Abstract:
A method and apparatus of adjusting color conversion parameters to be used by a color printer for printing documents or images, includes receiving a user input designating a color conversion parameter to be adjusted. It also includes obtaining information as to at least one other color conversion parameter that is related to the user designated color conversion parameter. It further includes adjusting the user designated color conversion parameter based on a user selection of source color-to-destination color change, and adjusting the at least one other color conversion parameter related to the user designated color conversion parameter based on the same user selection of source color-to-destination color change.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to a multi-function peripheral (MFP) and a method for copying a document, more particularly, to an apparatus and method of changing color adjustment parameters. 
     BACKGROUND OF THE INVENTION 
     In a conventional copier or MFP or image forming apparatus (hereinafter, for ease, collectively referred to as “copier”), when a user wants to print a document or an image in color, the user sends, by way of a personal computer (PC)  100 , a postscript file (e.g., PDL) to a color printer  110 , as seen in  FIG. 1 . The color printer  110  includes a PDL interpreter  120 , which converts the PDL file to Red/Green/Blue (RGB) bitmap image. A color conversion unit  130  converts the RBG bitmap image to Cyan/Magenta/Yellow/Black (CMYK) data, whereby this conversion is done by using information provided by a color conversion parameter storage  140 . In particular, the color conversion parameter storage  140  provides a color conversion parameter (CCP) to the color conversion unit  130 . The color conversion unit  130  outputs the CMYK data to a printing engine  150 , which prints the document or image in color, and which provides a hard copy for the user. 
       FIG. 2  shows, in further detail, the color conversion parameter storage  140 . The color conversion parameter storage  140  stores a plurality of color conversion parameters, such as CCP 1 , CCP 2 , CCP 3 , . . . , CCPn, whereby the color conversion parameter storage  140  is typically implemented as a color table. The color printer  110  has many different versions of color conversion parameters that are stored in the color conversion parameter storage  140 . A CCP is selected from the color conversion parameter storage  140  based on one or more of the following exemplary parameters: color mode, print resolution, halftone processing, and paper type used. Based on those inputs, the proper color conversion parameter (e.g., CCP 3 ) is output by the color conversion parameter storage  140  to the color conversion unit  130 . 
       FIG. 3  shows contents of a 3-dimensional lookup table (3-D LUT)  300  that may be implemented in the color conversion parameter storage  140 . The LUT  300  includes L*a*b* data that corresponds to ‘addresses’ in the LUT  300 , and CMYK data that corresponds to the ‘data’ in the LUT  300 . Based on the LUT  300 , L*a*b* is converted to CMYK data. L*a*b* data corresponds to the output color, and is a device independent color space. CMYK data corresponds to an amount of actual colors (cyan, magenta, yellow, black) to be printed on a sheet of paper. 
       FIG. 4  shows details of the color conversion unit  130 . The color conversion unit  130  includes an RGB-to-L*a*b* conversion unit  410 , which outputs L*a*b* data. This conversion is typically done using standard conversion equations or by using a Lookup Table. The color conversion unit  130  also includes a L*a*b*-to-CMYK conversion unit  420 , which may be implemented by way of the 3-D LUT  300  shown in  FIG. 3 . The L*a*b*-to-CMYK conversion unit  420  is provided with a color conversion parameter (CCP) that is output from the color conversion parameter storage  140 , and whereby the L*a*b*-to-CMYK conversion unit  420  outputs CMYK data to a printing engine (not shown, but see  FIG. 1 ). 
       FIG. 5  shows a 3-D L*a*b* space  500 , in order to show how a color conversion table can be used to perform an interpolation so as to obtain an accurate CMYK data value from an input L*a*b* data value. If an input L*a*b* value is stored in the 3-D LUT  300 , then the CMYK value corresponding to the input L*a*b* value is obtained directly from the 3-D LUT  300 . However, if the input L*a*b* value is not currently stored in the 3-D LUT  300 , then an interpolation can be performed in order to obtain the CMYK value that corresponds to the input L*a*b* value. As shown in  FIG. 5 , an eight-point interpolation is performed in order to extract the eight neighboring points for an input L*a*b* value, whereby a standard interpolation provides the proper CMYK value. 
       FIG. 6  shows a conventional color conversion parameter adjustment system  600 . In order to adjust a color conversion parameter (CCP), an application (not shown) on a user&#39;s PC  610  is utilized. A user determines a source color and a destination color, and a color conversion parameter (e.g., CCP 1 ) corresponding to the source and destination colors is determined by the application. A CCP is downloaded to the user&#39;s PC  610  from the color conversion parameter storage  140  of the color printer  110  to a color adjustment means  620  of the user&#39;s PC  610 , and the user edits the CCP. In particular, the user selects one CCP to adjust, and that CCP is downloaded to the user&#39;s PC  610 . 
     Referring now to  FIG. 7A , in the source/destination color selection process, a user chooses a color to adjust from a source color display. In  FIG. 7A , a scanned image is provided as a display image  710  on the user&#39;s PC  610 , whereby the letter “A” is shown as having a light-red color on the user&#39;s display. The user changes that light-red color to a dark-red color, by performing an operation (e.g., mouse operation and/or keyboard operation, by selecting a destination color from a color palette provided on the display) on a pertinent area on the display (e.g., over the letter “A” region on the display). This is done in order to obtain a desired destination color, as shown in the display image  720  of  FIG. 7B , whereby the letter “A” is now provided as a darker red color than the letter “A” in  FIG. 7A . The color adjustment means  620  changes the CCP provided to it by the color printer  110  in accordance with the source/destination color changes made by the user, and the adjusted CCP is output to the color conversion parameter storage  140  of the color printer  110 , whereby it is stored as a new CCP value. 
     A problem exists in the conventional CCP adjustment process in that a user can only adjust one CCP at a time. If a user desires to adjust two or more CCPs, the entire CCP adjustment process must repeat the download/edit/upload process for each CCP being adjusted. With printers having numerous CCPs, this can become a very time consuming process. 
     Accordingly, there exists a desire to allow for a plurality of CCPs to be adjusted in a more expedient manner. 
     SUMMARY OF THE INVENTION 
     According to an aspect of the invention, a method of adjusting a plurality of color conversion parameters includes receiving a user input designating a color conversion parameter to be adjusted. The method also includes obtaining information as to at least one other color conversion parameter that is related to the user designated color conversion parameter. The method further includes adjusting the user designated color conversion parameter based on a user selection of source color-to-destination color change, and adjusting the at least one other color conversion parameter related to the user designated color conversion parameter based on the same user selection of source color-to-destination color change. 
     According to another aspect of the invention, an image processing apparatus includes a color conversion designator that is configured to designate a color conversion parameter to be adjusted. The apparatus also includes a color conversion parameter list that is configured to store information concerning color conversion parameters that are related to each other, and that is configured to output related color conversion parameters to the selected color conversion parameter when the selected color conversion parameter is input thereto. The apparatus further includes a color adjustment unit that is configured to receive the selected color conversion parameter and at least one related color conversion parameter to the selected color conversion parameter, and that is configured to receive a user input corresponding to a source color-to-destination color change. The color adjustment unit adjusts the selected color conversion parameter and the at least one related color conversion parameter based on the source color-to-destination color change. 
     According to yet another aspect of the invention, there is provided a program product for adjusting color conversion parameters to be used by a color printer, the program product including machine-readable program code for causing, when executed, one or more machines to perform the step of receiving a user input designating a color conversion parameter to be adjusted. Also, there is performed the step of obtaining information as to at least one other color conversion parameter that is related to the user designated color conversion parameter. Further, there is performed the step of adjusting the user designated color conversion parameter based on a user selection of source color-to-destination color change, and adjusting the at least one other color conversion parameter related to the user designated color conversion parameter based on the same user selection of source color-to-destination color change. 
     Further features, aspects and advantages of the present invention will become apparent from the detailed description of preferred embodiments that follows, when considered together with the accompanying figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram showing color conversion adjustment parameter components of a conventional color printer; 
         FIG. 2  is a block diagram showing components of a color conversion parameter storage unit used by the conventional color printer shown in  FIG. 1 ; 
         FIG. 3  is a table that corresponds to a color conversion parameter table used by the conventional color printer shown in  FIG. 1 ; 
         FIG. 4  is a block diagram showing components of a color conversion unit used by the conventional color printer shown in  FIG. 1 ; 
         FIG. 5  is a vector space that shows how an L*a*b* value can be converted to a CMYK value by using a color conversion parameter table; 
         FIG. 6  is a block diagram showing components of a conventional color conversion parameter adjustment system; 
         FIG. 7A  is a display that can be used to select a source color; 
         FIG. 7B  is a display that can be used to select a destination color; 
         FIG. 8  is a block diagram showing components of a color conversion parameter adjustment system according to a first or second embodiment of the invention; 
         FIG. 9  is a table that corresponds to a color conversion parameter list used by the color conversion parameter adjustment system according to the first or second embodiments; 
         FIG. 10A  is a color conversion parameter table that is used by the color conversion parameter adjustment system according to the first or second embodiments; and 
         FIG. 10B  is an inverse color conversion parameter table that is used by the color conversion parameter adjustment system according to the first embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An aspect of the present invention provides for adjusting a plurality of color conversion parameters based on a selection of a single color conversion parameter to be adjusted. 
       FIG. 8  shows a color conversion parameter adjustment apparatus according to a first embodiment of the invention. The color adjustment apparatus includes a color conversion parameter adjustment application  810  that runs on a client&#39;s PC  800 , and a color printer  820 . The color printer  820  includes an interpreter (e.g., PDL interpreter)  830 , a color conversion unit  835 , a printing engine  840 , a color conversion parameter list  845 , and a color conversion parameter storage  850 . The application  810  includes a buffer  855 , a color conversion parameter selector  860 , and a color adjustment unit  865 . 
     The client&#39;s PC  800  provides a postscript file (e.g., PDL) to the interpreter  830 , whereby the interpreter  830  converts the postscript file to RGB data. The RGB data is provided to the color conversion unit  835 , which converts the RGB data into CMYK data. The CMYK data is provided to a printing engine  840 , which prints an image onto a sheet of paper to thereby provide a hard copy output. The color conversion parameter storage  850  provides a color conversion parameter (CCP) to the color conversion unit  835 , so that the color conversion unit  835  can perform the correct RGB-to-CMYK conversion. 
     The color conversion selector  860  inputs a color conversion parameter (e.g., CCP 1 ) selected by a user, and queries the color conversion parameter list  845  for all color conversion parameters (e.g., CCPX, CCPY, CCPZ) related to the selected color conversion parameter. The related color conversion parameter names are output from the color conversion parameter list  845  to the color conversion selector  860 , whereby the color conversion selector  860  provides the name of the selected color conversion parameter as well as the names of all of the related color conversion parameters, to the color adjustment unit  865 . The buffer  855  receives a source color-to-destination color user setting, and provides such information to the color adjustment unit  865 . The color adjustment unit  865  requests the actual selected color conversion parameter and the actual related color conversion parameters from the color conversion parameter storage  850 , based on names of those color conversion parameters provided to the color conversion parameter storage  850 . Based on those inputs, the color adjustment unit  865  adjusts the input color conversion parameters according to the user&#39;s selection, and outputs the adjusted color conversion parameters to be stored in the color conversion parameter storage  850 . 
     By way of the first embodiment, a user can adjust several CCPs automatically, by choosing one CCP and having the apparatus automatically determine all related CCPs to be adjusted automatically in accordance with the adjusted CCP. In more detail, a user chooses a CCP, e.g., CCP 1 . The color conversion selector  860  requests a lists of related CCPs from the color conversion parameter list  845 , and the color conversion parameter list  845  provides a list of related CCPs to the color conversion selector  860 . That information is preferably stored in a table in the color conversion parameter list  845 . Another possible implementation is allowing the user to define or select the related CCPs for adjustment, such as by presenting a menu or the like to the user. 
     The color adjustment unit  865  requests the actual selected CCP (e.g., CCP 1 ) from the color conversion parameter storage  850 , and downloads the selected CCP from the color conversion parameter storage  850 . A user selects a source color and a destination color, similar to the manner shown and discussed with respect to  FIGS. 7A and 7B , whereby that information is temporarily stored in the buffer  855 , and then output to the color adjustment unit  865 . The color adjustment unit  865  adjusts the selected CCP based on the source color and destination color changes provided by way of the buffer  855 , and outputs the adjusted CCP to be then stored in the color conversion parameter storage  850 . Then, each of the related CCPs is adjusted sequentially, in an automatic manner, without any user intervention. When each CCP is adjusted by the color adjustment unit  865 , a regular L*a*b*-to-CMYK conversion table is downloaded from the color conversion parameter storage  850  for the corresponding CCP, whereby an inverse L*a*b*-to-CMYK conversion table may also be downloaded in one possible implementation (to be discussed in detail later). 
       FIG. 9  shows one possible implementation of the color conversion parameter list  845  that may be utilized in the first embodiment. The color conversion parameter list  845  corresponds to a table that stores information corresponding to: color mode, resolution, halftone, paper type, and color conversion parameter. There are shown three different types of color modes, namely “general”, “presentation”, and “photographic”, while one of ordinary skill in the art will recognize that other types of color modes may be stored in the color conversion parameter list  845  (e.g., desktop publishing, CAD, line art). 
     As seen in  FIG. 9 , color conversion parameters CCP 1 -CCP 6  are related as being CCPs used in the ‘general’ color mode. So, if a user selects one of these color conversion parameters to be adjusted, the other ones will be automatically adjusted in accordance with the first embodiment. Also, color conversion parameters CCP 7 -CCP 2  are shown as being related to each other, as all being CCPs used in the ‘presentation’ color mode. Thus, if a user adjusts CCP 9 , then CCP 7 , CCP 8 , CCP 10 , CCP 11  and CCP 12  will automatically be adjusted as well. Further, color conversion parameters CCP 13 -CCP 15  are shown as being related to each other, as all being CCPs used in the ‘photographic’ color mode. Thus, in  FIG. 9 , CCPs are related to each other based on their being in the same color mode. Other modes of relatedness (e.g., based on same resolution, or based on same half-tone type, or based on same paper type) may be envisioned while remaining within the spirit and scope of the invention. 
       FIG. 10A  shows an exemplary color conversion parameter  1  table  1010  and  FIG. 10B  shows an inverse color conversion parameter  1  table  1020  that are utilized by the color adjustment unit  865  in accordance with the first embodiment. In a first step, a source color address is selected from the color parameter  1  table  1010 , based on the user selected input color S(L*a*b*) in the input color-to-destination color adjustment. In a second step, an address (CMYK) of the inverse color conversion parameter table  1020  is searched corresponding to the destination color D(L*a*b*) selected by the user in the input color-to-destination color adjustment. In a third step, the address (CMYK) searched at the second step is set to the data of the address (L*a*b*) of the color conversion parameter, whereby the address (L*a*b*) is the address in the color conversion parameter table  1010  selected in the first step. 
     As an example, referring to  FIGS. 10A and 10B , assume that a L*a*b* 10, 0, 0 value is selected from the color conversion parameter table  1010 , which corresponds to the source color selected by the user. Now, the destination color selected by the user is converted to an L*a*b* value and is used to determine the corresponding CMYK value from the inverse color conversion parameter table  1020 . Thus, if the destination color corresponds to L 3 *a 3 *b 3 *=20, 0, 0, then the corresponding CMYK value of 0, 0, 0, 20 is obtained as the address for this L*a*b* value in the inverse color conversion parameter table  1020 . Then, the CMYK value of 0, 0, 0, 20 replaces the previous C 100 , M 100 , Y 100 , K 100  value stored for the L*a*b*=10, 0, 0 address in the color conversion parameter table  1010 . 
     Once the above has been performed for the selected CCP (e.g., CCP 1 ), the other related CCPs are automatically adjusted in a sequential manner, using the same methodology as described above. 
     A second embodiment for performing color conversion parameter adjustment will be explained herein, whereby only the color conversion parameter table  1010  of  FIG. 10A  is utilized. In a first step, an address (L*a*b*) of a selected CCP (e.g., CCP 1 ) is selected corresponding to the user-selected input color S(L*a*b*). In a second step, the color (CMYK) in the color conversion parameter table  1010  corresponding to the address selected in the first step is set to the destination color (CMYK) selected by the user. As an alternative implementation of the second embodiment, the destination color is changed from CMYK to L*a*b* data using the inverse color conversion parameter table  1020 . 
     The first embodiment provides for accurate color, in that the output color (e.g., L*a*b*) for the selected CCP and the related CCPs is the same, whereby the color output difference between a selected CCP and a related CCP may be a little different from each other. The second embodiment provides for pure color, in that the same color amounts (e.g., the amount of ink used during printing) are used for different types of printing, but whereby the output color on the page (e.g., the L*a*b*) may be different based on the print mode selected. 
     The foregoing description of a preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light in the above teachings or may be acquired from practice of the invention. The embodiments (which can be practiced separately or, where possible, in combination) were chosen and described in order to explain the principles of the invention and as practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.