thereafter, it waits for a screen pattern data developing completion notification from the screen pattern selecting and developing unit 8 (ST4).
[0036]
The screen pattern selection / deployment unit 8 performs processing according to the flowchart shown in FIG. 11, and upon receiving the above notification from the print data drawing unit 4 (ST5: YES), notifies the writing of unit area drawing data (ST6). This notification of writing the unit area drawing data is transmitted to the unit area drawing data buffer 13.
[0037]
The unit area drawing data buffer 13 performs processing according to the flowchart shown in FIG. 12, and first determines whether or not the notification has been transmitted from the screen pattern selection / deployment unit 8 (ST7). A difference value is calculated (ST8). Then, a comparison is made with the reference difference value registered in the reference difference value table 14 (ST9). As a result, when the maximum difference value is larger than the reference difference value (ST10: YES), it is determined that the variation of the unit area drawing data is large, and a selection of a screen pattern having a large number of lines is notified (ST11). On the other hand, when the maximum difference value is smaller than the reference difference value (NO in ST10), it is determined that the unit area drawing data has a small variation in color, and a selection of a screen pattern with a low number of lines is notified (ST12).
[0038]
For example, if the unit area drawing data is CMYK square 8-bit image data of 128 pixels × 128 pixels, 16384 pixels 128 × 128) are analyzed, the maximum value and the minimum value are calculated for each CMYK, and the CMYK is further calculated. Each time, the minimum value is subtracted from the maximum value to calculate a difference value. Then, the largest difference value among the CMYK difference values is set as the maximum difference value. For example, in the example shown in FIG. 13, the difference value 24 of M is the maximum difference value. In the example shown in FIG. 14, the Y difference value 17 is the maximum difference value.
[0039]
Here, if the reference difference value stored in the reference difference value table 14 is 20, the maximum difference value 24 exceeds the reference difference value 20, so that the unit area drawing data analysis unit 13 uses the screen pattern selection and development unit. 8 is notified of the selection of a screen with a high number of lines. On the other hand, in the example shown in FIG. 14, the difference value 17 of Y is the maximum difference value, the reference difference value stored in the reference difference value table 14 is 20, and the maximum difference value 17 is the reference difference value. Since it is 20 or less, the unit area drawing data analysis unit 13 notifies the screen pattern selection and development unit 8 of selection of a screen having a low line number.
[0040]
Upon receiving the screen selection information (YES in ST13 (see FIG. 13)), the screen pattern selection / deployment unit 8 selects a corresponding screen from the screen pattern data storage unit 10 based on the information, and The data is developed in the data development buffer 5 (ST14). Then, the completion of the development of the screen pattern data is notified to the print data drawing unit 4 (ST15).
[0041]
When confirming the above notification (YES in ST4), the print data drawing section 4 uses the screen pattern developed in the screen pattern data development buffer 5 to store the print data in the image memory 6 based on the unit area rendering data table. Expand (ST16).
[0042]
Thereafter, it is determined whether or not there is undrawn print data (ST17). If there is undrawn print data (ST17: YES), the above processing is repeated to sequentially develop the drawn data in the image memory 6. When all of the undrawn print data is processed (YES in ST17), the drawing data transfer unit 7 is notified that the drawing processing of the print data is completed (ST18).
[0043]
The drawing data transfer unit 7 determines the above notification according to the flowchart shown in FIG. 7 described above, reads out the drawing data from the image memory 6, transfers the drawing data to the printer engine 12, and performs a printing process on paper.
As described above, according to the present embodiment, the screen ruling can be automatically changed according to the degree of color variation of the data drawn for each unit area. Automatically, regardless of the drawing object, only the advantages of screens with different numbers of lines are reflected, and a high quality printed matter can be obtained.
[0044]
Note that, in the present embodiment, as in the first embodiment, the screen pattern may be selected by a printer driver, and the information may be transferred to a printing apparatus. Further, the present invention is not limited to a screen having a high screen ruling and a screen having a low screen ruling. The screen may be further added to select a screen having three or more screens.
[0045]
Furthermore, in the description of the second embodiment, the level of the number of lines of the screen pattern is determined based on the maximum difference value. However, for example, a histogram is calculated for the unit area drawing data, and the standard deviation is referred to. A configuration in which the degree of color variation is determined by statistical processing may be adopted.
[0046]
Further, the drawing data is developed in the image memory 6 for each unit area (for example, 128 pixels × 128 pixels), but may be configured to be developed for each pixel. In this case, the data to be written in the unit area drawing data buffer 15 is Alternatively, data of a unit area (for example, 127 pixels × 127 pixels) around the pixel may be used.
<Third embodiment>
Next, a third embodiment of the present invention will be described.
[0047]
FIG. 15 is a configuration diagram of a printing system including the printing apparatus of the present embodiment. In FIG. 1, an operating system (OS) 21, a printing application 22, and a printer driver 23 are built in a personal computer (PC) 20, and are connected to a printer device (printing device) 24.
[0048]
The print data created based on the application 22 is sent to the printer driver 23 through the operating system 21, and the printer driver 23 converts the print data into an intermediate code in a command format.
Here, FIG. 16 shows a dialog for setting conditions at the time of conversion processing by the printer driver 23. There are settings to select dithering for text, graphics, and images respectively. Hereinafter, description will be given according to the flowchart shown in FIG.
[0049]
First, the print data created by the application 22 is sent to the printer driver 23 through the operating system 21 as described above. The printer driver 23 first determines the drawing attribute (step (hereinafter, referred to as STP) 1). That is, the input print data is classified into three attributes: text, graphic, and image (photo). Note that image data is not subject to dither “automatic” in this embodiment.
[0050]
On the other hand, for graphic data, it is first determined whether the dithering setting shown in FIG. 16 is "automatic" (STP2). Here, if it is not “automatic”, a designated dithering process is performed similarly to the image (STP3). On the other hand, if "automatic" is set, the size is determined next (STP4). In the case of text data, the same processing as in the case of graphic data is performed (STP2, STP4).
[0051]
Next, the size can be determined in various ways and distinctions, and is determined in consideration of the characteristics of the printer hardware, the processing capability of the software, and the like. For example, characters are determined simply by character size (expressed in points). In this case, when the character is smaller than the preset point, the dither pattern “resolution priority” suitable for expressing the small character is selected (STP5). On the other hand, when the character is larger than a preset point, a dither pattern “gradation priority” suitable for expressing gradation and a large area with a stable color is selected (STP6).
[0052]
For graphic data, for example, a dither pattern “resolution priority” (STP5) suitable for expressing a fine figure or a thin line due to the characteristics of hardware, or a stable color when a large figure or a large area is painted out. A dither pattern “gradation priority” (STP6) suitable for expression is selected.
[0053]
After the dither pattern is selected as described above, the printer command is converted (STP7), and the print data is transmitted to the printer device 24. The printer device 24 performs a printing process in accordance with the print data. At that time, the dither pattern selected by the above-described process is used, and the dithering process is performed by using an optimal dither pattern according to the size of the character or figure. For example, small characters and figures are easy to see and visibility are improved, and large characters and large figures can achieve color printing excellent in gradation, color reproducibility and stability.
[0054]
Note that the flowchart shown in FIG. 18 is a modification of the present embodiment, and the processing will be described below. In this case, text data and image data are not targeted.
As described above, the print data created by the application 22 is sent to the printer driver 23 through the operating system 21. The printer driver 23 determines the drawing attribute (STP1) and converts the input print data into text, graphics, images (photos). Are classified into three attributes.
[0055]
Next, it is determined whether or not the graphic data is "automatic" (STP8). If it is not "automatic", a designated dithering process is performed similarly to the image (STP9). Next, the shape of the figure is determined (STP10). This determination is performed, for example, on the angle of the line (the edge of the figure). Generally, a dither pattern has an angle (screen angle), and the angle differs for each color or for each type of dither pattern due to various factors such as hardware characteristics, color characteristics of color materials, and the purpose of color expression. That is, the angle of the line at which the dither pattern is good differs depending on the angle.
[0056]
Thus, in determining the shape of a figure, the angle of the edge of the figure (for example, the angle at which a line is drawn) is determined, the type of dither pattern corresponding to the angle is predetermined, and the optimal dither pattern is selected (STP11). , STP12).
Subsequent processing is the same as that described above, the printer command is converted (STP7), and the print data is transmitted to the printer device 24. The printer device 24 performs a printing process in accordance with the print data. At this time, the dither pattern selected by the above-described process is used.
[0057]
Therefore, by performing the processing as described above, the optimal dither pattern can be selected, and the edges of the figure can be expressed smoothly.
[0058]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to prevent the occurrence of jitter and streaks, and to perform a printing process that substantially matches the attributes of a drawing object.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram of a printing apparatus used in a first embodiment.
FIG. 2 is a diagram illustrating an example of a data configuration registered in a drawing object size table.
FIG. 3 is a flowchart illustrating processing of a print data receiving unit.
FIG. 4 is a flowchart illustrating processing of a print data drawing unit.
FIG. 5 is a flowchart illustrating a process of a screen pattern selection and development unit.
FIG. 6 is a flowchart illustrating processing of a drawing object size recognition unit.
FIG. 7 is a flowchart illustrating processing of a drawing data transfer unit.
FIG. 8 is a system configuration diagram of a printing apparatus used in a second embodiment.
FIG. 9 is a diagram illustrating an example of a data configuration registered in a reference difference value table.
FIG. 10 is a flowchart illustrating processing of a print data drawing unit.
FIG. 11 is a flowchart illustrating a process of a screen pattern selection and development unit.
FIG. 12 is a flowchart illustrating processing of a drawing object size recognition unit.
FIG. 13 is a diagram illustrating an example of a maximum difference value.
FIG. 14 is a diagram illustrating an example of a maximum difference value.
FIG. 15 is a configuration diagram of a printing system used in a third embodiment.
FIG. 16 is a diagram showing a condition setting dialog box at the time of conversion processing by a printer driver.
FIG. 17 is a flowchart illustrating a third embodiment.
FIG. 18 is a flowchart illustrating a modification of the third embodiment.
[Explanation of symbols]
1 Print data receiving unit
2 Host device
3 Print data holding buffer
4 Print data drawing unit
5 Screen pattern data expansion buffer
6. Image memory
7 Drawing data transfer section
8 Screen pattern selection and development section
9 Drawing object size recognition unit
10 Screen pattern data storage
11 Drawing object size table
12 Printer Engine
13 Unit area drawing data buffer
14 Reference difference value table
15 Unit area drawing data buffer
20 Personal computer (PC)
21 Operating System (OS)
22 Printing Applications
23 Printer Driver
24 Printer

Claims (3)

In a printing apparatus equipped with a plurality of screens having different numbers of lines and using the screen while switching, and performing a printing process based on drawing data
Means for recognizing the print data for each drawing object;
Means for calculating the print size of the recognized drawing object;
Means for selecting one of the plurality of screens having different numbers of lines based on the calculated print size;
Means for using the selected screen and generating the drawing data using the selected screen based on the recognized drawing object;
A printing device comprising: In a printing apparatus equipped with a plurality of screens having different numbers of lines and using the screen while switching, and performing a printing process based on drawing data
Means for dividing print data per unit area;
Means for calculating the degree of color variation from the divided print data per unit area,
Means for selecting one of the plurality of screens having different numbers of lines according to the degree of color variation;
Means for generating drawing data using the selected screen based on the divided print data per unit area,
A printing device comprising: 2. The printing apparatus according to claim 1, wherein the drawing objects are character data, graphic data, and photographic image data.

Images