JP2005033337A - Color image output apparatus and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color printer for outputting a proof print by using binary image data for platemaking. <P>SOLUTION: A screen condition discrimination means 21 acquires input binary image data and a processing condition of screen processing applied to the input binary image data at generation of the input binary image data, and discriminates whether or not an image output section 202 can output an image on the basis of the input binary image data by using the processing condition. When the image output section 202 cannot output the image, a multi-value conversion means 23 applies multi-value processing to the input binary image data to produce multi-value image data, and a color conversion means 24 carries out color conversion of the multi-value image data. A binary conversion means 25 applies the screen processing to the multi-value image data subjected to color conversion according to the processing condition under which the image output section 202 can output the image to generate output binary image data. When the image output section 202 can output the image on the basis of the input binary image data, a binary image tone correction means 26 generates the output binary image data by applying binary image tone correction to the input binary image data. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for outputting image data created for a certain image output device to another image output device having different output characteristics.
[0002]
[Prior art]
Conventionally, as a method of color proofing for printing, a method using a film prepared for plate making has been the mainstream. However, with the widespread use of CTP (Computer to Plate), which performs plate making directly from image data using a digital plate making machine, there is an increasing demand for outputting proofs using binary image data for plate making and using them for color proofing. It was. Although there is DDCP (Direct Digital Color Proof) as a technology that meets this demand, there is a problem that the user's financial burden becomes heavy because an expensive dedicated machine is used.
[0003]
On the other hand, it is convenient if the binary image data for plate making can be input to the color printer already owned by the user and the proof can be output. However, color printers are generally not suitable for color proofing because their color output characteristics are different from those of a printing machine used in actual printing. In order to solve this problem, color correction is performed to adjust image data to be supplied to the color printer so that the color tone of the output image from the color printer matches the color tone of the printed matter of the main print. Specifically, first, the color measurement patch image data is input to the color printer, and the color measurement patch image is output. Next, the side color value of the colorimetric patch output from the color printer is obtained using a spectrophotometer. This side color value is compared with the side color value of the colorimetric patch printed by the printing machine, and a color conversion processing coefficient used for color conversion to be applied to image data given to the color printer is obtained. Color conversion of the image data is performed using the processing coefficients for color conversion, and the image data having the same color tone as that printed by the printing press is output from the color printer by giving the color converted image data to the color printer. Is done. In this way, color proofing using a proof printed by a color printer becomes possible.
[0004]
Various techniques have been proposed for color correction of binary image data. In the technique described in Patent Document 1, binary image data is converted into multi-values, image processing such as color correction is performed, error diffusion is performed, and binary image data is output. The correction is realized. In the technique described in Patent Document 2, binary image data is converted into multivalued data, and a color correction value for the multivalued image data is obtained. Then, color correction is performed by adding the color correction value to the image data having halftone dot information before multi-value conversion, and then error diffusion is performed to output binary image data. As a result, the color correction with the halftone dot information remaining is realized.
[0005]
[Patent Document 1]
Japanese Patent No. 2877356 [Patent Document 2]
Japanese Patent Laid-Open No. 2001-144799
[Problems to be solved by the invention]
By the way, in the above-described prior art, even if the color printer receives the binary image data for plate making, depending on the processing conditions of the screen processing performed when the binary image data for plate making is generated, May not be output as. For example, in general, the number of screen lines that can suitably reproduce a natural image increase with a color printer is 200 lpi (line per inch) or less, and color image data for plate making is generated with screen lines exceeding this number. Cannot properly reproduce it as an image.
[0007]
The present invention has been made in view of the above-described circumstances, and an object of the present invention is the case where binary image data for plate making subjected to screen processing under conditions that the color printer does not support is given to the color printer. Even if it exists, it exists in enabling the output of the proof by a color printer.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides an image output unit that outputs an image based on input binary image data, and screen processing that is performed when the input binary image data and the input binary image data are generated. Screen condition determining means for determining whether or not the image output unit can output an image based on the input binary image data using the processing condition; and the input binary image data A multi-value conversion unit that multi-values the input binary image data to generate multi-value image data when the image output unit cannot output an image based thereon, and a color conversion unit that performs color conversion of the multi-value image data Screen processing is performed on the multi-valued image data color-converted by the color converting means according to processing conditions that can be output by the image output unit, and the multi-valued image data subjected to the screen processing is binarized to output a binary image. A binary conversion means for generating data, and when the image output unit can output an image based on the input binary image data, the input binary image data is subjected to binary image tone correction and output binary image Provided is a color image output device comprising binary image tone correction means for generating data.
[0009]
According to another aspect of the present invention, a computer device acquires input binary image data and processing conditions for screen processing performed when the input binary image data is generated, and an image based on the input binary image data is acquired as the image. A screen condition determining step for determining whether or not the output unit can output using the processing condition; and when the image output unit cannot output an image based on the input binary image data, the input binary image data is A multi-value conversion step of generating multi-value image data by multi-value conversion, a color conversion step of performing color conversion of the multi-value image data, and the image output unit to the multi-value image data color-converted by the color conversion means A binary conversion step of performing screen processing according to processing conditions that can be output, binarizing the screen-processed multi-value image data to generate output binary image data, and the input 2 In order to execute a binary image tone correction step of performing binary image tone correction on the input binary image data to generate output binary image data when the image output unit can output an image based on the image data. Provide a program.
[0010]
According to the present invention, the screen condition determination unit acquires the input binary image data and the processing conditions of the screen processing performed when the input binary image data is generated, and an image based on the input binary image data is obtained. Whether or not the image output unit can output is determined using the processing condition. Multi-value conversion means multi-values the input binary image data to generate multi-value image data when the image output unit cannot output an image based on the input binary image data. Color conversion means performs color conversion of the multi-value image data. The binary conversion means performs screen processing on the multi-valued image data color-converted by the color conversion means according to the processing conditions that can be output by the image output unit, and binarizes and outputs the screen-processed multi-valued image data Binary image data is generated. When the image output unit can output an image based on the input binary image data, the binary image tone correction means performs binary image tone correction on the input binary image data to generate output binary image data To do.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
(1. First embodiment)
(1-1. Configuration)
FIG. 1 is a diagram showing a configuration according to the first embodiment of the present invention. In the configuration shown in FIG. 1, a client device 10, a color printer 20, a RIP server 40 and a plate making machine 50 are connected via a LAN (Local Area Network) 2.
[0012]
The client device 10 is a computer having a normal hardware configuration, and exchanges data with other devices via the LAN 2. The client device 10 displays an input screen that prompts the user to input the file name, processing conditions, etc. of the image data, and the operator can input the data using a keyboard and a mouse (not shown).
[0013]
The RIP server 40 acquires vector data described in a page description language such as Post Script, converts the vector data into raster data, and performs screen processing to generate binary image data for plate making. The RIP server 40 in this embodiment can generate binary image data for plate making with a resolution of 2400 dpi (dot per inch). It is also possible to select other resolutions. The binary image data for plate making generated by the RIP server 40 is, for example, image data in a TIFF (Tagged Image File Format) format, and includes screen processing conditions and resolution information.
[0014]
The color printer 20 is used for acquiring binary image data for plate making created by the RIP server 40 and outputting a proof.
In the present embodiment, the proof printing binary image data outputted from the RIP server 40 is proofread using this proof print.
The plate making machine 50 is a digital plate making machine that receives the calibrated binary image data for plate making from the RIP server 40, and based on this, directly exposes the plate material to produce a printing plate.
The printing machine 60 performs multicolor printing using the printing plate produced by the plate making machine 50.
[0015]
Next, the configuration of the color printer 20 will be described. As shown in FIG. 1, the color printer 20 includes a controller 201 and an image output unit 202. Here, the image output unit 202 is an electrophotographic image output apparatus that outputs an image under the control of the controller 201. The image output unit 202 can output an image having the same resolution as the RIP server 40 (here, 2400 dpi). The configuration of the controller 201 is shown in FIG.
A CPU (Central Processing Unit) 30 executes a program stored in a ROM (Read Only Memory) 31 to perform control for generating a proof print by the image output unit 202. A RAM (Random Access Memory) 32 is used as a work area at that time.
The transmission / reception unit 33 transmits / receives data to / from other devices connected to the LAN 2 under the control of the CPU 30.
The storage means 34 is a mass storage device such as a hard disk drive.
Screen condition determination means 21, screen condition analysis means 22, multi-value conversion means 23, color conversion means 24, binary conversion means 25, and binary image tone correction means 26 are executed by CPU 30 to generate a proof. Software module. Hereinafter, these functions will be described.
[0016]
The screen condition determining means 21 acquires the screen processing condition included in the plate-making binary image data, and uses the screen processing condition to determine whether or not the plate-making binary image data can be output by the image output unit 202. This is a module for judging.
[0017]
The screen condition analysis means 22 performs a Fourier transform on the binary image data for plate making, and screen processing applied to the binary data for plate making based on the spatial frequency characteristics of the binary image data for plate making obtained as a result. This module acquires the screen type, the number of screen lines, and the screen angle.
[0018]
The multi-value conversion means 23 is a module that converts the binary image data for plate making into multi-value image data indicating an image having a halftone from which the halftone dot structure has been removed. A method for converting the binary image data for plate making into multi-valued image data is disclosed in Patent Document 1, for example.
[0019]
The color conversion unit 24 is a module that performs color conversion on the multi-valued image data to match the color tone of the output image from the color printer 20 with the color tone of the printed matter by the printer 60 using the color conversion coefficient. Here, the color conversion coefficient is obtained in advance based on the difference in the output characteristics of the color printer 20 with respect to the output characteristics of the printing press 60, and is stored in the storage unit 34. The color conversion coefficient can be created using, for example, a method disclosed in Japanese Patent Application Laid-Open No. 2002-152543.
[0020]
The binary conversion means 25 is a module that performs screen processing on multi-valued image data to convert it into image data having halftone dot information, and further converts it into binary image data.
[0021]
The binary image tone correction means 26 is a module for performing tone correction using pre-created tone correction values for the plate-making binary image data when it is not necessary to change the screen processing conditions. Here, the tone correction value is such that the output image obtained from the color printer 20 reproduces the color of the printed matter by the printer 60 when tone correction is performed using the tone correction value.
Note that the above modules may be configured by hardware, and the CPU 30 may control these modules to advance the process for proof printing output.
[0022]
(1-2. Operation)
The operation realized by the above configuration will be described. Here, it is assumed that the binary image data D1 for plate making has been created by the RIP server 40 and stored in the RIP server 40. In the present embodiment, the color printer 20 does not support FM (Frequency Modulation) screen processing and AM (Amplitude Modulation) screen processing with a high line number exceeding 200 lpi (line per inch). .
[0023]
First, when an operator inputs a file name of binary image data D1 for plate making to be proofed to the client apparatus 10, this file name is supplied from the client apparatus 10 to the RIP server 40. The RIP server 40 transmits to the color printer 20 an output instruction for the plate-making binary image data D1 specified by the file name.
[0024]
When the CPU 30 of the color printer 20 receives an output instruction from the RIP server 40 via the transmission / reception unit 33, the CPU 30 executes a program whose flow is shown in FIG.
First, the CPU 30 receives the plate-making binary image data D1 from the RIP server 40 (step S01), and delivers it to the screen condition determining means 21. The screen condition determining means 21 determines whether or not screen processing conditions are included in the plate-making binary image data D1 (step S02), and if included, acquires the screen processing conditions (step S03). ). On the other hand, if the screen processing conditions are not included, the CPU 30 delivers the plate-making binary image data D1 to the screen condition analyzing means 22. Then, the screen condition analysis means 22 obtains the spatial frequency characteristics of the plate-making binary image data D1 by Fourier transform, and based on the spatial frequency characteristics, conditions for screen processing applied to the plate-making binary image data D1. Is acquired (step S04).
[0025]
Next, the CPU 30 makes a determination regarding the acquired screen processing condition. First, the CPU 30 determines the screen type (step S05). If the screen type is an AM screen, the CPU 30 determines the number of screen lines (step S06). Here, if the screen line number is 200 lpi or less, the plate-making binary image data D1 can be output by the image output unit 202, and therefore only tone correction may be performed without changing the screen conditions. Therefore, in this case, the CPU 30 delivers the plate-making binary image data D1 to the binary image tone correcting means 26. The binary image tone correction means 26 performs tone correction of the binary image data for plate making using a tone correction coefficient stored in advance, and generates binary image data D2 for the printer (step S07).
[0026]
On the other hand, if the screen type is FM screen in step S05, it is necessary to change the screen processing conditions, so the CPU 30 delivers the plate-making binary image data D1 to the multi-value conversion means 23. Further, also when the screen type is AM in step S05 and the screen line number exceeds 200 lpi in step S06, the CPU 30 delivers the plate-making binary image data D1 to the multi-value conversion means 23.
The multi-value conversion means 23 multi-values the binary image data D1 for plate making and generates multi-value image data D3 (step S08).
[0027]
Next, the CPU 30 delivers the multi-value image data D3 to the color conversion means 24. The color conversion unit 24 performs color conversion of the multi-value image data D3 using a color conversion coefficient stored in advance, and generates multi-value image data D4 (step S09).
[0028]
The CPU 30 receives the multi-value image data D4 from the color conversion means 24 and passes it to the binary conversion means 25. In the binary conversion means 25, the multi-valued image data D4 is subjected to screen processing under a condition that can be output by the image output unit 202 and that is closest to the screen processing condition applied to the plate-making binary image data D1. Printer binary image data D5 is generated (step S10). In this operation example, the image output unit 202 outputs binary image data that has been subjected to screen processing under the condition that the screen type is an AM screen, the screen line number is 200 lpi or less, and the screen angle is an arbitrary angle. Is possible. Therefore, the binary conversion means 25 selects the one closest to the screen processing conditions applied to the plate-making binary image data D1 within this range, and performs the screen processing of the multi-value image data D4 according to the selected conditions. Do it.
[0029]
When the binary image tone correction unit 26 generates the printer binary image data D2 (step S07) or the binary conversion unit 25 generates the printer binary image data D5 (step S10). The generated binary image data for printer D2 or D5 is delivered to the image output unit 202. The image output unit 202 outputs a proof print based on the binary image data D2 or D5 for the printer.
[0030]
According to the present embodiment, even when the screen processing conditions applied to the plate-making binary image data D1 are conditions that the image output unit 202 cannot output, the plate-making binary image data D1 is input to the color printer 20. Thus, an image can be output under screen processing conditions close to a printed matter by the printing press 60.
[0031]
Further, by analyzing the spatial frequency characteristics of the plate-making binary image data D1 and acquiring the screen processing conditions, the screen processing conditions can be determined even when the screen processing conditions are not included in the image data.
[0032]
(2. Second Embodiment)
(2-1. Configuration)
FIG. 4 is a diagram showing a configuration according to the second exemplary embodiment of the present invention. Constituent elements common to the first embodiment are denoted by the same reference numerals. The differences from the configuration according to the first embodiment are as follows.
As shown in FIG. 4, the color printer 20a includes a controller 201a and an image output unit 202a. As shown in FIG. 5, the controller 201 a includes a resolution determination unit 27 and a resolution conversion unit 28. The resolution determination unit 27 is a module that acquires resolution information of binary image data for plate making and determines whether the color printer 20a can output an image having a resolution represented by the acquired resolution information. The resolution conversion means 28 is a module that converts image data into image data with different resolutions.
[0033]
The resolution of the image that can be output by the image output unit 202a is assumed to be lower (for example, 600 bpi) than the resolution (2400 bpi) when the RIP server 40 generates the binary image data D1 for plate making. The image output unit 202a may be capable of selecting an output resolution at 600 bpi or less.
[0034]
(2-2. Operation)
The operation realized by the above configuration will be described. As in the first embodiment, it is assumed that the binary image data D1 for plate making has been created by the RIP server 40 and stored in the RIP server 40. Also in this embodiment, it is assumed that the color printer 20a does not support FM screen processing and AM screen processing with a high line number exceeding 200 lpi (line per inch).
[0035]
First, the operator inputs a file name of the binary image data D1 for plate making to obtain a proof print to the client device 10. The input file name is supplied to the RIP server 40. The RIP server 40 transmits to the color printer 20a an output instruction for the plate-making binary image data D1 specified by the file name.
[0036]
When the CPU 30 of the color printer 20a receives an output instruction from the RIP server 40 via the transmission / reception unit 33, the CPU 30 executes a program whose flow is shown in FIG.
First, the CPU 30 receives the plate-making binary image data D1 and the resolution information from the RIP server 40 (step S21), and delivers them to the resolution determination means 27. The resolution determination unit 27 determines whether or not resolution information is included in the plate-making binary image data D1 (step S22), and if included, acquires the resolution information (step S23). On the other hand, when the resolution information is not included, the CPU 30 transmits a request message for requesting input of the resolution information of the binary image data D1 for plate making to the client device 10. Upon receiving this request message, the client device 10 displays a screen that prompts the operator to input resolution information. The operator inputs resolution information of the plate-making binary image data D1 to the client device 10 and transmits it to the color printer 20a. When the color printer 20a receives the resolution information, the CPU 30 delivers this resolution information to the resolution determination means 27 (step S24).
[0037]
Next, the CPU 30 delivers the plate-making binary image data D1 to the screen condition determining means 21. The screen condition determining means 21 determines whether or not screen processing conditions are included in the plate-making binary image data D1 (step S25), and if included, acquires the screen processing conditions (step S26). ). On the other hand, if the screen processing conditions are not included, the CPU 30 delivers the plate-making binary image data D1 to the screen condition analyzing means 22. The screen condition analyzing means 22 obtains the spatial frequency characteristics of the plate-making binary image data D1 by Fourier transform, and based on the spatial frequency characteristics, the screen processing conditions applied to the plate-making binary image data are determined. Obtain (step S27).
[0038]
Next, the CPU 30 compares the resolution of the binary image data for plate making D1 represented by the acquired resolution information with the output resolution of the color printer 20a (step S28), and if the two resolutions match, the process proceeds to step S29. move on. The processing from step S29 to S31 is the same as the processing from step S05 to S07 in the first embodiment, and the binary image data D2 for the printer subjected to the binary image tone correction by the binary image tone correction means 26. Is generated. On the other hand, if the two resolutions are different, the process proceeds to step S32.
[0039]
In step S <b> 32, the CPU 30 delivers the plate-making binary image data D <b> 1 to the multi-value conversion unit 23. The multi-value conversion means 23 multi-values the binary image data D1 for plate making and generates multi-value image data D3. Next, the CPU 30 delivers the multi-value image data D3 to the resolution conversion means 28. The resolution conversion means 28 converts the multi-value image data D3 into multi-value image data D6 having a resolution closest to the resolution of the plate-making binary image data D1 within a range that can be output by the image output unit 202a (step S33). ). In this operation example, the image output unit 202a can output binary image data having a resolution of 600 dpi or less. Therefore, within this range, the resolution conversion means 28 selects the resolution closest to the resolution of the plate-making binary image data D1, and converts the multi-value image data D3 to the selected multi-value image data D6. .
[0040]
In step S <b> 34, the CPU 30 delivers the multi-value image data D <b> 6 to the color conversion unit 24. The color conversion unit 24 performs color conversion of the multi-value image data D5 with reference to color conversion coefficients stored in advance, and generates multi-value image data D7.
[0041]
In step S35, the CPU 30 delivers the multi-value image data D6 to the binary conversion means 25. The binary conversion means 25 performs screen processing on the multi-valued image data D6 under conditions that can be output by the image output unit 202a and that is closest to the screen processing conditions applied to the plate-making binary image data D1, Printer binary image data D8 is generated.
[0042]
When the binary image tone correcting unit 26 generates the binary image data D2 for the printer (step S31) or the binary conversion unit 25 generates the binary image data D8 for the printer (step S35). The generated binary image data for printer D2 or D8 is delivered to the image output unit 202a. The image output unit 202a outputs a proof print based on the binary image data D2 or D8 for the printer.
[0043]
According to the present embodiment, even when the resolution of the binary image data D1 for plate making is a resolution that cannot be output by the image output unit 202a, the binary image data D1 for plate making is input to the color printer 20a and the printing machine 60 is used. It is possible to output an image with a resolution close to that of a printed matter.
[0044]
(3. Modified examples)
The present invention is not limited to the form described above, and can be implemented in various forms. For example, the embodiment described above can be modified as follows.
[0045]
The present invention may be modified such that the above-described program executed by the CPU is stored in an external server, and this program is downloaded from an external server via a communication network such as the Internet. Further, the program is stored in an external server, binary image data for plate making is transmitted to the server via the communication network, and binary image data for printer is generated by causing the server to execute the above-described program. Thus, the present invention may be modified.
[0046]
In the case of an AM screen, the present invention may be modified to reproduce a halftone dot shape in addition to the screen line number and the screen angle.
Normally, a color patch having a halftone dot area ratio of 50% is output at the periphery of the image represented by the image-making image data. A halftone dot shape can be determined by cutting out one halftone dot from the color patch and comparing it with various halftone dot masks. If the above-described color patch does not exist, it is possible to search and determine a part having an area ratio of about 50% in the image.
[0047]
When the screen processing conditions are not included in the plate-making binary image data, the present invention may be modified to estimate the screen line number from the resolution of the image. Generally, in order to output an image having a screen line number Nlpi, a resolution of 2 Nbpi or higher is required. Therefore, if the resolution of the image is 2 Nbpi, the number of screen lines is Nlpi at the maximum. Therefore, in this case, assuming that the screen line number is Nlpi, the binary image data for the printer may be created with the closest screen line number.
[0048]
For the color printer, the present invention may be modified to use, for example, an ink jet type color printer other than the electrophotographic system.
[0049]
【The invention's effect】
According to the present invention, it is possible to output a proof print from a color printer using binary image data for plate making.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a configuration of a controller 201 according to the same embodiment.
FIG. 3 is a flowchart showing a flow of processing executed by a controller 201 according to the embodiment;
FIG. 4 is a diagram illustrating a configuration according to a second embodiment of the present invention.
FIG. 5 is a diagram showing a configuration of a controller 201a according to the same embodiment.
FIG. 6 is a flowchart showing a flow of processing executed by the controller 201a according to the same embodiment;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 2 ... LAN, 10 ... Client apparatus, 20 ... Color printer, 40 ... RIP server, 50 ... Plate making machine, 60 ... Printing machine, 201 ... Controller, 202 ... Image output part, 21 ... Screen condition determination means, 22 ... Screen condition Analysis means 23... Multi-value conversion means 24. Color conversion means 25. Binary conversion means 26. Binary image tone correction means 30... CPU 31. ROM ROM 32. ... memory means

Claims (4)

An image output unit for outputting an image based on the input binary image data;
The input binary image data and the processing conditions of the screen processing performed at the time of generating the input binary image data are acquired, and whether or not the image output unit can output an image based on the input binary image data is determined. Screen condition determining means for determining using processing conditions;
Multi-value conversion means for generating multi-value image data by converting the input binary image data into multi-values when the image output unit cannot output an image based on the input binary image data;
Color conversion means for performing color conversion of the multi-value image data;
Screen processing is performed on the multi-valued image data color-converted by the color converting means according to processing conditions that can be output by the image output unit, and the screen-processed multi-valued image data is binarized to generate output binary image data Binary conversion means for
Binary image tone correction means for performing binary image tone correction on the input binary image data to generate output binary image data when the image output unit can output an image based on the input binary image data; A color image output device comprising: Resolution determination means for acquiring resolution information indicating the resolution of the input binary image data, and determining whether the image output unit can output an image having the resolution;
A resolution conversion means for converting the resolution of the multivalued image data,
The multi-value conversion unit generates multi-value image data by converting the binary image data into a multi-value when the image output unit cannot output an image having the resolution. Color image output device. A spatial frequency characteristic of an image represented by the input binary image data is obtained by performing a Fourier transform on the input binary image data, and screen processing performed when the input binary image data is generated using the spatial frequency characteristic. Equipped with screen condition analysis means for obtaining processing conditions,
The screen condition determination means acquires the screen processing condition when the screen processing condition is included in the binary image data, while the screen processing condition is not included in the binary image data. The color image output apparatus according to claim 1, wherein the screen processing condition is obtained by the screen condition analyzing means. Computer equipment,
The input binary image data and the processing conditions of the screen processing performed at the time of generating the input binary image data are acquired, and whether or not the image output unit can output an image based on the input binary image data is determined. A screen condition determination step for determining using processing conditions;
A multi-value conversion step of generating multi-value image data by converting the input binary image data into multi-values when the image output unit cannot output an image based on the input binary image data;
A color conversion step for performing color conversion of the multi-value image data;
Screen processing is performed on the multi-valued image data color-converted by the color converting means according to processing conditions that can be output by the image output unit, and the screen-processed multi-valued image data is binarized to generate output binary image data A binary conversion step,
A binary image tone correction step for generating binary image tone data by performing binary image tone correction on the input binary image data when the image output unit can output an image based on the input binary image data; A program for running

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