This application is based on Japanese Patent Application No. 2013-087762 filed on Apr. 18, 2013, the contents of which are incorporated herein by reference.
1. Technical Field
The present invention relates to a print setting apparatus performing print setting of print data output by an image forming apparatus which can execute a plurality of calibration methods and a non-transitory computer readable recording medium stored with a control program of the print setting apparatus.
2. Description of Related Art
In markets of color management, several data sets formed by device values and color measurement values are distributed as industry standard colors. Examples of the industry standard colors include JapanColor2011, Fogra39, and GRACol (General Requirements for Applications in Commercial Offset Lithography) that conform to international standards of ISO (International Organization for Standardization). Also, profiles created based on such industry standard colors are also available in the markets.
In recent years, since color reproduction of grey has become important in the markets, grey calibration methods suitable for respective industry standard colors have been suggested. For example, G7 Calibration has been suggested as the grey calibration method suitable for GRACol by IDEAlliance (International Digital Enterprise Alliance). There are also several known grey calibrations developed uniquely by printer makers.
Correction methods by such grey calibrations are decided based on respective unique ideas. Therefore, when different grey calibrations are used, different correction results may be obtained. Accordingly, print systems configured to enable selecting one method from a plurality of grey calibration methods suitable for respective industry standard colors have been spread to meet requirements of users in various industries. As a result, a plurality of calibration methods are mixed in a single print system. Thus, for example, when a calibration method executed at the time of creation of a color profile for color conversion is not registered in a current printer, a problem occurs in that color reproduction accuracy desired by a user may not be obtained.
Accordingly, Japanese Unexamined Patent Application Publication No. 2012-178800 suggests a printer that performs setting adjustment of mechanical conditions of an apparatus, e g., a sheet feeding amount, temperature and wind power at the time of drying, and a head speed, according to a print result of a test pattern. Japanese Unexamined Patent Application Publication No. 2007-6208 suggests an output density adjustment system that displays warning information when calibration data defining a relation between an output density and a standard density of a printer satisfies a predetermined condition. Japanese Unexamined Patent Application Publication No. 2011-223620 suggests a print instruction terminal that acquires a plurality of profiles in which sheet type information at the time of output of a color chart is embedded, compares the sheet type information extracted from these profiles to sheet type information at the time of printing, and performs display so that one or the plurality of profiles extracted from the comparison result can be selected.
However, although the technologies suggested in the patent documents are used, the problem that color reproduction accuracy of an output image deteriorates still remains unresolved when a calibration method executed at the time of creation of a color profile is not registered in a current printer.
The invention is devised in view of the problems of the foregoing technologies of the related art and an object of the invention is to provide a print setting apparatus preventing color reproduction accuracy of an output image from deteriorating when a calibration method executed at the time of creation of a color profile for color conversion is not registered in an image forming apparatus and a non-transitory computer readable recording medium stored with a control program of the print setting apparatus.
To achieve at least one of the abovementioned objects, a print setting apparatus reflecting one aspect of the present invention, is applied to perform print setting of print data to be output by an image forming apparatus capable of executing a plurality of calibration methods, and includes a selection unit, a determination unit and a first notification unit. The selection unit selects one color profile as a color profile to be used for color conversion of the print data from a plurality of color profiles. The determination unit determines whether a first calibration method executed at a time of creation of one color profile selected by the selection unit agrees with a second calibration method currently registered in the image forming apparatus, with reference to the one color profile selected by the selection unit and a calibration table indicating a correspondence relation between output characteristic values of the image forming apparatus before and after correction by the second calibration method. The first notification unit notifies a user of a determination result by the determination unit.
It is preferable in the above print setting apparatus that the determination unit determines whether the first calibration method agrees with the second calibration method, by identifying the first calibration method based on identification information described in advance in the one color profile selected by the selection unit and identifying the second calibration method based on the calibration table.
It is preferable in the above print setting apparatus that the determination unit determines whether the first calibration method agrees with the second calibration method, by identifying the first calibration method based on a correspondence relation between a device value and a device-independent value shown in the one color profile selected by the selection unit and identifying the second calibration method based on the calibration table.
It is preferable that a retrieval unit that retrieves, among the plurality of color profiles, a color profile which is other color profile different from the one color profile selected by the selection unit and for which the first calibration method is executed at the time of creation of the other color profile, when it is determined that the first calibration method does not agree with the second calibration method, and a second notification unit that notifies the user of a retrieval result of the other color profile by the retrieval unit are further included in the above print setting apparatus.
It is preferable that an optimization unit that optimizes the calibration table in accordance with the first calibration method, when it is determined that the first calibration method does not agree with the second calibration method is further included in the above print setting apparatus.
To achieve at least one of the abovementioned objects, a non-transitory computer readable recording medium reflecting another aspect of the present invention, is stored with a control program of a print setting apparatus performing print setting of print data to be output by an image forming apparatus capable of executing a plurality of calibration methods, the control program causing the print setting apparatus to execute the procedures (A), (B) and (C). In the procedure (A), one color profile is selected as a color profile to be used for color conversion of the print data from a plurality of color profiles. In the procedure (B), it is determined whether a first calibration method executed at a time of creation of the one color profile selected in the procedure (A) agrees with a second calibration method currently registered in the image forming apparatus, with reference to the one color profile selected in the procedure (A) and a calibration table indicating a correspondence relation between output characteristic values of the image forming apparatus before and after correction by the second calibration method. In the procedure (C), a user is notified of a determination result in the procedure (B).
The objects, features, and characteristics of this invention other than those set forth above will become apparent from the description given herein below with reference to preferred embodiments illustrated in the accompanying drawings.
Hereinafter, an embodiment of the invention will be described in detail with reference to the drawings.
In
As shown in
As shown in
The print system S according to the embodiment has a function of executing calibration of the printer 3 according to a plurality of calibration methods. The “calibration” mentioned here refers to a procedure of correcting a change in output characteristics of the printer 3 to maintain color reproducibility of the printer 3 in a certain condition. More specifically, the print system S creates a correction table indicating a correspondence relation between output characteristic values (such as density values or brightness values) of the printer 3 before and after the calibration by means of a color measurement value of a color chart output by the printer 3 and a target table to be described below. Such a correction table is referred to as a “calibration table” below.
Software for performing detailed setting of the calibration of the printer 3 is installed in the controller 2 according to the present embodiment. Such software is generally referred to as a “calibration manager.”
On the calibration setting screen U1 in
Next, a detailed configuration of the PC 1 according to the present embodiment will be described. Since the controller 2 according to the present embodiment is an ordinary printer controller and the printer 3 according to the present embodiment is an ordinary printer, the detailed description thereof will be omitted. As shown in
The CPU 11 controls an operation of each unit according to a program stored in the storage unit 12 and executes various data processing. As shown in
Here, the print setting program P1 has a function of performing print setting of document files created by various applications. More specifically, the print setting program P1 has a function of generating print data of a document file and transmitting the print data to the printer controller 2. The print data according to the present embodiment is described in PDL (Page Description Language) such as Postscript (registered trademark).
Here, the printer profile is a conversion table (LUT: Look Up Table) indicating a correspondence relation between device values (CMYK values) and device-independent values (such as L*a*b* values, XYZ values, etc.) of an output apparatus (printer 3) in the color conversion process. The source profile is a conversion table (LUT) indicating a correspondence relation between a standard color space (such as JapanColor2011, GRACol, etc.) which is a target in the color conversion process, or device values (such as RGB values, CMYK values, etc.) of an input apparatus (such as a display, a scanner, etc.) and device-independent values (such as L*a*b* values, XYZ values, etc.). In the following description, L*a*b* values are used as the device-independent values.
Referring back to
The printer profile retrieval program P4 has a function of retrieving another color profile suitable for the calibration method registered in the current printer 3 when the determination result by the calibration method determination program P3 is “DISAGREEMENT.” The details of this function will also be described below with reference to
The storage unit 12 is a non-volatile storage area formed by a ROM (Read Only Memory), an HDD (Hard Disk Drive), or the like and has a function of storing various kinds of data including a control program of the PC 1. As shown in
Here, the “calibration target table” refers to a conversion table indicating a target value of the device-independent value corresponding to a device value after the execution of the calibration. The calibration target table is mainly used to create the calibration table (see
The “calibration table,” the “printer profile,” and the “source profile” have been described above. Also, the “rendering intent” refers to setting information regarding rendering intent selectable on the print setting screen illustrated in
The RAM 13 has a function of temporarily storing various kinds of data as a working area of the CPU 11. The operation unit 14 is a keyboard, a mouse, a touch panel, or the like and has a function of receiving various operation instructions from a user. The display unit 15 is a display device such as an LCD (Liquid Crystal Display) or an organic EL (electroluminescence) display and has a function of displaying various kinds of information to the user. In particular, setting screens exemplified in
Next, an overview of an operation of the print system S according to the present embodiment will be described.
First, the print system S executes calibration of the printer 3 by causing the respective apparatuses to cooperate with each other (step S101). More specifically, in step S101, a chart for calibration is printed by the printer 3 and a patch in the chart is measured by the color measuring apparatus 4. Then, the calibration table creation program P2 of the PC 1 is activated to create a calibration table. At this time, the calibration table creation program P2 creates the calibration table by means of the color measurement value acquired from the color measuring apparatus 4 and the calibration target table in the storage unit 12.
Subsequently, the print system S prints a color chart for profile creation without execution of the color conversion process by the controller 2 (step S102). In this example, a color chart conforming to the standard of ISO 12642 is adopted as the color chart for the profile creation. Then, the print system S measures the color patch in the color chart with the color measuring apparatus 4 (step S103).
Subsequently, the print system S creates a first LUT of the printer 3 by means of the color measurement value acquired in step S103 (step S104). More specifically, in step S104, an LUT (CMYK values=>L*a*b* values) in which color measurement values (L*a*b* values) respectively corresponding to 4-dimensional lattice points formed from C, M, Y, and K are described is created.
Subsequently, the print system S creates a second LUT of the printer 3 by means of the color measurement values acquired in step S103 (step S105). More specifically, in step S105, an LUT (L*a*b* values=>CMYK values) in which device values (CMYK values) respectively corresponding to 3-dimensional lattice points formed from L*, a*, and b* are described is created. The LUT created in this way is a printer profile of the printer 3. Thereafter, the print system S ends the profile creation process.
In step S105, various kinds of private information can be described in the printer profile. In particular, identification information of the calibration method executed in step S101 is preferably described as a part of the private information. The identification information described in the printer profile may be the calibration method itself or may be an attribute code corresponding to the calibration method. The step S104 and step S105 are executed by a profiler commercially available from each maker or a dedicated profiler designed to describe the above-mentioned identification information in the printer profile.
Consecutively, an overview of an operation of the print system S according to the present embodiment will be described.
Subsequently, the PC 1 receives selection of the source profile, the rendering intent, and the printer profile on the print setting screen U2 (step S203, step S204, and step S205). Thereafter, the PC 1 determines whether the calibration method currently registered in the printer 3 agrees with the calibration method executed at the time of the creation of the printer profile selected in step S205 (step S206). The process of step S206 is referred to as a “calibration method determination process” below.
The calibration method currently registered in the printer 3 refers to a calibration method executed at the time of the calibration executed finally at the present time. Also, the calibration method executed at the time of the creation of the printer profile refers to a calibration method registered in the printer 3 at the time of the printing of the color chart for the profile creation, i.e., the calibration method executed in step S101 of
The former calibration method is referred to as a “currently registered calibration method” below. The currently registered calibration method can be confirmed in a “set calibration method” field of the calibration setting screen in
Here, the printer profile selected in step S205 is created based on the color measurement values in a condition in which the latter calibration method has been executed. Therefore, when both of the calibration methods do not agree with each other, there is a probability that color reproducibility of the output image by the printer 3 deteriorates. For this reason, the PC 1 according to the present embodiment determines whether both of the calibration methods agree with each other and notifies the user of the determination result before the printing process of the printer 3. This point will be further described below.
However, when the identification information is not described in the printer profile, the calibration method at the time of the profile creation is identified in the following procedures of (1-1) and (1-2).
(1-1) The printer profile selected in step S205 is read out from the storage unit 12 and a combination of predetermined device values (CMYK values) and predetermined device-independent values (L*a*b* values) described in the printer profile is extracted.
(1-2) The calibration method determination criteria corresponding to the calibration methods are sequentially read out from the storage unit 12, and the combination extracted in the above procedure (1-1) and the determination criterion corresponding to each calibration method are collated. Then, the calibration method corresponding to the determination criterion with which the combination extracted in the above procedure (1-1) agrees is identified as the calibration method at the time of the profile creation.
Subsequently, the PC 1 identifies the currently registered calibration method based on the calibration table in the storage unit 12 (step S302). Then, the PC 1 determines whether the calibration methods identified in step S301 and step S302 agree with each other (step S303). Thereafter, the PC 1 returns the process to the flowchart of
Referring back to
Thereafter, the PC 1 receives an instruction of print execution from the user (step S217), and then ends the print setting process. This instruction can be received, for example, when an “OK” button b4 on the determination result notification screen in
Conversely, when the determination result of the calibration method determination process (step S206) is “DISAGREEMENT,” the PC 1 displays a determination result notification screen on the display unit 15 and notifies the user that the calibration method at the time of the profile creation disagrees with the currently registered calibration method on the same screen (step S208).
Subsequently, the PC 1 determines whether to receive an instruction to retrieve a suitable printer profile or an instruction to optimize the calibration table (step S209 and step S210) and branches the subsequent process according to the determination result. The former instruction is received, for example, when an “execution” button b3 of a “suitable printer profile retrieval” field on the determination result notification screen U3 in
Here, when the instruction to retrieve the suitable printer profile is received (YES in step S209), the PC 1 executes a process of retrieving another printer profile to be used instead of the printer profile selected in step S205 (step S211). The process of step S211 is referred to as a “printer profile retrieval process” below.
However, when the identification information is not described in the printer profile, the calibration method at the time of the profile creation is determined in the following procedures of (2-1), (2-2), and (2-3).
(2-1) The printer profiles are sequentially read out from the storage unit 12 and a combination of predetermined device values (CMYK values) and predetermined device-independent values (L*a*b* values) described in each printer profile is extracted.
(2-2) The calibration method determination criteria respectively corresponding to the calibration methods are sequentially read out from the storage unit 12, and the combination extracted in the above procedure (2-1) and the determination criterion corresponding to each calibration method are collated. Then, the calibration method corresponding to the determination criterion with which the combination extracted in the above procedure (2-1) agrees is identified as the calibration method at the time of the profile creation.
(2-3) The above procedures (2-1) and (2-2) are repeated for the remaining printer profiles in the storage unit 12.
Subsequently, the PC 1 identifies the currently registered calibration method based on the calibration table in the storage unit 12 (step S402). Then, the PC 1 extracts the printer profile which is other than the printer profile selected in step S205 and for which the currently registered calibration method is executed at the time of the creation by comparing the calibration methods identified in step S401 and step S402 (step S403).
Thereafter, the PC 1 displays a retrieval result display screen on the display unit 15, notifies the user of the retrieval result of the suitable printer profile on the same screen (step S404), and then returns the process to the flowchart of
Referring back to
Conversely, when no suitable printer profile is extracted in the printer profile retrieval process in step S211 (NO in step S212), the PC 1 creates a new calibration table optimized in accordance with the calibration method at the time of the profile creation (step S214). The process of step S214 is referred to as a “calibration table optimization process” below. Also, when the selection of the printer profile is received in step S213, the printer profile selected in step S213 is used in the color conversion process of the controller 2 instead of the printer profile selected in step S205.
When the instruction to optimize the calibration table is received in step S209 and step S210 (NO in step S209 and YES in step S210), the PC 1 creates a new calibration table optimized in accordance with the calibration method at the time of the profile creation (step S214). On the other hand, when neither of the instructions is received (NO in step S209 and NO in step S210), the PC 1 allows the process to proceed to step S217 without executing any process.
However, when the chart color measurement values at the time of the execution of the currently registered calibration method are not stored in the storage unit 12, the chart color measurement values are calculated in the following procedures of (3-1) and (3-2).
(3-1) The calibration table and the calibration target table corresponding to the currently registered calibration method are read out from the storage unit 12.
(3-2) The device-independent values (L*a*b* values) corresponding to the device values (CMYK values) before the correction by the currently registered calibration method is back-calculated with reference to a correspondence relation between target values (L*a*b* values) corresponding to the device values (CMYK values) after the correction shown in the target table read out in the above procedure (3-1) and output characteristic values (density values, brightness values, etc.) before and after the correction shown in the calibration table read out in the above procedure (3-1).
Subsequently, the PC 1 creates a new calibration table optimized in accordance with the calibration method at the time of the profile creation with reference to the target values (L*a*b* values) shown in the calibration target table read out in step S501 and the chart color measurement values (L*a*b* values) read out in step S502 (step S503). Thereafter, the PC 1 displays the optimization table display screen on the display unit 15 (step S504) and returns the process to the flowchart of
As in step S503, in the calibration table optimization process of
Referring back to
Thereafter, the PC 1 receives a print execution instruction (step S217) and terminates the print setting process (END). Also, when the new calibration table is registered in step S215, the newly created calibration table is used for the calibration of the printer 3.
As described above, the print setting apparatus (PC 1) according to the present embodiment can determine whether the calibration method executed at the time of the creation of the color profile for the color conversion agrees with the calibration method currently registered in the image forming apparatus (printer 3), with reference to the color profile for the color conversion and the correction table (calibration table) by the calibration method currently registered in the image forming apparatus (step S206) and notify the user of the determination result (step S208 and step S216). Accordingly, the print setting apparatus according to the present embodiment can effectively prevent color reproduction accuracy of an output image from deteriorating, when the calibration table by the calibration method executed at the time of the creation of the color profile for the color conversion is not registered in the image forming apparatus.
Further, even when the calibration method executed at the time of the creation of the color profile for the color conversion does not agree with the calibration method currently registered in the image forming apparatus (NO in step S207), the print setting apparatus according to the present embodiment can realize color reproduction expected by a user by optimizing the calibration table by the latter calibration method in accordance with the former calibration method (step S214) or by retrieving another color profile suitable for the latter calibration method (step S211).
The present invention is not limited to the above embodiment, but can be modified in various forms within the range of the claims. For example, in the above embodiment, the printer 3 has been adapted as the image forming apparatus that outputs print data. However, the image forming apparatus according to the present invention may be an MFP (Multi-Function Peripheral) that further has a scan function, a copy function, etc. Also, the device-independent values used for the color conversion process of the print data may not be the L*a*b* values, but may be other device-independent values such as XYZ values.
The means and methods of executing the various processes in the print setting apparatus (PC 1) according to the present embodiment may also be realized by one of a dedicated hardware circuit and a program executed on a computer. The program may be provided by a computer-readable recording medium such as a flexible disk or a CD-ROM (Compact Disc Read Only Memory) or may be provided online via a network such as the Internet. In the former case, the program stored in the computer-readable recording medium is generally transmitted to a non-volatile memory such as a ROM or an HDD. Also, the above program may be provided as single application software or may be embedded as one function of the print setting apparatus.
Number | Date | Country | Kind |
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2013-087762 | Apr 2013 | JP | national |