Image forming apparatus and method of controlling image forming apparatus

An image forming apparatus not having a spot color printing function and connected a network cannot print out a proper image from image data which is already processed for spot color and stored in an image forming apparatus having a spot color printing function. When the image data subjected to the spot color process is stored in the image forming apparatus having the spot color printing function, difference information is stored together with the image data subjected to the spot color process. In order to print the data by a four-color output type of image forming apparatus not having the spot color printing function, the data is restored into four-color image data on the basis of the difference information, and the four-color image data is transmitted to the image forming apparatus not having the spot color printing function.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image processing method for efficiently printing out image data for spot color printing by use of an image forming apparatus which is not compatible with the spot color printing.

2. Description of the Related Art

In recent years, digital printing techniques have steadily been increasing their utility values in markets, such as an on-demand printing market and a small-lot document printing market. Particularly, full-color printing using an electrophotographic technique is in a superior position to other printing techniques in light of productivity, printing costs, easy maintenance, and so forth and is therefore rapidly expanding the market. In terms of such color printing, attention is drawn to not only conventional full-color printing according to electrophotographic printing that uses four color toners of C (cyan), M (magenta), Y (yellow), and K (black) but also multiple-color printing methods using an additional special toner. Accordingly, these multiple-color printing techniques are now with an eye toward a market of special printing that highly requires on-demand and immediate printing performance. Such special toners include, for example, a transparent toner which is capable of absorbing irregularities on a surface of a printed sheet and achieving high glossiness, and a light toner which is capable of reducing roughness of a highlighted part. By using the special toners, it is possible to gain new added-values that are different from what is obtainable by normal digital printing, and hence to further expand the world of digital printing. From the above-described background, image forming apparatuses which are generally called multifunction printers (hereinafter referred to as “MFPs”) and equipped with special toners are now being brought to the market in addition to conventional color MFPs configured to perform conventional four-color printing.

Moreover, for effectively using special toners, a large number of application software products capable of handling a spot color other than C, M, Y, and K are being brought to the market. It is possible to generate image data containing the spot color by using such application products.

Although image data containing a spot color has started to be used as described above, it is not always true that every MFP used today is compatible with the spot color. Specifically, it is highly likely that a print job is sent to a network which includes both of an MFP compatible with a spot color toner and an incompatible MFP using the conventional four colors of C, M, Y, and K. This situation causes a problem of inefficiency in which an unnecessary rendering operation for a spot color is performed even when image data containing the spot color is to be printed out by an MFP which is not compatible with the spot color. To solve this problem, Japanese Patent Laid-Open No. 2008-028917 discloses a method of determining prior to printing whether or not to use a spot color, and then determining whether to perform rendering for the spot color or rendering for the conventional four colors according to the determination result.

In recent years, environments have been created in which image data stored in a storage component of a certain MFP can be printed out by using another MFP connected to the same network. Under such an environment, the technique described in Japanese Patent Laid-Open No. 2008-028917 cannot deal with a case where image data stored in a spot color compatible MFP that has performed spot color printing of the image data is to be printed by another MFP not compatible with spot color printing. This is because the image data stored in the storage component of the spot color compatible MFP has already been rendered for the spot color. Therefore, when a conventional four color MFP is designated as a printer for printing the image data already rendered for the spot color, a problem arises that the MFP is incapable of printing the image data properly. To be more precise, the MFP is incapable of printing the image data from the beginning, or incapable of reproducing proper colors in a part of the image data rendered for spot color even when the MFP prints out the image data by using the four colors only.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a technique for a technique for allowing even an MFP incompatible with spot color printing to print out an image with satisfactory quality from image data already rendered for spot color, when the MFP is designated as a printer for printing.

An image forming apparatus of the present invention which is connected to a network and provided with a spot color printing function, comprises: a generating component configured to generate spot color image data and four-color image data; a difference extracting component configured to extract difference information indicating a difference between each pixel value of a CMYK version of the spot color image data and a corresponding pixel value of the four-color image data, by using the spot color image data and the four-color image data, a storing component configured to store the spot color image data and the difference information; a determining component configured to determine, at a time of performing printing by a different image forming apparatus through the network, whether or not the different image forming apparatus has the spot color printing function; an image data restoring component configured to restore four-color image data by using the spot color image data and the difference information, which are stored in the storing component, when the determining component determines that the different image forming apparatus does not have the spot color printing function; and an image data transmitting component configured to transmit the restored four-color image data to the different image forming apparatus.

Alternatively, an image forming apparatus of the present invention which is connected to a network and provided with a spot color printing function, comprises: a user interface configured to receive an instruction from a user; a generating component configured to generate spot color toner print position information and four-color image data on the basis of an image design designated through the user interface; a component configured to store the four-color image data and the spot color toner print position information; a determining component configured to determine, at a time of performing printing by a different image forming apparatus through the network, whether or not the different image forming apparatus has the spot color printing function; and an image data transmitting component configured to transmit, not the spot color toner print position information, but the four-color image data to the different image forming apparatus, when the determining component determines that the different image forming apparatus does not have the spot color printing function.

According to the present invention, it is possible to store image data automatically in such a way as to obtain optimum image quality according to the type of an image forming apparatus in consideration of a possibility that the image forming apparatus at an output destination does not have a spot color printing function. Therefore, a user does not have to consider the types of image forming apparatuses in a network printing environment that includes both an image forming apparatus compatible with spot color printing and an image forming apparatus not compatible with spot color printing.

DESCRIPTION OF THE EMBODIMENTS

Embodiment 1 of the present invention will be described below with reference to the accompanying drawings.

Embodiment 1 will be described by using an example in which image data subjected to spot color rendering is stored in a storage component inside an MFP102equipped with a spot color toner, and the image data is printed out by another MFP103equipped with no spot color toner (hereinafter, in this specification, the MFP102equipped with the spot color toner and having a spot color printing function will be simply referred to as an “equipped MFP102” whereas the MFP103equipped with no spot color toner and having no spot color printing function will be referred to as a “non-equipped MFP103”).

In addition to the above-described case, the present invention is also applicable to an aspect in which image data containing spot color data is generated by an information processing device, sent from the information processing device to an MFP, and then printed out.

Note that techniques for compressing and decompressing image data described in this specification are not particularly limited, and it is possible to use publicly-known techniques such as the JPEG format.

Moreover, a spot color toner herein means a toner other than conventional color toners used for four-color printing. Such a spot color toner may be a “transparent toner” or a “light-color toner”, for example. In the embodiment 1, the transparent color is used as spot color.

FIG. 1is a block diagram showing an example of a network printing system using an image forming apparatus.

The equipped MFP102, the non-equipped MFP103, and a host computer101are connected to a LAN104built in an office10. The equipped MFP102and the non-equipped MFP103are able to interpret a page description language (hereinafter referred to as a PDL) transmitted from the host computer101through the PLAN104and to print out rendered image data. Moreover, the image data stored in a storage component inside the equipped MFP102can be transmitted to the non-equipped MFP103through the LAN104and printed by using the non-equipped MFP103.

FIG. 2is a view showing a configuration of the host computer101.

Image data will be described by using an example in which the image data is generated by using a spot color provided in an application201(such data will be hereinafter referred to as “application data”). After receiving an instruction from a user to store the application data in the storage component inside the MFP, a printer driver user interface (UI) component202notifies a printer driver203of the instruction. The printer driver203converts the application data into PDL data. Examples of the PDL include LIPS and PS, for example. After the PDL data thus generated is sent to a transmitting component204, the PDL data is transmitted to the equipped MFP102.

FIG. 3is a view showing a configuration of each MFP, which includes a PDL processing component301, a storage processing component302, a storage component303, a UI component304, an image processing component305, a printing component306, and an output processing component307.

FIG. 4is a view showing a configuration of the PDL processing component301inFIG. 3, which includes a receiving component401, a preliminary analyzing component402, a spot color-four color converting component403, a PDL analyzing component404, an intermediate language developing component405, a compression processing component406, and a transmitting component407.

FIG. 6is a view showing a configuration of the storage processing component302inFIG. 3, which includes a decompression processing component601, a storage job information receiving/analyzing component602, a difference extraction processing component603, a compression processing component604, a transmitting component605, and a difference information adding component606.

FIG. 7is a view showing a configuration of the output processing component307inFIG. 3, which includes a decompression processing component701, an output job information receiving/analyzing component702, a difference information restoring component703, a compression processing component704, and a transmitting component705.

FIG. 10is a view showing a configuration of the image processing component305inFIG. 3, which includes a decompression processing component1001, a color processing component1002, an image formation processing component1003, and a transmitting component1004.

FIG. 5,FIG. 8,FIG. 9, andFIG. 11are flowcharts for explaining outlines of processing to be executed by the respective components constituting the image forming apparatus according to Embodiment 1. Specifically,FIGS. 5,8,9, and11correspond to the PDL processing component301, the storage processing component302, the output processing component307, and the image processing component305, respectively.

FIG. 22shows an example of a screen to be displayed on a panel screen of the UI component304as a user interface. This embodiment will be described below on the assumption that the PDL data transmitted from the transmitting component204of the host computer is received by the receiving component401in the PDL processing component301of the equipped MFP102.

(Description of PDL Processing Component)

Now, the PDL processing component301of the equipped MFP102will be described with reference toFIG. 4showing the configuration thereof andFIG. 5showing the process flow thereof.

First, from header information of the PDL data, the preliminary analyzing component402collects information required for determining whether or not it is necessary to subject the received PDL data to spot color process (S501).

Then, based on the information collected from the header information, determination is made as to whether or not it is necessary to perform the spot color process (S502). If the determination result shows that the spot color process is necessary, the processing proceeds to step S503. In step S503, the PDL analyzing component404performs a spot color PDL data analysis on the PDL data and generates an intermediate language (spot color intermediate data).

Next, in step S504, the intermediate language developing component405renders the intermediate language (the spot color intermediate data) and generates spot color image data. The spot color image data is composed of transparent data and CMYK data. The compression processing component406compresses the spot color image data thus generated and generates compressed spot color data (S505).

Next, in step S506, the spot color-four color converting component403converts spot color data into four-color data. The four-color data is composed of CMYK data. This conversion process is executed by using a spot color-four color lookup table which is registered in advance so as to generate four-color PDL data.

Then, in step S507, the PDL analyzing component404analyzes the four-color PDL data and generates an intermediate language (four-color intermediate data).

Next, in step S508, the intermediate language developing component405renders the intermediate language (the four-color intermediate data) and generates four-color image data. The compression processing component406compresses the four-color image data thus generated and generates compressed four-color data (S509).

Then, the compressed spot color data and the compressed four-color data are transmitted from the transmitting component407toward the decompression processing component601in the storage processing component302of the equipped MFP102(S510). Moreover, information on whether or not it is necessary to perform the spot color process is transmitted, as job information, toward the storage job information receiving/analyzing component602in the storage processing component302of the equipped MFP102.

If the spot color process is determined to be unnecessary in the previous step S502, the processing proceeds from step S502to step S507and then the processes from step S507to step S510are sequentially executed. Specifically, the four-color intermediate data are generated by analyzing the received four-color PDL data (S507), and then the four-color intermediate data are rendered (S509) and compressed (S509). Thereafter, the compressed four-color data are transmitted to the storage processing component302(S510).

(Description of Storage Processing Component)

Next, the storage processing component302of the equipped MFP102will be described with reference toFIG. 6showing the configuration thereof andFIG. 8showing the process flow thereof.

The storage processing component302of the equipped MFP102is a module configured to execute processing which becomes necessary when the compressed data generated by the PDL processing component301is to be saved and stored in the storage component303.

In this processing, the storage job information receiving/analyzing component602first determines whether or not the data to be processed from now contains the compressed spot color data (S801). If the compressed spot color data is determined to be present, the decompression processing component601decompresses both of the compressed spot color data and the compressed four-color data, and acquires the spot color image data and the four-color image data (S802).

Next, by using both types of the image data, the difference extraction processing component603extracts a difference between pixel value of each toner of a CMYK version of the spot color image data and the corresponding pixel value in the four-color image data (S803). Based on difference information thus extracted, the difference information adding component606adds this difference information to the spot color image data (S804).

Here, in step S804, the addition of the difference information may be performed on all the pixels or only pixels showing spot colors. By providing the difference information to the four-color image data only for the pixels showing spot color, it is possible to minimize an increase in the storage size of the image data.

Next, in step S805, the compression processing component604compresses the spot color image data together with the difference information and thereby generates the compressed spot color data. Here, the four-color image data is no longer needed and therefore discarded.

Lastly, the transmitting component605transmits the generated compressed spot color data to the storage component303of the equipped MFP102(S806).

If the compressed spot color data are not present in step S801, the transmitting component605transmits the compressed four-color data to the storage component303of the equipped MFP102as it is, that is, without executing any process on the compressed four-color data, the compressed four-color data having been received from the PDL processing component.

The data subjected to the above-described processes is saved and stored in the storage component303.

(Description of Output Processing Component)

Next, the output processing component307of the equipped MFP102will be described with reference toFIG. 7showing the configuration thereof,FIG. 9showing the process flow thereof, and alsoFIG. 22showing an example of the panel screen of the MFP.

The output processing component307of the equipped MFP102is a module configured to execute processing which becomes necessary when the compressed data stored in the storage component303of the equipped MFP102is to be printed out by a different MFP.

In this processing, the user first selects a job stored in the storage component303from a stored document list2201(FIG. 22) on the panel screen. Subsequently, when the user selects which MFP to be used for printing from a print destination list2202(FIG. 22), information on the selected job and the print destination is transmitted to the storage component303.

In this embodiment, descriptions will be first provided for a case where the print destination selected by the user is the non-equipped MFP103, and then for a case where the print destination selected by the user is the equipped MFP102.

First, upon receipt of the information from the UI component304, the storage component303transmits the job selected from the stored document list2201by the user to the output processing component307.

Then, the output job information receiving/analyzing component702of the output processing component307determines whether the MFP selected as the output destination is the non-equipped MFP103not having the spot color printing function or the equipped MFP102having the spot color printing function and using a spot color toner (S901). As described above, when printing the job by the different image forming apparatus through the network, determination is made as to whether or not the different image forming apparatus has the spot color printing function. If the determination result shows that the print output destination is the non-equipped MFP103that cannot perform spot color printing, the processing proceeds to step S902.

In step S902, the decompression processing component701decompresses the compressed spot color data of the job and transmits the spot color image data and the difference information obtained by this decompression to the difference information restoring component703. The difference information restoring component703discards the unnecessary spot color version data from the spot color image data because the output destination is the non-equipped MFP (S903).

Then, in step S904, the four-color image data are restored by adding the pixel values in the difference information respectively to the pixel values of the four-color data (CMYK version) that remain after the spot color version of the data is discarded. The four-color image data can be reproduced into an optimum image even when the non-located MFP103compatible with the four-color output is used for the printing out, because the pixel values in the difference information are added to the four-color image data.

For example, when the spot color is “transparent”, glossiness, which can be reproduced by using a transparent toner, can be reproduced by increasing overall amounts of color toners of CMYK or slowing down a fixation speed of a printer engine.

Thereafter, the compression processing component704compresses the restored four-color image data and thereby generates the compressed four-color data (S905).

Lastly, the transmitting component7105transmits the generated compressed four-color data to the decompression processing component1001in the image processing component305of the non-equipped MFP103(S909).

When the output job information receiving/analyzing component702determines in step S901that the print output destination is the equipped MFP102having the spot color printing function, decompression process similar to step S902is executed (S906) and then the difference information restoring component703discards only the difference information (S907).

Thereafter, the compression processing component704compresses the spot color image data after discarding the difference information and thereby generates the compressed spot color data (S905).

Lastly, the transmitting component705transmits the generated compressed spot color data to the decompression processing component1001in the image processing component305of the equipped MFP102(S908).

(Description of Image Processing Component)

Next, the image processing component305of the non-equipped MFP103which receives the compressed four-color image data (the compressed four-color data) from the output processing component307of the equipped MFP102will be described with reference toFIG. 10showing the configuration thereof andFIG. 11showing the process flow thereof.

The image processing component305of the non-equipped MFP103includes the decompression processing component1001, the color processing component1002, the image formation processing component1003, and the transmitting component1004.

First, the decompression processing component1001decompresses the compressed four-color data in step S1101.

Next, the color processing component1002executes a color process on the four-color image data obtained by the decompression, the color process including the providing of an optimum gamma characteristic for the printing out by the non-equipped MFP or the adjusting of color densities (S1102), and the like.

Next, the image formation processing component1003executes an image formation process such as a screen process or an error diffusion process (S1103).

Then, the transmitting component1004transmits print data subjected to the image formation process to the printing component306(S1104).

Upon receipt of the print data, the printing component306of the MFP103performs printing in the four colors of CMYK based on the print data.

Next, the processing of the image processing component305of the equipped MFP102in the case of selecting the equipped MFP102as the print destination will be briefly described.

The processing by the image processing component305of the equipped MFP102is basically the same except not only the four-color image data is subjected to the processes such as ones performed by the image processing component305of the non-equipped MFP103described above, but also the spot color version of the data is also subjected to the processes. Specifically, the color processing component1002executes the color process while the image formation processing component1003executes the image formation process on both of the four-color image data and the spot color version of the data. Moreover, the transmitting component1004transmits the print data subjected to the image formation process, to the printing component306, and the printing component306performs printing for the CMYK version and the spot color version in accordance with the print data.

As described above, in Embodiment 1, when the image data subjected to rendering for the spot color is stored in the equipped MFP102, the image data is compared with the result of rendering for the four colors, and then the difference between each pixel value of the CMYK version of the spot color image data and the corresponding pixel value of the four-color image data is extracted. Thereafter, the extracted difference is retained as the difference information together with the image data. In this way, even when the image data is to be printed out by using the printer not compatible with the spot color, it is possible to print the image data without troubles by using the difference information for a part where the spot color is used.

In Embodiment 1, in order to reproduce a natural print image by printing spot color image data with the four colors of CMYK, only the pixel values of the CMYK version of the spot color image data are restored to the pixel values of the four color image data for four color printing.

Embodiment 2 is designed to be able to reproduce characteristics of the spot color toner as well. Here, Embodiment 2 will be described by using an example where the spot color toner is a tight magenta toner. A light magenta toner has a characteristic that it can reproduce a smooth highlighted part.

FIG. 12is a view showing a configuration of the image processing component305of the MFP illustrated inFIG. 3according to this embodiment, which includes the decompression processing component1001, the color processing component1002, the image formation processing component1003, the transmitting component1004, and a toner characteristic information analyzing component1201.

FIG. 13,FIG. 14, andFIG. 15are flowcharts for explaining outlines of processing to be executed by the respective components constituting the image forming apparatus of this embodiment. Specifically,FIGS. 13,14, and15corresponds to the storage processing component302, the output processing component307, and the image processing component305, respectively.

In Embodiment 2, descriptions will be first provided for the processing by the storage processing component302of the equipped MFP102in the case of storing compressed data in the storage component303of the equipped MFP102.

(Description of Storage Processing Component)

First, the storage job information receiving/analyzing component602in the storage processing component302determines whether or not the data to be subjected to a storing process from now contains the compressed spot color data (S1301).

When the compressed spot color data are determined to be present, the decompression processing component601decompresses the compressed spot color data and the compressed tour-color data and acquires the spot color image data and the four-color image data (S1302).

Next, by using both types of the image data, the difference extraction processing component603extracts the difference between each pixel value of the CMYK version of the spot color image data and the corresponding pixel value of the four-color image data (S1303). Moreover, the difference extraction processing component603also extracts information as to which type of the toner is used and adds the spot color toner type information to the difference information (S1304). In this embodiment, since the spot color toner is the light magenta toner, the information indicating the light magenta toner is added.

The difference information adding component606adds the difference information thus extracted to the spot color image data (S1305).

Next, in step S1306, the compression processing component604compresses the spot color image data and the difference information and thereby generates the compressed spot color data. At this time, the four-color image data are discarded.

Lastly, the transmitting component605transmits the generated spot color compressed data to the storage component303of the equipped MFP102(S1307).

When the compressed spot color data are not present in step S1301, the processing proceeds to step S1307where the transmitting component605transmits the compressed four-color data to the storage component303of the equipped MFP102as it is, that is, without executing any process on the compressed four-color data.

(Description of Output Processing Component)

Next, processing in the case of printing out the image data stored in the storage component303of the equipped MFP102by using the different MFP will be described with reference to the flowchart inFIG. 14.

Here, of the steps shown in the flowchart ofFIG. 14, detailed description will be omitted for steps common to the steps in the flowchart ofFIG. 9of the above-described Embodiment 1.

First, a user selects a job stored in the storage component303of the equipped MFP102from a stored document list. Subsequently, when the user selects which MFP to be used for printing from a print destination list, information on the selected job and the print destination is transmitted to the storage component303.

As similar to Embodiment 1, in this embodiment, descriptions will be first provided for the case where the print destination is the non-equipped MFP103, and then for the case where the print destination is the equipped MFP102.

Contents of steps S1401to S1404inFIG. 14are the same as the above-described contents of steps S901to S904inFIG. 9, which will be briefly described below. First, determination is made as to whether or not the printing out is to be performed by using the equipped MFP102having the spot color printing function (S1401). If it is determined that the printing is to be performed by using the non-equipped MFP103not having the spot color printing function, the compressed spot color data is decompressed by the decompression processing component701(S1402) and the spot color image data and the difference information obtained by the decompression are transmitted to the difference information restoring component703(S1403). The difference information restoring component703discards the data of the spot color version of the spot color image data (S1403) and restores the four-color image data by adding each pixel value in the difference information to the corresponding pixel value of the four-color data (S1404).

Moreover, in this embodiment, the difference information restoring component703extracts the information on the type of the spot color toner from the difference information and generates spot color toner information (S1405).

Then, the compression processing component704subjects the restored four-color image data and the spot color information to the compression process and thereby generates the compressed four-color data (S1406).

The transmitting component705transmits the compressed four-color data which included the compressed data of four-color image data and the compressed data of spot color information to the decompression processing component1001in the image processing component305of the non-equipped MFP103(S1409).

If it is determined that the printing out is to be performed by using the equipped MFP102, the decompression process is performed (S1407) and then the difference information is discarded from the spot color image data by the difference information restoring component703(S1408). Thereafter, the spot color image data after discarding the difference information are compressed by the compression processing component704to generate the compressed spot color data (S1406). The compressed spot color data is then transmitted from the transmitting component705to the decompression processing component1001(S1409).

(Description of Image Processing Component)

Next, the image processing component305of the non-equipped MFP103will be described with reference toFIG. 15. Here as well, detailed description will be omitted for processes in the flowchart ofFIG. 15which are common to those in the flowchart ofFIG. 11in the above-described Embodiment 1.

First, the four-color compressed data are decompressed by the decompression processing component1001(S1501).

Then, the toner characteristic information analyzing component1201determines whether or not the decompressed information has the spot color toner information in addition to the four-color image data (S1502).

As a result, if the decompressed information has the spot color toner information, the toner characteristic information analyzing component1201determines a content of the image process for achieving a visual effect of the spot color toner by using the spot color toner information, and creates an image processing coefficient (S1503). Regarding the content of this image process, the image process to be carried out is associated with each type of the spot color toner in advance. Accordingly, the content of the image process corresponding to the specified spot color toner is determined when the spot color toner is specified by the spot color toner information. For example, in this embodiment, the spot color toner is the light magenta toner, whose visual characteristic usually is smoothness. Therefore, the light magenta toner is associated in advance with a stronger smoothing process than a normal case.

Meanwhile, when the spot color toner is a “transparent toner”, a visual characteristic of the transparent toner is usually glossiness. For this reasons as described previously, overall amounts of the color toners are increased or a fixation speed of a printer engine is slowed down when the spot color toner is the transparent toner, for example. As described above, the toner characteristic information analyzing component1201issues an instruction to the image formation processing component1003in accordance with the content of the preset image process. In this embodiment, an instruction corresponding to the light magenta toner, i.e., an instruction to perform the smoothing process that is stronger than a normal case, is issued.

The rest of the processing is substantially the same as the processing starting from step S1102inFIG. 11.

Specifically, the color processing component1002executes the color process such as providing the optimum gamma characteristic or adjusting the color densities (S1504). Then, the image formation processing component1003executes the image formation process such as a screen process or an error diffusion process (S1505), and also executes a smoothing process based on the instruction from the toner characteristic information analyzing component1201. Thereafter, the print data subjected to the image formation process is transmitted from the transmitting component1004to the printing component306(S1506).

Upon receipt of the data, the printing component306of the non-equipped MFP103prints, in the four colors of CMYK, the print data subjected to the image formation process.

The image processing component305of the MFP102is the same as that in Embodiment 1 and explanation thereof will be thus omitted.

As described above, according to Embodiment 2, it is possible to reproduce the visual characteristic of the spot color toner in addition to the contents of Embodiment 1.

While Embodiments 1 and 2 use the image data containing the spot color version of data, Embodiment 3 always use the CMYK version of the four-color image data.

FIG. 16is a view showing a configuration of the PDL processing component301inFIG. 3of this embodiment, which includes the receiving component401, the preliminary analyzing component402, the PDL analyzing component404, the intermediate language developing component105, the compression processing component406, the transmitting component407, and a spot color toner print position information generating component1601.

FIG. 17is a view showing a configuration of the output processing component307inFIG. 3of this embodiment, which includes the decompression processing component701, the output job information receiving/analyzing component702, the difference information restoring component703, the compression processing component704, the transmitting component705, and a spot color toner print information processing component1701.

FIG. 18is a view showing a configuration of the image processing component305inFIG. 3of this embodiment, which includes the decompression processing component1001, the color processing component1002, the image formation processing component1003, the transmitting component1004, the toner characteristic information analyzing component1201, and a spot color generating component1801.

FIG. 19,FIG. 20, andFIG. 21are flowcharts for explaining outlines of processing to be executed by the respective components constituting the image forming apparatus according to this embodiment. Specifically,FIGS. 19,20, and21corresponds to the PDL processing component301, the output processing component307, and the image processing component305, respectively.

FIG. 23shows an example of a screen to be displayed on a screen of the host computer101. This embodiment will also be described below on the assumption that the PDL data transmitted from the transmitting component204of the host computer is received by the received401in the PDL processing component301of the equipped MFP102.

First, the PDL processing component301of the equipped MFP102will be described with reference toFIG. 16showing the configuration thereof andFIG. 19showing the process flow thereof.

(Description of PDL Processing Component)

Steps S1901and S1902are the same as the above-described steps S201and S502inFIG. 5, which will be briefly described below. The preliminary analyzing component402collects the information required for determining whether or not it is necessary to subject the received PDL data to the spot color process (S1901), and determination is made, based on the information, as to whether or not it is necessary to perform the spot color process (S1902).

If the spot color process is determined to be necessary, user's designation of an image design (see reference numeral2301inFIG. 23) for the printing in the spot color version is inputted next (S1903). The user's designation is performed by way of, for example, the panel screen which serves as the user interface and is provided to the UI component304of the equipped MFP102receiving various instructions from the user.

In this way, information on the designated image design is transmitted to the spot color toner print position information generating component1601through the UI component304of the equipped MFP102(illustration of this process is omitted in the flowchart inFIG. 19).

Then, based on the image design designated by the user, the spot color toner print position information generating component1601generates binary spot color toner print position information which defines a pixel where the spot color toner is used for the printing as “1” and defines a pixel where the spot color toner is not used for the printing as “0” (S1904).

Steps S1905and S1906are the same as the above-described steps S507and S508inFIG. 5, which will be briefly described below. The PDL analyzing component404analyzes the four-color PDL data and generates the intermediate language (the four-color intermediate data) (S1905). Subsequently, the intermediate language developing component405renders the intermediate language and generates the four-color image data (S1906).

Then, the compression processing component406compresses the four-color image data together with the spot color toner print position information and generates the compressed four-color data (S1907).

Then, the transmitting component407transmits the compressed four-color data to the decompression processing component601of the storage processing component302(S1908). Moreover, as the job information, the information as to whether or not it is necessary to perform the spot color process is transmitted to the storage job information receiving/analyzing component602of the storage processing component302.

In this embodiment as well, as similar to Embodiment 2, the spot color toner type information is added to the compressed four-color data by the storage processing component302in the equipped MFP102. The compressed four-color data is then stored in the storage component303inside the equipped MFP102. Specifically, the information on the type of the spot color toner used is extracted by the difference extraction processing component603in the storage processing component302, and the four-color image data after the spot color toner type information is added as the difference information is stored in the storage component303.

If the preliminary analyzing component402determines that the spot color process is not necessary in step S1902, only the four-color data are subjected to the processes in step S1905to step S1908.

(Description of Output Processing Component)

Next, the processing in the case of printing out the image data stored in the storage component303of the equipped MFP102by using a different MFP will be described with reference to a flowchart inFIG. 20.

In this embodiment as well, as similar to Embodiment 1 and 2, descriptions will be first provided for the case where the print destination is the non-equipped MFP103, and then for the case where the print destination is the equipped MFP102.

First, upon receipt of the information from the UI component304of the equipped MFP102, the storage component303of the equipped MFP102transmits the job selected from the stored document list2201to the output processing component307.

Then, the output job information receiving/analyzing component702of the output processing component307determines whether or not the received job is to be printed out by the non-equipped MFP103or the equipped MFP102(S2001).

If the result shows that the printing out is to be performed by the non-equipped MFP103, the decompression processing component701decompresses the compressed four-color data (S2002) and transmits the spot color toner print position information obtained by the decompression, to the spot color print information processing component1701. Subsequently, the spot color print information processing component1701discards the spot color print position information (S2003).

Then, the compression processing component704compresses the four-color image data and the spot color toner type information and generates the compressed four-color data (S2004).

Lastly, the transmitting component705transmits the generated compressed four-color data to the decompression processing component1001in the image processing component305of the non-equipped MFP103(S2005).

If the output job information receiving/analyzing component702determines in step S2001that the printing out is to be performed by the equipped MFP102, the processing proceeds to step S2005where the transmitting component705transmits the compressed four-color data to the image processing component305of the equipped MFP102.

(Description of Image Processing Component)

Next, the image processing component305of the non-equipped MFP103will be described. Meanwhile, the processing by the image processing component305includes the similar operations to those in Embodiment 2. Thus, the description of those operations will be omitted. The image processing component305of the equipped MFP102will be described with reference to a flowchart inFIG. 21.

First, upon receipt of the compressed four-color data, the image processing component305of the equipped MFP102decompresses the compressed four-color data by using the decompression processing component1001(S2101).

Then, on the four-color image data obtained by the decompression, the color processing component1002performs the color process as previously described in Embodiment 1 and 2 (S2102).

Then, by using a four-dimensional lookup table, the spot color generating component1801subjects the image data after completion of the color process to a spot color generation process so as to generate a spot color toner printing amount (S2103). This spot color generation process is performed using the spot color toner print position information. Specifically, the spot color toner printing amount is generated for each pixel having the value “1” in this information whereas no process is performed on each pixel having the value “0” in this information.

Subsequently, the image formation processing component1003performs the image formation process as previously described in Embodiment 1 and 2 (S2104).

Then, the transmitting component1004transmits the print data subjected to the image formation process, to the printing component306(S2105).

Upon receipt of the print data, the printing component306of the equipped MFP102performs printing of the CMYK and spot color versions in accordance with the print data.

As described above, Embodiment 3 does not use the spot color image data. Accordingly, it is possible to further reduce the volume of the image data as compared to Embodiment 1.

Other Embodiments

As has been described, the MFP having the spot color printing function explained in the embodiments of the present invention is assumed to be used as part of a network printing system in which the MFP is mutually connected to one or more MFPs not having the spot color printing function, through a network. Moreover, the present invention can also be grasped as the invention of a method of controlling each of the processes executed by the MFPs.

This application claims the benefit of Japanese Patent Application No. 2008-216918, filed Aug. 26, 2008, which is hereby incorporated by reference herein in its entirety.