Printing specification method and printing specification device

A printing specification method and printing specification device for specifying a spot color, which differs from process colors, as a substitution color, when setting the substitution color for a color plate of one of the process colors and performing printing processing. The printing specification method includes extracting spot colors from a spot color database, displaying a list of names of the extracted spot colors, and specifying a spot color corresponding to a name that has been selected from the list as the substitution color. The spot color database is based on color information which includes characteristic values, which specify the spot colors, and spot color names. The extraction is performed on the basis of a characteristic value which sets a reference point and of a tolerance range of this characteristic value.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 USC 119 from Japanese Patent Application No. 2004-074727, the disclosure of which is incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a printing specification device which is capable of printing simulations which employ spot colors, which are colors that differ from process colors, and more particularly relates to a printing specification method and printing specification device for times of performing printing simulations that employ spot colors.

2. Description of the Related Art

Desktop publishing (DTP) creates a page layout by implementation of image creation, processing, editing, etc. on a processing device such as a personal computer, a workstation or the like. On the basis of this page layout, a film for exposure of a printing plate is created (CEPS), the printing plate is directly written therefrom, and a plate for production printing is created (CTP: Computer-To-Plate).

When proofreading or the like is to be carried out before actual production printing with a printing plate, WYSIWYG functions or the like may be utilized to print out a page layout that is displayed on a monitor from a printout device, such as a page printer or the like (comprehensive layout output).

In usual color printing, the four colors cyan, magenta, yellow and black are employed (i.e., process colors). However, printing is sometimes, depending on requirements, implemented using ink of a color which differs from the process colors (below referred to as a spot color). In recent years, in order to reduce printing costs, two-color printing or the like is sometimes implemented. At such times, particular effects may be obtained by using one of the process colors and a spot color, or two spot colors.

When a two-color printing simulation is performed in order to obtain a color comparison printout with a spot color, if it is only possible to obtain a printout with process colors, it will be difficult to ascertain how the actual printed matter will appear.

Accordingly, a process has been proposed which implements a spot color printing simulation by: actually using printing plates to perform printing of a color chart with spot color inks that are expected to be used in two-color printing; creating a spot color profile (a CMYK-L*a*b* lookup table) by measurements of this color chart; and utilizing this spot color profile with a printer profile (an L*a*b*-C′M′Y′K′ lookup table) to implement CMYK-C′M′Y′K′ conversions with color management functions.

Further, a color comprehensive layout output method has been proposed which replaces each color of a document created using, for example, any two colors of C, M, Y and K with the color of a desired ink (a spot color).

However, there are numerous ink makers, each of whom produces hundreds or thousands of spot colors. Thus, when a spot color is being assigned for performing a printing simulation, it is necessary to input text of a maker name, a spot color name and so forth.

Consequently, if there is an input error such as a spelling mistake or the like, it will not be possible to execute the printing simulation with the desired color. Moreover, there is a problem in that, in order to input text of a spot color name, it is necessary to know the hue and name of a spot color beforehand.

Furthermore, if expected results are not obtained when a previously known spot color is used, it is necessary to search for a similar spot color, which is not a simple task in practice.

There is also a method in which a spot color name is selected from a list of spot colors which have been specified beforehand. However, because such lists are displayed in a different name order for each maker, it is not possible to distinctly judge between the hues. Furthermore, because there are separate lists for each ink maker, selection of a desired spot color from among the different makers is a difficult task.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above circumstances and provides a printing specification method and a printing specification device.

A first aspect of the present invention is a printing specification method for specifying a spot color, which differs from process colors, as a substitution color when setting the substitution color for a color plate of one of the process colors and performing printing processing, the method including the steps of: on the basis of a characteristic value which sets a reference point and of a tolerance range of this characteristic value, extracting corresponding spot colors from a database of spot colors, the database being based on color information including characteristic values, which specify the spot colors, and spot color names; displaying a list of names of the extracted spot colors; and specifying a spot color corresponding to a name selected from the list as the substitution color.

A second aspect of the present invention is a printing specification device that specifies a spot color, which differs from process colors, as a substitution color when setting the substitution color for a color plate of at least one of the process colors and performing printing processing. The device includes an spot color extraction component which, on the basis of a characteristic value which sets a reference point and of a tolerance range of this characteristic value, extracts corresponding spot colors from a database of spot colors, the database being based on color information including characteristic values, which specify the spot colors, and spot color names; a display which displays a list of names of the extracted spot colors; and a spot color specification component which specifies a spot color corresponding to a name selected from the list as the substitution color.

DETAILED DESCRIPTION OF THE INVENTION

Herebelow, an embodiment of the present invention will be described with reference to the drawings.FIG. 1shows general structure of a network10at which the present embodiment is applied. In this network10, a print server12and a plurality of client terminals14are network-connected by a communications circuit16. The print server12is provided to serve as an image processing device, and the client terminals14are provided to serve as image processing terminals.

A printer18, serving as a printing output device, is also connected to the print server12. When the print server12receives a print job outputted from the client terminals14, the print server12uses the printer18to perform a printout in accordance with the print job.

An image processing device which is employed as the print server will be described herebelow. However, the image processing device of the present invention is not limited thus, and could be a device which is provided to perform image processing at any of various intermediate servers, such as a file server or the like which is network-connected with the client terminals14. Further, not necessarily the printer18, but a plate-setter, which directly exposes photosensitive planographic printing plates in accordance with image data in order to prepare the printing plates for printing, an exposure device which exposes original films, which are utilized for burning (exposing) images onto photosensitive planographic printing plates, or the like may be connected.

Network interfaces (network I/F)20and22are provided at the print server12and the client terminals14. The print server12and the client terminals14are connected to the communications circuit16through these network interfaces20and22. The print server12is further provided with a bidirectional interface (bidirectional I/F)24. The print server12is connected to the printer18through this bidirectional I/F24.

Herein, a plurality of the printer18may be connected to the print server12, and a plurality, or even a plurality of types, of the bidirectional I/F24may be employed. Furthermore, a freely selected network protocol may be employed for network connections of the plurality of client terminals14and the print server12.

The print server12described above may be structured by adding a PCI board equipped with predetermined functions to a personal computer (PC) or suchlike. Further, the print server12may be an apparatus which is provided with an input device such as a keyboard, a mouse or the like and a display device such as a CRT display, an LCD display or the like, and which is provided with WYSIWYG functions for processing images displayed at the display device and printing out the displayed images.

A print controller26, an image processing section28and an HDD30are provided at the print server12. The print controller26controls the printer18and the print server12itself, and the HDD30serves as a storage component which stores various kinds of data. The image processing section28carries out RIP processing to create raster data on the basis of job data, such as image data, drawing instructions and the like which are inputted in the form of print jobs from the client terminals14.

The print server12stores the inputted print jobs in a processing queue. The print jobs stored in the processing queue are read out sequentially and image processing (RIP processing) is executed. The image-processed data which is to be outputted to the printer18(i.e., raster data) is stored in a printing queue, and is sequentially outputted from the printing queue to the printer18. Further, the print server12has an ordinary structure in which jobs for which printing processing is not instructed or for which printing processing cannot be executed are stored and retained in a holding queue. The print server12as described hereabove can employ various conventionally known structures, and is not described in detail for the present embodiment.

The client terminal14is provided with a DTP application (below referred to as the “application32”). The client terminal14uses this application32to perform image processing and the like, including creation, processing, editing and so forth of images, texts, etc. The application32enables the client terminal14to create image data and/or drawing commands (below referred to as image data) for printing of page layouts and the like with printing plates.

A printer driver (driver software)34is also provided at the client terminal14. Through this printer driver34, the client terminal14can send jobs (print jobs) including image data, such as page layouts and the like prepared by the application32or the like, and various processing instructions to the print server12. At this time, it is possible to specify various printing functions with the printer driver34.

Further, because this printer driver34is employed at the client terminal14, it is possible to apply various settings and the like to the print server12.

A print function setting section36is provided at the print server12. When the print server12receives a job, such as a print job or the like, settings of various printing functions which are designated by the print job are implemented. Herein, setting of conventionally known printing functions at the print server12is possible. The print function setting section36assesses the printing functions designated by the print job, and sets execution of each printing function at the print controller26and the image processing section28. However, this is not described in detail for the present embodiment.

A color substitution processing section38is also provided at the print server12. When substitution of a designated color is specified for a drawing object with a color assigned, such as an image, a text or the like, this color substitution processing section38implements a color substitution in accordance with the specification.

L*a*b* values which are specified beforehand for each of spot colors, separately from the process colors cyan (C), magenta (M), yellow (Y) and black (K), and a table for converting the L*a*b* values to CMYK values (a profile) are stored in the HDD30which is provided at the print server12to serve as the storage component.

When a color substitution of a spot color for the color plate of any of the process colors is instructed, the color substitution processing section38refers to the L*a*b* values of the corresponding spot color and the look-up table (LUT) for converting these L*a*b* values to CMYK values, which are stored in the HDD30, implements an update (a substitution) of color information, and generates new color information. That is, the new color information (CMYK values) is generated by combining the CMYK values of the spot color designated by the color substitution with the CMYK values of the color plates other than the color plate designated by the color substitution.

Accordingly, it is possible when, for example, creating image data and/or text data for two-color printing using two arbitrary colors selected from the process colors, to print out with a spot color(s) differing from the process colors as one or both of those two colors.

That is, simulations of cases in which printing processing will be performed using inks which differ from the process colors at the time of printing out with printing plates are possible.

For this color substitution processing, a CMYK printout region and a CMYK color correction region are constituted in, for example, a memory provided at the image processing section28. When image processing is to be carried out on an image in a print job (an image object), CMYK values of the spot color (the CMYK values that have been converted from the L*a*b* values) are stored in the CMYK printout region.

Further, CMYK values of the process colors that are to be used for this image object are stored in the CMYK color correction region. After color correction has been performed on the CMYK values stored in the CMYK color correction region, new color information for this drawing object is generated by combining the corrected CMYK values with the CMYK values stored in the CMYK printout region, and this new color information is outputted.

The provision of the color substitution processing section38as described above enables N-color printing simulations that utilize spot colors at the print server12. Herein, arbitrary structures can be employed for the color substitution processing, and are not described in detail for the present embodiment.

Settings of N-color printing simulations, which are provided as a function of the print server12, can be made from the printer driver34provided at the client terminal14. A user interface (UI) is specified for making these settings.

Consequently, settings of N-color printing simulations, such as two-color printing simulations and the like, can be made from the client terminal14with ease by using the user interface.

A spot color management section40is constituted at the print server12, and a spot color database42is stored at the HDD30. The database42is administered by the spot color management section40. Numerous spot color names are registered in the database42, and a manufacturing maker (i.e., the maker's name) and L*a*b* values are stored with each spot color name in the database42.

Hence, when a two-color printing simulation in which a spot color is assigned is specified at the print server12, the L*a*b* values of the assigned spot color name are read out, and it is possible to perform color substitution processing therewith.

Meanwhile, at the client terminal14, when the printer driver34is used to perform a color substitution with a spot color, it is possible to display a color palette.FIG. 2shows an example of a color palette46. This color palette46contains information corresponding to L*a*b* values, which information corresponds to L*a*b* values at each position of the color palette46that can be designated. Note that the color palette46illustrates an example, and structures of color palettes of the present invention are not limited thus. A color palette of the present invention can employ an arbitrary structure as long as the color palette includes display colors and color information corresponding to the display colors.

Thus, given L*a*b* values of a color, the client terminal14can find information corresponding to L*a*b* values of a color of the color palette46that is closest to that color, and display the color found on the color palette46.

At the printer driver34provided at the client terminal14, L*a*b* values of a color designated by, for example, a pointer48on the color palette46, tolerance ranges of the L* value, the a* value and the b* value, and manufacturing makers are assigned, and the printer driver34requests a list of spot colors with L*a*b* values within these tolerance ranges.

When the list of spot colors is requested by the client terminal14, the spot color management section40of the print server12extracts corresponding spot colors from the database42and sends the spot colors to the client terminal14.

Thus, when a color assigned in the color palette46is changed, the client terminal14can display the relevant color and a list of spot colors that are similar to that color.

Further, by selection of a spot color name from the displayed list of spot colors, the client terminal14can specify a printing simulation which employs the spot color with the selected spot color name.

At the print server12described above, image data and/or drawing instructions, for which processes such as creation, processing, editing, etc. have been carried out with the application32, are received from the client terminal14in the form of a print job. When this print job is received, the print server12executes image processing and printing processing in accordance with the received print job.

When a print job is received by the print server12, reading and setting of printing functions is performed by the print function setting section36. At the image processing section28, image processing is carried out on the image data of the print job in accordance with the specified printing functions and RIP processing is performed to generate raster data.

The raster data created by the image processing section28is outputted to the printer18with a predetermined timing, and printing output based on the print job is implemented by the printer18.

Here, it is possible to set N-color printing simulation as a printing function at the print server12. Further, when an N-color printing simulation is to be performed, assignment of a spot color is possible. Thus, N-color printing simulations employing spot colors are enabled.

Now, a color substitution with a spot color and an N-color printing simulation will be described with reference toFIGS. 3A to 6B.

When an N-color printing simulation is to be performed at the print server12, a user interface (UI) is used at the client terminal14for specifying the color plates to be employed. For example, when there is an image with a C plate, an M plate, a Y plate and a K plate, it is possible to specify the use of those color plates and, as necessary, to assign process colors and/or spot colors as colors for when these color plates are printed.

FIG. 3Ashows an outline of printing specification at the client terminal14when an N-color printing simulation is to be performed. This flowchart is executed when the N-color printing simulation is being specified. In step100, a printing settings dialog employed in setting the N-color printing simulation is displayed.

FIGS. 4A and 4Bshow the main elements of a settings dialog50, which serves as an example of the user interface at the client terminal14at the time of specifying an N-color printing simulation. As shown inFIG. 4A, it is possible, at a check box52in the settings dialog50, to specify whether or not an N-color printing simulation is to be performed. Further, when the check box52has been checked to specify that the N-color printing simulation should be performed, checking of check boxes54C,54M,54Y and54K (which are referred to collectively as check boxes54), which are provided for the C plate, the M plate, the Y plate and the K plate, respectively, is enabled.

Here, as an example, the check boxes54C and54M for the C plate and the M plate are checked in the settings dialog50, thus specifying a two-color printing simulation using the C plate and the M plate.

Input boxes56C,56M,56Y and56K (which are referred to collectively as input boxes56) and color selection buttons58C,58M,58Y and58K (which are referred to collectively as color selection buttons58) are also provided in the settings dialog50for the C plate, the M plate, the Y plate and the K plate, respectively. When a check is put in one of the check boxes54, entry of text (text input) into the input box56for the corresponding color plate and operation of the corresponding color selection button58are enabled.

When a spot color name is entered into any of the input boxes56of the settings dialog50, specification of an N-color printing simulation employing the spot color with the entered color name (spot color name) is enabled.

Further, when any of the color selection buttons58in the settings dialog50is operated, a list of spot colors stored in the database42of the print server12is displayed, and it is possible to input the color name of a spot color selected from the displayed list into the input box56.

Selected colors are shown at the color selection buttons58as default values. Specifically, in a state in which no substitution colors are assigned, the color selection button58C for the C plate, the color selection button58M for the M plate, the color selection button58Y for the Y plate and the color selection button58K for the K plate show a color C, a color M, a color Y and a color K, respectively.

Thus, the client terminal14enables selection of a substitution color for a color plate by operation of the corresponding color selection button58in the settings dialog50.

Step102inFIG. 3Aascertains whether or not an N-color printing simulation is to be specified, and step104ascertains whether spot color selection is to be performed.

Accordingly, if the check box52in the settings dialog50is checked and one or more of the check boxes54is checked, the determination of step102is positive and an N-color printing simulation is to be specified. Then, when any of the color selection buttons58is operated, the determination of step104is positive and a spot color selection is implemented.

The spot color selection is carried out using a user interface at the client terminal14.FIGS. 5A,5B,6A and6B show a spot color selection dialog60, which serves as an example of a user interface employed for the selection of a substitution color. As shown inFIG. 5A, the color palette46is displayed in this spot color selection dialog60and the default color is indicated by the pointer48.

A list display area62, an input box64and slide bars66are provided in the spot color selection dialog60. A designation of makers of the spot colors is entered at the input box64. The slide bars66are for input of tolerance ranges of L* values, a* values and b* values.

Default values of maker names and the tolerance ranges are set in the spot color selection dialog60. When the spot color selection dialog60is opened, a list of spot colors based on the default values of the assigned color and the tolerance ranges is displayed in the list display area62.

When the spot color selection dialog60is displayed, the printer driver34of the client terminal14sends a request for the list of spot colors based on the default values of the assigned color and the tolerance ranges.

That is, as shown inFIG. 3A, when the determination of step104is positive and the process advances to step106, first, the spot color selection dialog60is displayed. Then, in step108, the request for a list of spot colors is sent to the print server12. When the list of spot colors is acquired, the process advances to step110, and the acquired list of spot colors is displayed in the list display area of the spot color selection dialog60.

FIG. 3Bshows an outline of processing at the print server12corresponding to the spot color selection at the client terminal14. In a first step130of this flowchart, it is ascertained whether or not output of a list of spot colors has been requested. When a list of spot colors is requested, the determination of step130is positive and the process advances to step132.

In step132, the spot color management section40extracts spot color names that meet the conditions assigned by the client terminal14from the database. In a subsequent step134, the spot color management section40outputs a list of the extracted spot color names to the client terminal14.

In other words, at the print server12, the spot color management section40performs an extraction of spot colors on the basis of the assigned color and the specified tolerance ranges (which are all initially at the default values), and the results of extraction are outputted to the client terminal14to serve as the list of spot colors.

Thus, when the spot color selection dialog60at the client terminal14has been opened (step106inFIG. 3A), a predetermined list of spot colors is displayed in the list display area62of the spot color selection dialog60.

FIG. 5Ashows a display when the color selection button58C, which corresponds to the C plate, is operated in the settings dialog50ofFIG. 4A. Accordingly, in the spot color selection dialog60inFIG. 5A, “CYAN” (the C process color) and a list of names of spot colors which are close to C is shown in the list display area62. At this time, the list entry for C, which is the assigned color, is shown highlighted.

In the flowchart ofFIG. 3A, when the list of spot colors has been displayed at the list display area62of the spot color selection dialog60, step112ascertains whether the assigned color has been changed, and step114ascertains whether or not a restriction has been applied, such as a change in a tolerance range or the like.

In the spot color selection dialog60shown inFIG. 5A, the pointer48is pointed to a desired color on the color palette46. As a result, a list of spot colors for which offset amounts of L*a*b* values relative to that color (which may be a process color or a spot color) are within the tolerance ranges designated by the slide bars66is displayed at the list display area62.

Thereafter, when the assigned color is changed at the client terminal14, a list corresponding to the new assigned color is requested. That is, the determination of step112inFIG. 3Ais positive and the process returns to step108.

At the print server12, spot colors are extracted on the basis of the designated color (the assigned color) and are outputted to the client terminal14. Hence, at the client terminal14, this list of extracted spot colors is displayed at the list display area62of the spot color selection dialog60; i.e., the display is updated (step110ofFIG. 3A).

FIG. 5Bshows a display example of the spot color selection dialog60when the assigned color has been changed at the color palette46. A color designated by the pointer48or a spot color corresponding to a color which is closest thereto is shown highlighted, and similar colors within the tolerance ranges of that spot color are shown as a list.

Further, in the spot color selection dialog60it is possible to apply a restriction to the list displayed in the list display area62. Such restrictions can utilize maker designations and the tolerance ranges. Herein, the default value of the maker name is “All” (all makers).

When a restriction with a manufacturing maker is to be applied, the maker name to be designated is entered at the input box64of the spot color selection dialog60. An arbitrary method can be used for this maker input, such as displaying a list of maker names that are registered in the database42with a pull-down menu or the like and selecting from this displayed list, or the like.

When a maker name is designated in the spot color selection dialog60, the determination of step114of the flowchart shown inFIG. 3Ais positive. The process returns to step108, and a list of spot colors based on the altered conditions is requested.

When a maker name is designated, the spot color management section40provided at the print server12extracts, from the spot colors that were previously extracted, spot colors from the corresponding maker(s) and outputs these spot colors to the client terminal14.

When the client terminal14receives the new list of spot colors, in step110, the spot color selection dialog60is displayed in accordance with the received list.

Accordingly, the list of spot colors of the designated maker(s) is displayed at the list display area62of the spot color selection dialog60, as shown inFIG. 6A. Here, it is possible that requests will be sent from the client terminal14only at times of broadening of the tolerance ranges of the assigned color and that, at times of narrowing of the tolerance ranges, restrictions will be applied within the client terminal14to the most recently acquired list.

Further, it is possible to change the tolerance ranges of the L* value, the a* value and the b* value, which serve as restriction conditions of the spot colors, from the spot color selection dialog60. When the tolerance ranges of the L* value, a* value and b* value are to be changed, it is possible to set respective tolerance ranges for each of the L* value, the a* value and the b* value by using the slide bars66. Herein, the tolerance ranges at such times utilize offset values (percentages or the like) of the L* value, the a* value and the b* value with respect to the assigned color.

Here, when the slide bars66are operated so as to narrow the tolerance ranges of any of the L* value, the a* value and the b* value, the determination of step114in the flowchart ofFIG. 3Ais positive, the process returns to step108, and a list of spot colors that satisfy the altered tolerance conditions is requested.

When a list is provided from the print server12on this basis, the process advances to step110, and the spot color selection dialog60is displayed in accordance with the new list.

FIG. 6Bshows the spot color selection dialog60when a restriction narrowing the tolerance ranges of the L*a*b* values has been applied. It is also possible to broaden the tolerance ranges with the slide bars66, and it is accordingly possible to increase the number of spot colors displayed in the list display area62and to broaden a selection range of the spot colors.

It is possible to restrict and display candidates for the desired color by applying restrictions in the spot color selection dialog60in this manner. Hence, when a spot color is to be set, the spot color is selected from the spot color names displayed in the list display area62and switched to highlighted display, after which a setting button (an OK button68) is operated.

Thus, it is possible to set the spot color to be a substitution color when the N-color printing simulation is implemented.

In the flowchart shown inFIG. 3A, step116ascertains whether or not a spot color has been set. When a spot color has been set, the determination of step116is positive and the process advances to step118. The spot color selection dialog60is closed and the spot color selection is finished. Accordingly, the client terminal14returns to the state in which the settings dialog50is displayed.

FIG. 4Bshows an example of display at such a time. Specifically, inFIG. 6B, “D149” has been selected as a spot color to substitute for the C plate. When the spot color is set in accordance with this selection result, this spot color name is entered at the input box56C inFIG. 4Band the display color of the color selection button58C is changed to the selected spot color.

In the flowchart ofFIG. 3A, when the printing settings dialog50has been displayed with the spot color name of the specified spot color entered therein (step118), the process advances to step120and it is ascertained whether or not the printing specification has been completed. Here, if one of the color selection buttons58is operated to set another substitution color for a color plate, the determination of step120is negative, the process returns to step102, and the processing is carried out for the next substitution color.

On the other hand, when a set button or OK button of the printing settings dialog50is operated, the determination of step120is positive and the printing specification finishes.

Thus, it is possible, at the client terminal14, to simply and accurately input spot color names when color substitutions with spot colors and N-color printing simulations are to be implemented.

Furthermore, at the client terminal14, it is possible to check assigned colors on the color palette46while selecting spot colors. At such times, because similar colors are displayed together, it is possible to select spot colors for desired colors accurately.

The present invention is not limited to the present embodiment as described above. For example, although an example has been described for the present embodiment in which the spot color selection dialog60serves as the user interface when a spot color is being selected, user interfaces with arbitrary structures may be employed.

For example, the user interface may have a form such that selection of spot colors for each of a plurality of color plates is possible. As an example thereof,FIG. 7shows a spot color selection dialog70, which is an example of a user interface which enables selection of spot colors for two of the color plates.

For example, if a two-color printing simulation using the C plate and the M plate or the like is to be specified, the spot color selection dialog70can be employed when carrying out a selection of spot colors as substitution colors. A spot color selection section72for the C plate and a spot color selection section74for the M plate are displayed in the spot color selection dialog70at the same time.

A preview display section76is also provided in the spot color selection dialog70. This preview display section76displays color patches of cases in which densities of a spot color for the C plate and a spot color for the M plate are respectively varied and mixed.

When the spot color selection dialog70with this form is employed, it is possible to verify hues of the finished article if the two-color printing simulation is to be implemented with the spot colors. Thus, more accurate selection of a combination of a spot color with a spot color is enabled.

In the spot color selection dialog70with this form, the color patches of the preview display section76may be shown using an image selected by the user beforehand. Alternatively, a preview image of the image for which printing processing is to be executed may be displayed instead of the color patches.

In the present embodiment as described above, the tolerance ranges are used as restriction conditions for the list of spot colors. However, ranges of ratios of offsets of the L*a*b* values, ranges of offset amounts or ratios of other characteristic values of color, such as RGB or CMYK values or the like, or the like may be used.

It is also possible to include ink prices, delivery times, availability of stock and so forth in the database42for each spot color, and hence to use these kinds of information as restriction conditions. Furthermore, it is possible to prepare a database in which each spot color is categorized in accordance with an impression of the color, with natural language such as “relaxing”, “summery” and suchlike, or the like, and accordingly to display lists using these categories as keywords.

In the present embodiment, the color palette46is used to assign a color as a reference point. However, the present invention is not limited thus and arbitrary structures may be employed: a reference point color may be assigned using a list of typical colors which has been prepared in advance; colors may be inputted using a scanner, a color measurement instrument or the like; characteristic values of colors, such as L*a*b* values and the like, may be inputted as numerical values; and so forth.

In the present embodiment, use of the color palette46, whose horizontal axis represents brightness (the L* value) and whose vertical axis represents color (meaning hue and chroma), has been described. However, if L*a*b* values are to be used as the characteristic values, a color palette with an arbitrary structure may be employed as long as it features display colors and information corresponding to L*a*b* values.

It is further possible to employ, as the color palette, an arbitrary structure in which typical colors are displayed, a selection is made from the displayed typical colors, and hence the selected color and colors similar to the selected color are displayed, or suchlike.

For the present embodiment, the spot color list displayed at the list display area62is changed automatically when the color palette46of the spot color selection dialog60is clicked on. However, instead of this, it could be that when some spot color displayed in the list display area62is assigned (clicked on), that color's name is shown highlighted, automatic movement of the pointer48on the color palette46in accordance with the L*a*b* values of that spot color is implemented, the selected spot color is displayed on the color palette46, and an update of the spot color list displayed at the list display area62is performed with that color as the assigned color.

For the present embodiment, L*a*b* values have been used as the characteristic values. However, the present invention is not limited thus. As long as the values represent characteristics of the colors, it is possible to employ CMYK values, XYZ values, RGB values or the like. In such cases, as well as a density value of 100%, pluralities of values in which density is varied in steps of 5%, 25% or the like may be included.

In the present embodiment, the database of spot colors is kept at the print server12. However, the database may be kept at any of the client terminals14, or may be kept at a Web server to which connection over the Internet or the like is possible, at a maker of the print server12, a manufacturing maker of the spot colors or the like. If there is a plurality of print servers in the network, the database may be kept at a dedicated print server, and it may be possible to perform spot color printing using an arbitrary print server.

Note that the present embodiment as described above illustrates an example of the present invention, and does not limit structures of the present invention. For example, in the present embodiment, the print server12has been described as an example. However, the present invention is not limited by the print server12. An image processing device with an arbitrary structure which is capable of image processing in accordance with image data and drawing commands prepared at the client terminals14may be employed.

Furthermore, an example of selection of spot colors for when carrying out printing processing has been described for the present embodiment. However, the present invention is not limited thus, and can be utilized for selection of various colored materials and the like, such as: coating materials such as paint, art paints and the like; color pens; color pencils; fibers; paper (origami paper, colored paper, etc.); fabrics; films; and so forth.

As has been described above, the present invention is a printing specification method for specifying a spot color, which differs from process colors, as a substitution color when setting the substitution color for a color plate of one of the process colors and performing printing processing, which method includes: on the basis of characteristic values which set a reference point and of tolerance ranges of these characteristic values, extracting corresponding spot colors from a database of spot colors, the database being based on color information including characteristic values, which specify the spot colors, and spot color names; displaying a list of names of the extracted spot colors; and specifying a spot color corresponding to a name selected from the list as the substitution color.

In the present invention, it is possible to select the characteristic values to set the reference point by selecting the position of a color in a color palette as the reference point.

According to this invention, when a color palette is employed, visual selection of spot colors is enabled. When, for example, L*a*b* values are used as the characteristic values, a palette that features information corresponding to selection positions and L*a*b* values can be employed as this color palette.

When a color palette is being used, it is possible to set a position of assignment on the color palette to a position based on the characteristic values of a selected spot color by selecting that spot color from the list.

If the characteristic values are displayed as numerical values such as L*a*b* values or the like, setting of the characteristic values for the reference point may be done by entering numerical values. Further, characteristic values which have been detected or measured with a scanner, a color measurement instrument or the like may be utilized. In such a case, this is made possible by setting an input component for inputting the characteristic values beforehand. Further again, the characteristic values are not limited to L*a*b* values: CMYK values, XYZ values, RGB values and the like may be employed. In such a case, rather than only a density value of 100%, values in which density is varied in steps of 5%, 25% or the like may be included.

Accordingly, it is possible to re-set the characteristic values for the reference point simply and accurately from the displayed list of spot colors. Here, when the reference point values have been re-set, the spot colors may be extracted from the database again, on the basis of these reference point values, and displayed in the list.

In the present invention as described above, it is preferable if the tolerance ranges relative to the characteristic values that set the reference point can be altered. Hence, broadening of the tolerance ranges is simple, and it is possible to simply and accurately reduce and increase the number of spot color names displayed in the list.

Furthermore, in the present invention, it is preferable to assign color information and perform the extraction of spot colors on the basis of the tolerance ranges and the assigned color information.

Hence, if, for example, the names and suchlike of the makers who manufacture the spot color inks are included in the color information, it is possible to display spot colors in lists separated by maker.