JP2004255610A - Control method of image formation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To highly precisely carry out judgement on whether it is color or monochrome, for improving the throughput of a printing process. <P>SOLUTION: A threshold for color judgment is determined by the presence/absence of a gray compensation profile in the middle of a printing job (S3103 and S3104). A search process of whether or not a recording color component of not smaller than the threshold is present in each object is carried out in S3105 to S3111. When it is detected during the process that there is the object with the recording color component over the threshold (S3107 and S3109), the search afterwards is stopped, and it is judged that a target page is color (S3110). In the case where no component over the threshold is found in spite of the search carried out for all the objects, the target page is judged as monochrome (S3112). <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technique for forming a color image based on print data described in a page description language.
[0002]
[Prior art]
Conventionally, in a color printer having different output speeds for color output and monochrome output, in order to improve the total throughput of the printing process, for data in which monochrome pages and color pages are mixed, it is determined whether each page is a monochrome page or a color page. That is being done.
[0003]
Also, if a page consisting only of gray scales is output in color, overcoating is performed with each of the CMYK toners and the print quality will be degraded. In the case of a color MFP, different maintenance fees will be charged for color output and monochrome output. In some cases, the count was set contrary to the user's expectation.
[0004]
To cope with these problems, the CMKY value used on each page is checked, and if a CMY value is detected, it is determined that the color is a color. If the input RGB values used on each page are equal, monochrome is used. The problem has been solved by additionally introducing a method of determining the gray level and a mechanism for compensating for gray in color management.
[0005]
[Problems to be solved by the invention]
However, in the case of a page description language having various input color spaces such as PostScript (registered trademark), or in the case of performing color management using an ICC (International Color Consortium) profile, a user can display gray pages on an application. Even with the intentional configuration, there were cases in which not only black but also cyan, magenta, and yellow components were delicately output due to calculation errors in color processing, and as a result, color was output.
[0006]
The present invention has been made in view of such a problem, and an object of the present invention is to provide a technique for determining a color or a monochrome with high accuracy in order to improve the throughput of a printing process.
[0007]
[Means for Solving the Problems]
In order to solve this problem, for example, a control method of an image forming apparatus according to the present invention includes the following configuration. That is,
Generating means for generating bitmap image data of each recording color component based on print data described in a page description language, and printing a color image on a predetermined recording medium based on the generated bitmap image data by the printing means A method for controlling an image forming apparatus, comprising:
A search step of sequentially searching, for each object described in the page description language, whether or not data relating to a recording color component exceeds a predetermined threshold value;
If it is determined during the search process that there is an object having a recording color component exceeding the threshold value, the subsequent search is stopped, and a first determination step is performed to determine that the page of interest is a color page;
A second determining step of determining that the page of interest is a monochrome page when all objects are equal to or less than the color component equal to or less than the threshold value by the search processing in the searching step;
If it is determined in the first determining step that the page is a color page, the printing is performed by the printing unit based on the bitmap image data of each recording color component generated by the generating unit, and the second determining unit performs printing. A control step of causing the printing means to print using only the black bitmap image data generated by the generating means when it is determined that the page is a monochrome page.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0009]
FIG. 1 is a block diagram illustrating the overall configuration of the image forming apparatus system according to the present embodiment. The image forming apparatus 200 includes a scanner unit 2070 as an image input device, a printer unit 2095 as an image output device, a control unit 2000, and an operation unit 2012 as a user interface. The scanner unit 2070, the printer unit 2095, and the operation unit 2012 are each connected to a control unit 2000, and the control unit 2000 is connected to a network transmission unit such as a LAN 2011. Further, other image forming apparatuses 220 and 230 having the same device configuration as the image forming apparatus 200 and computers 101 and 102 such as personal computers are connected to the LAN 2011. The image forming apparatuses 220 and 230 have scanner units 2270 and 2370, printer units 2295 and 2395, and operation units 2212 and 2312, respectively, which are connected to the control units 2200 and 2300.
[0010]
FIG. 2 is a software block diagram of the image forming apparatus 200 according to the present embodiment. However, the same applies to the image forming apparatuses 220 and 230.
[0011]
In the figure, reference numeral 1501 denotes a UI, that is, a user interface, which is a module that mediates with an apparatus when an operator performs various operations and settings of the image forming apparatus. This module transfers input information to various modules, which will be described later, and requests processing or sets data according to the operation of the operator. Reference numeral 1502 denotes a database module for managing an address-book, that is, a data transmission destination, a communication destination, and the like. The contents of the Address-Book are used to add, delete, and acquire data by an operation from the UI 1501 and to provide data transmission / communication destination information to each module described later by an operation of an operator.
Reference numeral 1504 denotes a Universal-Send, that is, a module that manages data distribution, and distributes data specified by the UI 1501 to the operator to a communication (output) destination similarly specified. When the operator instructs generation of distribution data using the scanner function of the apparatus, the apparatus operates the apparatus via a Control-API 1519 described later to generate data. Reference numeral 1505 denotes a module that is executed when a printer is specified as an output destination in the Universal-Send 1504. A module 1506 is executed when an E-mail address is specified as a communication destination in the Universal-Send 1504. Reference numeral 1507 denotes a module that is executed when a database is specified as an output destination in the Universal-Send 1504. Reference numeral 1508 denotes a module that is executed when an image forming apparatus similar to the present apparatus is designated as an output destination in the Universal-Send 1504.
[0012]
Reference numeral 1509 denotes a PDL module, which implements a function of printing a PDL (Page Description Language) document transmitted from outside the image forming apparatus using the print function of the image forming apparatus. It also provides a function of extracting and printing an electronic document stored in an external Web server using a 1512 HTTP module.
[0013]
Reference numeral 1510 denotes a Copy module that executes a copying operation based on an instruction from the UI, using a printer function and a scanner function of the image forming apparatus.
[0014]
Reference numeral 1511 denotes a box module (Box) that stores a scanned image or a PDL print image in a storage device such as an HDD, prints the stored image using a printer function, transmits the stored image using a Universal-Send function, deletes a document stored in the HDD, It provides management functions such as grouping (storage in individual boxes), movement between boxes, and copying between boxes.
[0015]
Reference numeral 1512 denotes a module used when the image forming apparatus communicates by HTTP, and provides communication to the above-described PDL 1509 module by a TCP / IP 1516 module described later. Reference numeral 1513 denotes an lpr module, which provides communication to the printer module 1505 in the above-mentioned Universal-Send 1504 by a TCP / IP 1517 module described later. Reference numeral 1514 denotes an SMTP module, which provides communication to the E-mail module 1506 in the above-mentioned Universal-Send 1504 by a TCP / IP 1517 module described later. Reference numeral 1515 denotes an SLM, that is, a Salutation-Manager module, which provides communication to a database module 1517 and a DP module 1518 in the above-mentioned Universal-Send 1504 by a TCP / IP 1517 module described later. Reference numeral 1516 denotes an LPD module, which provides communication to the above-described PDL 1509 module by a TCP / IP 1517 module described later.
[0016]
Reference numeral 1517 denotes a TCP / IP communication module, which provides network communication to the above-described various modules using a Network-Driver described later. Reference numeral 1518 denotes a network driver which controls a portion physically connected to the network.
[0017]
Reference numeral 1519 denotes a Control-API, which provides an interface with a lower module such as a Job-Manager 1520 to be described later for a higher module such as Universal-Send 1504, PDL 1509, Copy 1510, and Box 1511. And to reduce the dependency between lower-level modules and enhance their diversion.
[0018]
Reference numeral 1520 denotes a Job-Manager, which interprets a process instructed by the above-described various modules via the Control-API 1519 and gives an instruction to each module described later. Further, this module centrally manages hardware processing executed in the image forming apparatus.
[0019]
Reference numeral 1521 denotes a CODEC-Manager, which manages and controls various types of data compression / decompression in the processing specified by the Job-Manager 1520. Reference numeral 1522 denotes an FBE-Encoder, which compresses data read by a scan process executed by the Job-Manager 1520 and the Scan-Manager 1525 in the FBE format. Reference numeral 1523 denotes a JPEG-CODEC, which performs JPEG compression of read data and JPEG decompression of print data in scan processing executed by the Job-Manager 1520 and Scan-Manager 1525 and print processing executed by the Print-Manager 1526. Is what you do. Reference numeral 1524 denotes an MMR-CODEC, which performs MMR compression of read data and MMR decompression of print data in a scan process performed by the Job-Manager 1520 and the Scan-Manager 1525, and in a print process performed by the Print-Manager 1526. Processing is performed.
[0020]
Reference numeral 1525 denotes a Scan-Manager, which manages and controls a scan process specified by the Job-Manager 1520. Reference numeral 1528 denotes a Scanner I / F, which provides an I / F between the Scan-Manager 1524 and a scanner unit internally connected to the image forming apparatus.
[0021]
Reference numeral 1526 denotes a Print-Manager, which manages and controls print processing instructed by the Job-Manager 1519. An engine-I / F driver 1529 provides an interface between the print manager 1526 and the printing unit.
[0022]
Reference numeral 1527 denotes a PDL interpreter, which interprets a PDL or electronic document format such as LIPS, PostScript, PCL, PDF, or SVG according to an instruction of the Job-Manager 1520, and uses a common expression format that does not depend on the type of PDL or electronic document format. A display list is generated.
[0023]
Reference numeral 1530 denotes a Render, which renders a display list generated by the PDL Interpreter 1527 in a raster image memory using an image processor in accordance with an instruction from the Print-Manager 1520.
[0024]
FIG. 3 is a block diagram illustrating a configuration of the image forming apparatus 200 according to the embodiment.
[0025]
The control unit 2000 is connected to a scanner 2070 as an image input device and a printer 2095 as an image output device, and is connected to a LAN 2011 or a public line (WAN) 2051 to input and output image information and device information. It is a controller.
[0026]
In the control unit 2000, the CPU 2001 is a controller that controls the entire system. A RAM 2002 is a system work memory for the operation of the CPU 2002, and is also an image memory for temporarily storing image data. The ROM 2003 is a boot memory, and stores a system boot program. An HDD 2004 is a hard disk drive that stores system software and image data. When the apparatus is turned on, the CPU 2002 accesses the HDD 2004 according to the boot program in the ROM 2003, loads the system program into the RAM 2002, and executes the processing program having the configuration shown in FIG.
[0027]
An operation unit I / F 2006 is an interface unit with an operation unit (UI) 2012 and outputs image data to be displayed on the operation unit 2012 to the operation unit 2012. In addition, it plays a role of transmitting information input by the user of the system from the operation unit 2012 to the CPU 2001. A network I / F 2010 is connected to the LAN 2011 and inputs and outputs information. Since the image forming apparatus according to the embodiment also functions as a network printer, print data from the host computer shown in FIG. 1 is also printed via the network I / F 2010 (print data described in PostScript). Will be received. The Modem 2050 connects to the public line 2051 and inputs and outputs information. The above devices are arranged on the system bus 2007. An image bus I / F 2005 is a bus bridge that connects a system bus 2007 and an image bus 2008 that transfers image data at high speed, and converts a data structure.
[0028]
The image bus 2008 includes a PCI (Peripheral Component Interconnect) bus or an IEEE 1394. The following devices are arranged on the image bus 2008. An image processor (RIP) 2060 develops the display list into a raster image. The device I / F unit 2020 connects the scanner 20000 and the printer 2095, which are image input / output devices, to the controller 2000, and performs synchronous / asynchronous conversion of image data. The scanner image processing unit 2080 performs correction, processing, and editing on input image data. A printer image processing unit 2090 performs printer correction, resolution conversion, half-toning, and the like on print output image data. The image rotation unit 2030 rotates image data. The image compression unit 2040 performs JPEG compression on multi-valued image data and JBIG, MMR, and MH on binary image data. A card reader I / F 2015 is an interface of a card reader 2016 which is a magnetic card reader.
[0029]
FIG. 4 shows the appearance of the image forming apparatus. A scanner unit 2070, which is an image input device, illuminates an image on paper serving as a document, and scans and exposes the image with a CCD line sensor (not shown) to convert the image into raster image data 2071 into an electric signal. The manuscript paper is set on the tray 2073 of the manuscript feeder 2072, and when the apparatus user gives an instruction to start reading from the operation unit 2012, the controller CPU 2001 gives an instruction to the scanner 2070 (2071). Feeding is performed to read the original image. A printer unit 2095, which is an image output device, converts raster image data 2096 into an image on paper. The method is an electrophotographic method using a photosensitive drum or a photosensitive belt, and ink is ejected from a minute nozzle array. There is an ink jet system for printing an image directly on a sheet, and the like, but any system may be used.
[0030]
Activation of the printing operation is started by an instruction 2096 from the controller CPU 2001. The printer unit 2095 has a plurality of paper feed stages so that different paper sizes or different paper orientations can be selected, and includes paper cassettes 2101, 2102, and 2103 corresponding thereto. The paper discharge tray 2111 receives printed paper.
[0031]
Next, FIG. 5 illustrates a configuration of the operation unit 2012 of the image forming apparatus 200 according to the embodiment.
[0032]
The LCD display unit 2013 has a touch panel sheet 2019 affixed on the LCD, displays an operation screen and soft keys of the system, and transmits the position information to the controller CPU 2001 when a displayed key is pressed. A start key 2014 is used to start a reading operation of a document image. A two-color LED 2018 of green and red is provided at the center of the start key 2014, and the color indicates whether the start key 2014 is in a usable state. A stop key 2015 functions to stop an operation in operation. An ID key 2016 is used to input a user ID of a user. A reset key 2017 is used to initialize settings from the operation unit.
[0033]
FIG. 6 is a block diagram mainly showing the operation unit 2019 and the CPU 2001 of the image forming apparatus.
[0034]
In the image forming apparatus, reference numeral 2001 denotes a control CPU, which comprehensively controls access to various devices connected to the system bus 2007 based on a control program stored in a program ROM 2003 and a HDD 2004, and an image input unit. Input information is read from the scanner 2070 connected via the interface 2071, and an image signal as output information is output to the printing unit 2095 connected via the printing unit interface 2096. Reference numeral 2002 denotes a RAM that functions as a main memory, a work area, and the like of the CPU 2001. User input is received from the touch panel 2019 and the hard keys 2014 to 2017, and the operation content is acquired via the operation input unit I / F 20061. Display screen data is generated in the CPU 2001 based on the acquired operation content and the above-described control program, and the display screen is output to the screen output device 2013 such as an LCD or a CRT via the output device controller 20062 for controlling the screen output device. I do.
[0035]
Next, the interpretation of a page description language (print data output from a computer on a network) and the flow of image formation will be described with reference to FIG. 7, focusing on color processing. Here, PostScript (registered trademark) will be described as an example of the page description language.
[0036]
The interpreter 3001 is one of the PDL interpreters 1527 in FIG. 2 and interprets data described in the PostScript language to generate a display list 3011 as intermediate language data. The CMS engine 3004 is a module that performs color management, and converts an input color into an absolute color space and generates an output color (C (cyan) M (magenta) Y (yellow) K (black)) unique to the printer engine. It is. In the PostScript language, various color spaces such as a device color space, a CIE based color space, and a special color space are defined, and input colors specified in the device color space are prepared in advance such as an RGB source profile and a CMYK simulation profile. Color conversion is performed using a designated one of the ICC profile groups. For input colors specified in the CIEBased color space, color conversion is performed according to a conversion table, conversion function, and conversion matrix specified in the color space. The conversion from the absolute color space to the color space unique to the printer engine is performed using an output profile or Color Rendering Dictionary defined by PostScript. As for the output profile, a gray compensation profile that prioritizes that the gray scale is expressed by K single color and a normal profile that expresses the gray scale by four colors of CMYK can be selectively used.
[0037]
The color determination unit 3005 checks the CMYK colors, which are output values of the CMS engine, and determines whether the page currently being processed is a color page or a monochrome page. The display list generator 3006 generates a display list 3011 as intermediate language data. The display list includes an attribute flag of each object, and identifies whether the object is a graphic, an image, or a character. This attribute flag is used for subsequent image processing after rendering. The renderer 3002 interprets the display list and generates a bitmap 3012 each having a bit depth of 8 bits × 4 planes (= C, M, Y, K), and performs most processing using the RIP 2060 of FIG. Is performed.
[0038]
Further, the render 3002 generates an object attribute map 3013 indicating the attribute for each device pixel as a fifth plane based on the attribute flag included in the display list 3011. Here, the object attribute map has attribute information of bit depth 2 for each pixel. The breakdown of the two bits is, for example, a graphic “01”, an image “10”, and a character “11” in binary.
[0039]
The image processor 3003 is controlled by the print manager 1526 of FIG. 2 and performs image processing such as density / color balance adjustment 3007, output gamma correction 3008, and halftoning 3009 on the CMYK bitmap 3012 generated by the render 3002. It is. The halftoning 3009 refers to the object attribute map 3013 and applies different halftoning for each object attribute. For example, a high-frequency screen with priority on resolution is applied to an image area having a graphics attribute, Tone image attribute) is applied to a low-resolution screen for tone priority for an image region, and error diffusion is applied to an image region for a character attribute. For graphics, a dither matrix that emphasizes resolution is used, and for a halftone image, a dither matrix that emphasizes gradation is used. In short, it suffices if processing suitable for the image area can be performed.
[0040]
If the color determination unit 3005 determines that the page is a monochrome page, only the component K bitmap of the CMYK bitmap 3012 created by the render 3002 is sent to the image processor 3003, and the K bit used in the final output is output. A map 3015 is generated. If the color determination unit 3005 determines that the page is a color page, the CMYK bitmap 3012 generated by the render 3002 is sent to the image processor 3002 as it is, and the CMYK bitmap 3014 used in the final output is generated. You. In this way, the CMYK bitmap 3014 or the K bitmap 3015 generated by the image processor 3003 is transferred to the printer engine via the Engine I / F 1529 in FIG. 2 and printed out on a desired recording medium such as recording paper. is there.
[0041]
Next, a detailed processing procedure of the color determination unit will be described with reference to FIG.
[0042]
In the present apparatus, the color management process, the color determination process, and the display list generation process are sequentially performed for each object, and thus the flowchart shown in FIG. 8 is called for each object as a color determination routine.
First, starting from step S3101, it is determined in step S3114 whether or not the color determination of the current page is undecided. If it is already determined that the color is monochrome or monochrome, the process proceeds to step S3115 without performing color determination and ends. If not determined, it is determined in step S3102 whether or not the currently selected output profile is a gray compensation profile. If the output profile is the gray compensation profile, the process proceeds to step S3104; otherwise, the process proceeds to step S3103.
[0043]
In step S3103, the color determination thresholds Tc, Tm, and Ty are set to Tc = cLow, Tm = mLlow, and Ty = yLow. When the process proceeds to step S3104, the color determination thresholds Tc, Tm, and Ty are set to Tc = cHigh, Tm = mHigh, and Ty = yHigh, and in any case, the process proceeds to step S3105.
[0044]
Here, cLow, mLLow, yLow, cHigh, mHigh, and yHigh have a relatively low concentration value in the value range of 0 to 255, for example, a “value less than 16”.
cLow <cHigh
mLow <mHigh
yLow <yHigh
Is a constant that holds.
[0045]
In other words, the reason why the threshold value in the case of the gray compensation profile is increased is that the existence of the gray compensation profile originally has a high possibility of being intended to be recorded in gray, so that the color is processed by the process described later. It is for making it difficult to be determined. In other words, if there is no gray compensation profile, it can be said that a condition that makes it easy to determine that the image is a color is set. The gray compensation profile may be set in the host computer when a print job is issued, by a user's instruction, during the job, or may be set in advance on the operation panel of the image forming apparatus. good.
[0046]
When the process advances to step S3105, it is determined whether the object whose color is to be determined is an attribute of an image (halftone image). If it is determined that the object has the halftone image attribute, the process proceeds to step S3106. Otherwise, that is, if it is determined that the object of interest is graphics or characters, the process proceeds to step S3109.
[0047]
Step S3106 is a process between step S3108 and constitutes a loop control applied to all the pixels of the object of interest (halftone image area). When the processing of all the pixels is completed, the process proceeds to step S311. During the loop control, in step S3107, it is determined whether or not C> Tc, M> Tm, or Y> Ty is satisfied for the color values C, M, and Y of each pixel in the image data. , And the process advances to step S3110. If No, the loop control is continued.
[0048]
In step S3109, since the object of interest is graphics or characters, whether C> Tc, M> Tm, or Y> Yy holds for the color values C, M, and Y to be used. If it is determined, the process proceeds to step S3110 if Yes, and proceeds to step S3111 if No.
[0049]
In step S3111, it is determined whether color determination has been performed for all objects in the page. If No, the process advances to step S3113 to determine that the current page is color undetermined (determining) and ends. If Yes, the flow advances to step S3112 to determine that the current page is monochrome, and the processing ends. In step S3110, the current page is determined to be color, and the process ends.
[0050]
The determination result of the color page or the monochrome page is stored as an external variable in the RAM 2002 of FIG. 3, and as described with reference to FIG. 7, whether only the K plane in the bit map of the CMYK plane generated by the render 3002 is used, Or, the Print Manager 1526 refers to determine whether to use the bitmap of each plane of CMYK.
[0051]
When it is determined that only the K plane is used, high-speed printing is performed by printing black bitmap image data using black toner or black ink. Further, when four planes of CMYK are used, color printing of high image quality is performed although it takes more time than K single color.
[0052]
The reason why the recording speed of black single color is high is, for example, in the case of a laser beam printer, a photosensitive drum commonly used for each recording color component, and a toner of each recording color component abutting on the photosensitive drum. And a transfer device for transferring a toner image generated on the photosensitive drum, and a single exposure for K color. While image formation is completed by scanning and transfer to a transfer drum, in the case of full color, a device that performs a total of four scanning exposures and transfer to a transfer drum is used. Also, in a printer structure of a type that ejects ink droplets, a type in which the number of black nozzles is larger than that of C, M, and Y is used. As a result, the width that can be recorded by one scanning movement of the carriage becomes wider in the case of black monochrome, and the number of scanning movements can be reduced.
[0053]
<Second embodiment>
In the above-described embodiment (first embodiment), the threshold for color determination is switched between High and Low based on whether the output profile is the gray compensation profile or not. It is also possible to provide a screen for setting CMY, and perform color determination according to the values set on the screen. More detailed adjustment of the color determination threshold value is possible, and usability is improved. The content set by the user is stored and held in the HDD 2004, which is a nonvolatile memory, so that the previous setting content is reflected unless a change is made. This is referred to as a second embodiment.
[0054]
As described above, according to the present embodiment, a page is determined to be color only when a CMY output value equal to or greater than a certain value is detected even for one of the elements constituting the page, and the page is not detected at all. In this case, by providing a discriminating mechanism for discriminating monochrome, color judgment can be performed without omission. Even if a CMYK plate is created irrespective of the discrimination result, and printing is performed using the K plate only when the image is determined to be monochrome, if the CMY value for color judgment is a small value, the ignored CMY value is K It has little effect on plate generation and has little effect on print quality during monochrome output. Since the mask is not masked with the low-level CMY values in advance, the print quality of the highlight portion of the gradation at the time of color output is not affected. In addition, since the page interpretation method such as color processing is not changed according to the color determination result, page interpretation and color determination can be performed at the same time, processing can be performed in one pass, and there is no major performance problem. Furthermore, when gray compensation is selected by specifying color management, the possibility of erroneous determination can be further reduced by increasing the CMY value for determining color, and the user can selectively change the determination level. Can be.
[0055]
The present invention may be applied to a system including a plurality of devices including a printer (for example, a host computer, an interface device, a scanner, a printer, etc.), or may be applied to a single printer device.
[0056]
Further, as described in the above embodiment, in the image forming apparatus 200 of the present embodiment (the same applies to the image forming apparatuses 220 and 230), the system program stored in the HDD is loaded into the RAM 2003 and executed at the time of startup. Obviously, the invention also includes computer programs. Generally, in order to operate a computer program, a computer-readable storage medium such as a CD-ROM is set in the apparatus and copied or installed in the system. Obviously, media is also included in that category. If a means for reading data from the computer-readable storage medium (for example, a CD-ROM drive) is not provided in the image forming apparatus 200, the data is read by the same means of the host computer, transferred to the image forming apparatus 200, and stored in a program. Should be updated.
[0057]
When the computer executes the readout program codes, not only the functions of the above-described embodiments are realized, but also an operating system (OS) running on the computer based on the instructions of the program codes. It goes without saying that a part or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing.
[0058]
Further, after the program code read from the storage medium is written into a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that the CPU or the like provided in the card or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.
[0059]
Therefore, the following is a list of embodiments according to the present invention.
[0060]
[Embodiment 1] Generating means for generating bitmap image data of each recording color component based on print data described in a page description language, and a color image on a predetermined recording medium based on the generated bitmap image data A control method of an image forming apparatus that prints by a printing unit,
A search step of sequentially searching, for each object described in the page description language, whether or not data relating to a recording color component exceeds a predetermined threshold value;
If it is determined during the search process that there is an object having a recording color component exceeding the threshold value, the subsequent search is stopped, and a first determination step is performed to determine that the page of interest is a color page;
A second determining step of determining that the page of interest is a monochrome page when all objects are equal to or less than the color component equal to or less than the threshold value by the search processing in the searching step;
If it is determined in the first determining step that the page is a color page, the printing is performed by the printing unit based on the bitmap image data of each recording color component generated by the generating unit, and the second determining unit performs printing. When it is determined that the page is a monochrome page, a control step of printing by the printing unit using only the black bitmap image data generated by the generation unit; and
A method for controlling an image forming apparatus, comprising:
[0061]
[Embodiment 2] The object has a halftone image, graphics, and a character type, and the search unit sets the drawing color for graphics and characters to a pixel-by-pixel color for the halftone image. The control method of the image forming apparatus according to the first embodiment, wherein it is determined whether or not a threshold value is exceeded.
[0062]
[Embodiment 3] Further, a determination step of determining whether or not color management for performing gray compensation is specified during a print job;
Setting the threshold value according to the determining step;
The control method for an image forming apparatus according to the first or second embodiment, further comprising:
[0063]
[Embodiment 4] The threshold according to Embodiment 3, wherein a threshold when it is determined in the determination step that color management for performing gray compensation is designated is larger than a threshold when no color management exists. A method for controlling an image forming apparatus.
[0064]
[Embodiment 5] The control method of an image forming apparatus according to Embodiment 1 or 2, further comprising a step of setting the threshold value by an input from a predetermined operation unit.
[0065]
[Embodiment 6] The image processing apparatus further includes a color management step of converting a color space represented by the print data into a color space of the printing unit. The control method for an image forming apparatus according to any one of the first to fifth embodiments, wherein
[0066]
[Embodiment 7] Generating means for generating bitmap image data of each recording color component based on print data described in a page description language, and a color image on a predetermined recording medium based on the generated bitmap image data An image forming apparatus that prints the image by a printing unit,
A search unit for sequentially searching whether or not data on a recording color component exceeds a predetermined threshold value for each object described in the page description language;
During the search processing by the search means, when it is determined that there is an object having a recording color component exceeding the threshold value, the subsequent search is stopped, and the first determination means determines that the page of interest is a color page;
A second determination unit configured to determine that the page of interest is a monochrome page when all the objects are equal to or smaller than the color component equal to or smaller than the threshold value by the search processing by the search unit;
If the first determination unit determines that the page is a color page, the printing unit prints based on the bitmap image data of each recording color component generated by the generation unit, and the second determination unit When it is determined that the page is a monochrome page, control means for printing by the printing means using only the black bitmap image data generated by the generating means,
An image forming apparatus comprising:
[0067]
[Embodiment 8] A generating means for generating bitmap image data of each recording color component based on print data described in a page description language, and a color image on a predetermined recording medium based on the generated bitmap image data A computer program that functions as an image forming apparatus that prints
A search unit for sequentially searching whether or not data on a recording color component exceeds a predetermined threshold value for each object described in the page description language;
During the search processing by the search means, when it is determined that there is an object having a recording color component exceeding the threshold value, the subsequent search is stopped, and the first determination means determines that the page of interest is a color page;
A second determination unit configured to determine that the page of interest is a monochrome page when all the objects are equal to or smaller than the color component equal to or smaller than the threshold value by the search processing by the search unit;
If the first determination unit determines that the page is a color page, the printing unit prints based on the bitmap image data of each recording color component generated by the generation unit, and the second determination unit When it is determined that the page is a monochrome page, control means for printing by the printing means using only the black bitmap image data generated by the generating means,
A computer program for an image forming apparatus, which functions as a computer.
[0068]
[Embodiment 9] A computer-readable storage medium storing the computer program according to Embodiment 8.
[0069]
In the above embodiment, the configuration according to the second to sixth embodiments may be added to the image forming apparatus, the computer program, and the computer readable storage medium.
[0070]
【The invention's effect】
As described above, according to the present invention, it is possible to determine with high accuracy whether color or monochrome in order to improve the throughput of print processing.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an overall configuration of an image forming system according to an embodiment.
FIG. 2 is a software block diagram of the image forming apparatus according to the embodiment.
FIG. 3 is a block diagram illustrating a configuration of a control unit of the image forming apparatus according to the exemplary embodiment.
FIG. 4 is an external view of an input / output device of the image forming apparatus according to the embodiment.
FIG. 5 is an external view of an operation unit of the image forming apparatus according to the embodiment.
FIG. 6 is a block diagram illustrating a configuration near an operation unit and a CPU of the image forming apparatus according to the exemplary embodiment.
FIG. 7 is a schematic configuration diagram of a data flow in the embodiment.
FIG. 8 is a flowchart illustrating a color determination processing procedure according to the embodiment.

Claims (1)

Generating means for generating bitmap image data of each recording color component based on print data described in a page description language, and printing a color image on a predetermined recording medium based on the generated bitmap image data by the printing means A method for controlling an image forming apparatus, comprising:
A search step of sequentially searching, for each object described in the page description language, whether or not data relating to a recording color component exceeds a predetermined threshold value;
If it is determined during the search process that there is an object having a recording color component exceeding the threshold value, the subsequent search is stopped, and a first determination step is performed to determine that the page of interest is a color page;
A second determining step of determining that the page of interest is a monochrome page when all objects are equal to or less than the color component equal to or less than the threshold value by the search processing in the searching step;
When it is determined in the first determination step that the page is a color page, the printing is performed by the printing unit based on the bitmap image data of each recording color component generated by the generation unit, and the second determination unit performs the printing. A control step of causing the printing means to print using only the black bitmap image data generated by the generating means when the image forming apparatus determines that the page is a monochrome page. Control method.

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