JP2008301414A - Image processor, image forming apparatus and image processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processor capable of outputting image data due to gray compensation processing closer to a requirement in entering even when processing such as RGB correction or ink simulation internally converting a color space of an input object is performed. <P>SOLUTION: The image processor includes a decision means for making a gray decision for input image data; a gray compensation processing means which performs gray compensation for performing color processing on the image data into a single color of black when an input color of the image data is decided as gray by the decision means, or which does not perform the gray compensation when the input color of the image data is judged as any color other than gray by the judgment means; and a conversion means for converting a color space of the image data processed by the gray compensation processing means into another color space. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image processing apparatus, an image forming apparatus, and an image processing method, and more particularly to a technique that is preferably applied when performing both color space conversion processing such as RGB correction and ink simulation and gray compensation processing. is there.

Conventionally, laser printers generally perform color printing in four color spaces of CMYK. For the color printing, the input color space includes RGB and CMYK. In addition, data (PDL data) transferred from a PC or the like at the time of printing usually has color information for each object (text / graphic / image / line drawing, etc.). Here, when the object is in the RGB color space, it is converted into the CMYK color space using some conversion formula, but the following conversion formula is used as a general formula.
C = (1-RK) / (1-K)
M = (1-G−K) / (1-K)
Y = (1-BK) / (1-K)
K = min (1-R, 1-G, 1-B)
In this case, when R = G = B, it is possible to represent only in black, and in this case, it is possible to directly convert only the K component, not to CMYK. Even in the case where the object is in the CMYK color space, it can be expressed in black similarly when C = M = Y. This technique is known by the name Gray compensation.

  By the way, input data relating to drawing is generally managed in units called objects such as text, images, graphics, and the like. This object also includes settings for color space specification, drawing color specification, gray compensation settings, and various correction processes. Here, with reference to FIG. 6, how the gray compensation process is performed on the data designated in the RGB color space will be described. As one method, there is a method of designating whether or not to perform gray compensation for each object type. This designation is performed in the input data or by setting from an external input device such as an operation panel.

  In the example of FIG. 6, gray compensation is performed for text and images, and gray compensation is not performed for graphics. For example, when the color of the input text is R = G = B, since gray compensation is effective for the text, gray compensation is performed, and the output data is converted so as to express gray only by the K component. On the other hand, for example, when the color of the graphic is R = G = B, gray compensation is disabled, so gray compensation is not performed, and output data is output by expressing gray with four components of CMYK. As for the image, gray compensation is set to be effective, but since the drawing color is not R = G = B, gray compensation is not performed, and data is converted into four components of CMYK as usual and data is output. .

  On the other hand, besides the gray compensation described above, several methods for internally changing the input color are known. The first is a method of changing the RGB color space to the CMYK color space. Since there are several standards with different reproduction regions such as sRGB and AdobeRGB for the RGB color space, there is a function (RGB correction) for changing to the CMYK color space by a conversion method according to the standard. Second, even in the CMYK color space, in order to convert the output result to a form close to that of another output device with different toner or ink (generally referred to as ink simulation), the original CMYK color space is changed to another type. This is a method of converting to the CMYK color space.

For example, in Japanese Patent Application Laid-Open No. H11-228707, setting means for setting, based on a manual instruction, gray compensation processing for setting an image forming apparatus to form an image on a recording medium in a single black color when the input color is gray based on a request, and gray compensation An image processing apparatus is disclosed that performs color processing (image formation with a plurality of colors) similar to input image data indicating colors other than gray when processing is not set.
JP-A-9-270928

  In the image processing apparatus disclosed in Patent Document 1, when there is a process for converting an input color into another color space internally, there is no description as to when the gray compensation process is performed. Therefore, for example, a method of performing gray compensation processing in the CMYK color space after performing the above-described RG correction processing is also conceivable. FIG. 7 shows a color processing path when the above procedure is performed.

In FIG. 7, the input color space is displayed as four examples for easy understanding. Originally, input color space, RGB correction, and ink simulation are specified separately.
RGB: Normal RGB color space RGB correction: RGB color space in which RGB correction processing is entered (hereinafter referred to as R'G'B 'color space)
CMYK: Normal CMYK color space CMYK ink: CMYK color space for ink simulation processing (hereinafter referred to as C'M'Y'K 'color space)

The description of each process in FIG. 2 is as follows.
RGB to CMYK process: A process for converting the input color of the RGB color space to the CMYK color space. The conversion formula is the conversion formula described above. R'G'B 'to RGB process: RGB correction is specified Processing for converting an input image in the RGB color space into the RGB color space using a specified correction method: C'M'Y'K 'to CMYK processing: input image in the CMYK color space in which ink simulation is specified For the input color, a process for converting the input color into the CMYK color space using the conversion formula for the specified ink model: Gray compensation process: When the input color is gray (C = M = Y in the example of FIG. 7), black Output in single color, otherwise output in CMYK 4 colors / color processing (γ conversion, gradation correction, etc.): Color for the color space (CMYK color space in this case) that is finally passed to the output device Change the taste Cormorants processing

  In FIG. 7, it is assumed that the input color is gray in each case. First, in the case of CMYK, the case of C = M = Y is gray. Since no conversion is applied to the input color until the gray compensation process, the input during the gray compensation process remains C = M = Y. For this reason, when the input color is gray, the gray compensation process is performed as it is, and a single black color is output. On the other hand, when the input color is not gray, the gray compensation process is not performed and the output is in four colors of CMYK. Next, in the case of RGB, the case of R = G = B is gray. RGB to CMYK processing is performed on this input color. According to the above conversion equation, when R = G = B, C = M = Y even after conversion, and therefore the gray compensation process is performed only when the input color is gray.

  On the other hand, in the case of RGB correction and CMYK ink, the above does not occur. First, in the case of CMYK ink, the CMYK ink is converted into the CMYK color space using a conversion formula for a predetermined ink model. In this equation, when C ′ = M ′ = Y ′, the value after conversion is not always C = M = Y. Similarly, even if C ′ = M ′ = Y ′, the converted value may be C = M = Y. Accordingly, there is a possibility that the gray compensation process is not performed even when the input color is gray, or the gray compensation process is performed even when the input color is not gray. In the case of RGB correction, in RGB correction, the input color is converted using a predetermined conversion formula for RBG correction in the first R′G′B ′ to RGB processing. Also in this process, when R ′ = G ′ = B ′, the value after conversion is not necessarily R = G = B, and when R = G = B, the value after RGB to CMYK processing Is not necessarily C = M = Y. Therefore, a phenomenon similar to that of the above-described CMYK ink occurs.

  As described above, when color space conversion processing is performed before gray compensation processing, gray compensation may not occur even when the input color is gray, and this reflects processing originally desired for gray compensation processing. It will not be.

  Therefore, in view of the above circumstances, the present invention has a form close to the request at the time of input even when processing for internally converting the color space of the input object such as RGB correction and ink simulation is performed. It is an object of the present invention to provide an image processing apparatus capable of outputting image data by gray compensation processing.

  In order to achieve such an object, the present invention provides a determination unit that performs gray determination of input image data, and when the determination unit determines that the input color of the image data is gray, the image data is converted to black. Performs gray compensation for color processing, and if the determination means determines that the input color of the image data is other than gray, the gray compensation processing means that does not perform gray compensation, and the color of the image data after processing by the gray compensation processing means An image processing apparatus comprising: conversion means for converting a space into another color space.

  Further, the present invention is characterized in that, in the above image processing apparatus, the conversion means converts the color space of the image data into another color space for the image data that is not subjected to gray compensation by the gray compensation means. It may be a thing.

  In the image processing apparatus according to the present invention, the conversion unit may perform correction processing of the RGB color space.

  In the image processing apparatus according to the present invention, the conversion unit may perform ink simulation processing in a CMYK color space.

  In the image processing apparatus according to the present invention, the processing by the gray compensation unit and the processing by the conversion unit may be performed based on setting contents designated for each image.

  In the image processing apparatus according to the present invention, the setting content may be specified by an external input device that inputs operation content of the device.

  In the image processing apparatus, the setting content may be included in input image data.

  As another aspect, the present invention is an image forming apparatus including the above-described image processing apparatus.

  As another aspect, the present invention provides a determination step for performing gray determination of input image data, and when the input color of the image data is determined to be gray by the determination step, the image data is color-processed into a single black color. When gray compensation is performed and the input color of the image data is determined to be other than gray by the judgment step, the color compensation processing step without gray compensation and the color space of the image data after processing by the gray compensation processing step are separated. And a conversion step for converting to a color space.

  According to the present invention, even when processing for internally converting the color space of an input object, such as RGB correction or ink simulation, is performed, an image obtained by gray compensation processing in a form close to what is desired at the time of input. An image processing apparatus capable of outputting data is provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Embodiment 1]
An image processing apparatus will be described as a first embodiment of the present invention. FIG. 1 is a block diagram illustrating a hardware configuration of the image processing apparatus according to the present embodiment. The image processing apparatus 10 according to this embodiment includes a network I / F (Interface) 11, a control unit 12, a main storage unit 13, an auxiliary storage unit 14, an external storage I / F 15, and a system bus 16.

  The network I / F 11 is a hardware interface for bidirectional data communication with communication devices on a network such as a LAN (Local Area Network), a public line, and a wireless line.

  The control unit 12 is a control circuit including a CPU (Central Processing Unit) and controls the image processing apparatus 10. Therefore, in the control unit 12, an OS (Operating System) that is basic software for controlling the image processing apparatus 10 operates. Further, the control unit 12 executes image processing from PDL syntax analysis (parsing) processing (input data interpretation processing) to rendering processing (page rendering processing) of the image processing apparatus 10. Therefore, the control unit 12 executes instructions of various programs and arithmetic processing in order to realize an image processing function executed on the OS.

  The main storage unit 13 includes a ROM (Read Only Memory) and a RAM (Random Access Memory). The ROM is a storage circuit that stores an OS that operates in the control unit 12, various programs for realizing the image processing function of the image processing apparatus 10, and data used in the program. The RAM is stored in the ROM. The storage circuit temporarily expands (loads) the program and data used in the program, and temporarily stores the expanded (load) program and data. In addition, the RAM includes a display list (intermediate data) after PDL syntax analysis (interpretation of input data) and a display list (intermediate data) for input data by various programs of image processing functions executed by the control unit 12. ) Is temporarily stored as a bitmap image (raster image).

  The auxiliary storage unit 14 is a storage device such as an HDD (Hard Disk Drive) in which data used by various programs for realizing the image processing function of the image processing apparatus 10 is stored.

  The external storage I / F 15 is used for data transmission between the external storage unit 18 such as a memory card represented by an SD card (Secure Digital memory card) and CF (CompactFlash (registered trademark)) and the image processing apparatus. Hardware interface.

  The system bus 16 is a transmission circuit that connects the network I / F 11, the control unit 12, the main storage unit 13, the auxiliary storage unit 14, and the external storage I / F 15. The system bus 16 transmits a control command signal from the control unit 12 to the peripheral network I / F 11, the main storage unit 13, the auxiliary storage unit 14, and the external storage I / F 15. The system bus 16 transmits data signals from the network I / F 11, the main storage unit 13, the auxiliary storage unit 14, and the external storage I / F 15 to the control unit 12.

  As described above, in the image processing apparatus 10, the control unit 12 develops (loads) various programs and data stored in the ROM of the main storage unit 13 onto the RAM of the main storage unit 13. By executing the above, the overall operation of the image processing apparatus 10 including the peripheral network I / F 11, the main storage unit 13, the auxiliary storage unit 14, and the external storage I / F 15 is controlled via the system bus 16. The image processing function of the image processing apparatus 10 included in the processing apparatus 10 is realized from the PDL parsing process to the drawing process.

  FIG. 2 is a block diagram illustrating a functional configuration of the image processing apparatus according to the present embodiment.

  The image processing apparatus 30 according to the present embodiment includes a data reception unit 31, a PDL interpretation unit 32, a color processing unit 33, a drawing processing unit 34, and an output device conversion unit 35 as functional configurations.

  Information relating to printing is transmitted from the data input means 20 such as a printer driver to the data receiving unit 31 of the image output apparatus 30. These data are called PDL. Data is converted from a print command to raster data by the PDL interpretation unit 32. In the process of converting this data, the color processing unit 33 changes the color space, adjusts the hue, and the like. The input drawing-related data is managed in units called objects such as text, images, and graphics. Each of the objects includes a color space designation, a drawing color designation, a gray compensation setting, and various correction processing settings. Note that settings such as gray compensation are not necessarily included in the data, and may be realized by input to an external input device such as an operation panel. These data are converted as designated by the color processing unit 33 and written into a memory or the like through the drawing processing unit 34. The converted data is output to the output device 40 through the output device conversion means 35.

  FIG. 3 is a diagram showing a processing path related to the color conversion function in the present embodiment. The definitions of the four color spaces and the respective processes are the same as those described in FIG. 7, except that the gray compensation process is performed before the color conversion process.

  First, when the color space is RGB, when R = G = B, it is determined that the input color is gray, output is performed in a single black color by gray compensation processing, and predetermined color conversion is performed (in the figure, gray compensation processing is performed). Go to the K-colored arrow through the bottom arrow). On the other hand, when R = G = B is not satisfied, the input color is not gray. Therefore, the output is not performed in a single black color in the gray correction process, but is converted into the CMYK color space by the RGB to CMYK process, and a predetermined color conversion is performed. (In the figure, the gray process advances to the RGB and CMYK arrows through the upper arrow).

  When the color space is RGB correction, when R = G = B, the input color is determined to be gray, output in a single black color is performed in gray compensation processing, and predetermined color conversion is performed (from the gray compensation processing in the figure). Go through the arrow below to the K arrow.) On the other hand, when R = G = B is not satisfied, the input color is not gray. Therefore, the output is not performed in a single black color by the gray correction process, and is converted to the RGB color space by the R′G′B ′ to RGB process. The RGB color space is converted into a CMYK color space by RGB to CMYK processing, and predetermined color conversion is performed (in the figure, the gray processing is advanced to the RGB correction, RGB, and CMYK arrows through the upper arrow).

  When the color space is CMYK, when R = G = B, the input color is determined to be gray, and output is performed in a single black color by the gray compensation process, and predetermined color conversion is performed (in the figure, from the gray compensation process). Go to the K-colored arrow through the arrow). On the other hand, when R = G = B is not satisfied, the input color is not gray, so that the black color is not output in the gray correction process, and a predetermined color conversion is performed for the input color (in the figure, the arrow above the gray process) Through to the CMYK arrow).

  When the color space is CMYK ink, when R = G = B, it is determined that the input color is gray, the output is performed in a single black color by the gray compensation process, and predetermined color conversion is performed (from the gray compensation process in the figure). Go through the arrow below to the K arrow.) On the other hand, when R = G = B is not satisfied, the input color is not gray, so the output is not performed in black by the gray correction process, and is converted to the CMYK color space by the C′M′Y′K ′ to CMYK process. Then, predetermined color conversion is performed (in the figure, the process proceeds from the gray process to the CMYK ink and CMYK arrows through the upper arrow).

  As described above, by performing the gray compensation process before the color conversion process, the gray compensation can be surely performed when the input color is gray, and the image that is not subjected to the gray compensation or the gray compensation is not performed. In the case of setting, color space conversion processing corresponding to each color space is performed without changing the input color.

  FIG. 4 is a flowchart showing the flow of gray compensation processing and color conversion processing in the present embodiment. This flow shows the procedure of gray compensation processing and color conversion processing for an image for one page output in this embodiment, and actually there are various processes related to image output before and after this processing. To do.

  First, an object to be processed is selected (step S101). There are one or more objects on the page. Since it is necessary to perform the processing from now on for each object, an object that has not yet been processed is selected in this step.

  Subsequently, the input color space of the selected object is examined, and processing corresponding to the color space is performed (step S102). Here, the RGB color space and the CMYK color space are given as examples, but the color space to which the present invention is applied may be another color space such as HSB or CIE color system.

  Hereinafter, processing according to the RGB color space will be described. If the input color space of the selected object is RGB (step S102 / RGB), it is confirmed whether the gray compensation setting for the object is ON (step S103). This gray compensation setting information is given by the gray compensation setting for each object (mainly for each object type) from the external input device such as the operation panel or the gray compensation setting set for each object in the data. ing.

  If the gray compensation setting is ON (step S103 / YES), gray determination is performed on the selected object in the RGB color space (step S104). When the object is a target of gray compensation, that is, when the input color of the object is R = G = B (step S104 / YES), the object is converted into a black monochrome expression by gray compensation processing (step S105). On the other hand, when the object is not the target of gray compensation (step S104 / NO), the following processing is performed as in the case where the gray compensation setting is OFF.

  If the gray compensation setting is OFF (step S103 / NO), it is confirmed whether the selected object is an object of RGB correction, that is, whether the RGB correction setting is ON (step S106). If the RGB correction setting is ON (step S106 / YES), RGB correction processing is performed based on a predetermined RGB correction method, and the R′G′B ′ color space of the input color is converted to the RGB color space (step S107). ). Then, the RGB to CMYK conversion process is performed on the selected object using the conversion formula described above (step S108). On the other hand, when the RGB correction setting is OFF (step S106 / NO), the RGB to CMYK conversion process is performed without performing the RGB correction process (step S108).

  Next, processing according to the CMYK color space will be described. When the input color space of the selected object is CMYK (step S102 / CMYK), it is confirmed whether the gray compensation setting for the object is ON (step S112). The information regarding the gray compensation setting is the same as that described in the processing corresponding to the RGB color space.

  When the gray compensation setting is ON (step S109 / YES), gray determination is performed on the selected object in the CMYK color space (step S110). When the object is a target of gray compensation, that is, when the input color of the object is C = M = Y (step S110 / YES), the object is converted into a black single color representation by gray compensation processing (step S111). On the other hand, when the object is not the target of gray compensation (step S110 / NO), the same processing as the case where the gray compensation setting is OFF is performed as follows.

  When the gray compensation setting is OFF (step S109 / NO), it is confirmed whether the selected object is a target of ink simulation, that is, whether the ink simulation setting is ON (step S112). If the ink simulation setting is ON (step S112 / YES), ink simulation processing is performed based on a predetermined ink model, and the C′M′Y′K ′ color space of the input color is converted into the CMYK color space (step S112). S113). On the other hand, when the ink simulation setting is OFF (step S112 / NO), the ink simulation process is not performed.

  After the above processing is completed, it is confirmed whether processing has been performed for all objects (step S114). If there is an unprocessed object (NO in step S114), the process returns to the selection of the object to be processed (S101), and the same process as described above is performed on the unprocessed object. When the above processing is completed for all objects in the page (step S114 / YES), the remaining color processing is performed for each page (step S115). This color processing is performed on the output color space, and includes γ conversion processing and gradation correction processing.

  According to the present embodiment, since gray compensation processing is performed before the internal color conversion processing, gray determination can be performed on the input color, which is the purpose of gray compensation, “when the input color is gray. Can be processed according to the request of “outputting the output to black in a single color”. Also, gray compensation and color conversion processing such as RGB correction processing and ink simulation processing can be used together, and when gray compensation processing and color conversion processing are used together, the gray compensation processing becomes closer to what is desired. .

[Embodiment 2]
An image forming apparatus will be described as a second embodiment of the present invention. The image forming apparatus according to the present embodiment has the image processing apparatus according to the first embodiment mounted therein. FIG. 1 is a diagram illustrating a schematic configuration of an image processing apparatus according to the present embodiment.

  The image forming apparatus according to the present embodiment includes an ADF (Auto Document Feeder) 101, a contact glass 106, a first tray 108, a second tray 109, a third tray 110, a first paper feeding unit 111, 2 paper feed unit 112, 3rd paper feed unit 113, vertical transport unit 114, photoconductor 115, transport belt 116, fixing unit 117, paper discharge unit 118, development unit 120, and reading unit 130. A writing unit 140, a finisher 150, a double-sided paper feeding unit 161, and a branching claw 162.

  An ADF (Auto Document Feeder) 101 includes a document table 102, a paper feed roller 103, a feed belt 104, a delivery roller 105, and a document set detection unit 107. Further, the finisher 150 includes a switching plate 151, a normal discharge roller 152, transport rollers 153 and 155, a normal discharge tray 154, a stapler 156, a discharge roller 157, a staple table 158, a jogger 159, and a staple completion discharge tray 160. Composed.

  The reading unit 130 includes an exposure lamp 131, a first mirror 132, a lens 133, a CCD image sensor 134, a second mirror 135, and a third mirror 136. The writing unit 140 includes a laser output unit 141, an imaging lens 142, and a mirror 143. The image processing apparatus according to the first embodiment having a hardware configuration as shown in FIG. 1 is connected to the reading unit 130 and the writing unit 140 via an internal bus in the image forming apparatus according to the present embodiment, and is used for image data and control signals. We are communicating.

  An image forming processing operation in the image forming apparatus of the present embodiment will be described.

  A document stack placed on the document table 102 of the ADF 101 with the image surface of the document facing upward is pressed from the top document to the feed roller 103 and the feed roller by pressing the start key on the operation unit. The sheet is fed to a predetermined position on the contact glass 106 by the feeding belt 104.

  The document fed to a predetermined position on the contact glass 106 is read by the reading unit 130, and the document that has been read is discharged via the feeding belt 104 and the discharge roller 105. Further, when the document set detection unit 107 detects that the next document is on the document table 102, it is fed onto the contact glass 106 in the same manner as the processing operation described above. The feeding roller 103, the feeding belt 104, and the discharging roller 105 are driven by a conveyance motor (not shown).

  The recording sheets stacked on the first tray 108, the second tray 109, and the third tray 110 are fed by the first paper feeding device 111, the second paper feeding device 112, and the third paper feeding device 113, respectively, and are conveyed vertically. The unit 114 is transported to a position where it abuts on the photoreceptor 115.

  The image data read by the reading unit 130 is written on the photoconductor 115 by the laser from the writing unit 140, and an electrostatic latent image is formed on the photoconductor 115. Then, the electrostatic latent image is developed by passing through the developing unit 120, and a toner image is formed on the photoreceptor 115.

  The recording paper transported from the vertical transport unit 114 is transported by a transport belt 116 having the same rotational speed as that of the photosensitive member 115. At this time, the toner image formed on the photosensitive member 115 is transferred onto the recording paper. . It is conveyed to the fixing unit 117.

  The recording sheet on which the toner image is transferred is conveyed to the fixing unit 117. In the fixing unit 117, the toner image transferred onto the recording paper is thermally fixed.

  Note that the photoconductor 115, the conveyance belt 116, the fixing unit 117, the paper discharge unit 118, and the development unit 120 are driven by a main motor (not shown). Each of the paper feeding apparatuses 111 to 113 is driven by a paper feeding clutch (not shown) that transmits the driving of the main motor. Further, the vertical conveyance unit 114 is driven by transmission of a main motor driven by an intermediate clutch (not shown).

  The paper discharge unit 118 discharges the recording paper to the finisher 150 that is a post-processing device.

  The finisher 150 is a device for guiding the recording paper to the normal paper discharge tray 154 side and the staple table 158 side. When the switching plate 151 is switched upward, the recording paper is discharged to the normal paper discharge tray 154 side via the transport roller 153. Conversely, when the switching plate 151 is switched downward, the recording paper is conveyed to the staple table 158 via the conveying roller 155 and the paper discharge roller 157.

  The normal paper discharge tray 154 is a paper discharge tray that can move back and forth, and sorts the recording paper (copy paper) that moves forward and backward and is simply discharged. As a result, the recording paper conveyed to the normal paper discharge tray 154 is sorted for each original or each copy unit sorted by the image memory.

  On the other hand, every time a sheet of recording paper loaded on the staple table 158 is discharged, the paper end face is aligned by the paper aligning jogger 159, and is bound by the stapler 156 when a part of the copy is completed. The recording paper group bound by the stapler 156 is stored in the staple completion paper discharge tray 160 by its own weight.

  When images are formed on both sides of the recording paper, the branching claw 162 for switching the path is set on the upper side. When the branching claw 162 is set on the upper side, the recording paper on which an image is formed on one side of the recording paper is temporarily stored in the double-sided paper feeding unit 161 without being conveyed to the discharge tray 154 side. Then, the recording paper once stocked in the double-sided paper feeding unit 161 is fed again, and the toner image formed on the photosensitive member 115 is transferred again. After the double-sided transfer, the branching claw 162 for switching the path is set on the lower side, and the recording paper subjected to the double-sided printing is guided to the finisher 150. In this way, images are formed on both sides of the recording paper.

  The above-described embodiment is a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiment alone, and various modifications are made without departing from the gist of the present invention. Implementation is possible.

  That is, the image processing apparatus in the above-described embodiment operates by processing, means, and functions executed by a computer (CPU) according to program instructions. The program sends a command to each component of the computer, and performs gray compensation in a predetermined process and function as described above, for example, before the process such as color space conversion and hue adjustment by the color processing unit 33. Gray determination and gray compensation processing are performed according to the setting contents. Specifically, after identifying the input color space, the gray compensation setting of the selected object is confirmed, and gray determination is performed in the identified color space (RGB or CMYK) when the setting content is ON. In such a case, a gray compensation process for converting the object into a single black color is performed. When the processing is completed for all objects, color processing such as γ conversion processing and gradation correction processing is performed on the page. As described above, the processes and means in the above-described embodiment are realized by specific means in which the program and the computer cooperate.

  Then, for example, a computer (CPU) of the image processing apparatus stores the program code stored in the storage medium via a computer-readable recording medium that records the program code of the software that realizes the functions of the above-described embodiments, that is, the storage medium. The object of the present invention is also achieved by executing the reading. Further, the program can be loaded and executed directly on a computer through a communication line without going through a recording medium, and the object of the present invention can be achieved similarly.

  In this case, the program code itself read from the storage medium or loaded and executed through the communication line realizes the functions of the above-described embodiment. And the storage medium which memorize | stored the program code comprises this invention.

  Examples of the storage medium for supplying the program code include a floppy (registered trademark) disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a nonvolatile memory card, a ROM, and a magnetic tape. Can be used.

1 is a block diagram illustrating a hardware configuration of an image processing apparatus according to an embodiment of the present invention. 1 is a block diagram illustrating a functional configuration of an image processing apparatus according to an embodiment of the present invention. It is the figure which showed the path | pass of the process regarding the color conversion function in embodiment of this invention. It is the flowchart which showed the flow of the gray compensation process and color conversion process in embodiment of this invention. 1 is a diagram illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention. It is a figure for demonstrating the outline | summary of a gray compensation process. It is the figure which showed the path | pass of the process regarding a color conversion function (when performing gray compensation processing after color space conversion processing).

Explanation of symbols

10, 30 Image processing device 11 Network I / F
12 Control unit (CPU)
13 Main memory (ROM, RAM)
14 Auxiliary storage (HDD)
15 External storage I / F
16 System bus 18 External storage (SD, CF)
DESCRIPTION OF SYMBOLS 20 Data input means 31 Data receiving part 32 PDL interpretation part 33 Color processing part 34 Drawing process part 35 Output device conversion means 40 Output device

Claims (9)

A determination means for performing gray determination of the input image data;
When the determination unit determines that the input color of the image data is gray, gray compensation is performed so that the image data is processed into a single black color, and the determination unit determines that the input color of the image data is other than gray. If so, gray compensation processing means that does not perform the gray compensation;
Conversion means for converting the color space of the image data processed by the gray compensation processing means into another color space;
An image processing apparatus comprising:   The image processing apparatus according to claim 1, wherein the conversion unit converts a color space of the image data into another color space for the image data that is not subjected to the gray compensation by the gray compensation unit.   The image processing apparatus according to claim 1, wherein the conversion unit performs correction processing of an RGB color space.   The image processing apparatus according to claim 1, wherein the conversion unit performs ink simulation processing in a CMYK color space.   5. The image processing apparatus according to claim 1, wherein the processing by the gray compensation unit and the processing by the conversion unit are performed based on setting contents designated for each image. 6.   The image processing apparatus according to claim 5, wherein the setting content is designated by an external input device that inputs operation content of the device.   The image processing apparatus according to claim 5, wherein the setting content is included in input image data.   An image forming apparatus comprising the image processing apparatus according to claim 1. A determination step for performing gray determination of the input image data;
If the input color of the image data is determined to be gray by the determination step, gray compensation is performed so that the image data is processed into a single black color, and the input color of the image data is determined to be other than gray by the determination step. If so, a gray compensation processing step that does not perform the gray compensation;
A conversion step of converting the color space of the image data after the processing by the gray compensation processing step into another color space;
An image processing method comprising:

Images