System and method for creating print data

Abstract

A system for creating print data based on pixel data that includes a plurality of different ink or toner color values (C'M'Y'K') for a pixel. The system includes an ink or toner restriction module (40) configured to apply at least one scaling factor function (such as λCMYK, λCMY, λCM, etc.) to at least one color combination in order to limit the amount of ink or toner applied during printing, and each scaling factor function of the color combination determines a scaled color value (such as C''M''Y''K'', C''M''Y'', C''M'' etc.) based on a color value among the plurality of color values (such as C'M'Y'K', C'M'Y', C'M' etc.) associated with the color combination.

Description

Technical Field

[0001] The field of the present invention relates to systems and methods for creating print data. Certain embodiments relate to systems and methods for creating print data to limit the amount of liquid ink or toner applied during printing.

Background Art

[0002] When performing color printing with liquid ink or toner, it is known that problems may occur if too much ink or toner is applied during printing. One problem is known as "bleeding", where the ink / toner is overapplied and different colors may mix in an undesirable way. Another problem is known as "feathering", where the ink / toner meanders on or in the substrate and one color may meander into another. Also, when using curable ink / toner, if the ink / toner is overapplied, there is a risk that only the upper portion of the applied ink / toner will cure and the cure will not extend throughout the depth of the applied layer.

[0003] To avoid such problems, it is known to perform linear reduction or scaling of the source image data by reducing the ink volume of each pixel by a certain scaling factor (e.g., by multiplying each of the CMYK values of the pixel by a certain scaling factor).

[0004] Furthermore, it is known to perform color management when converting color values of an image file (e.g., from the CIELab color space) to a printing color space (e.g., the CMYK color space). More particularly, for example, it is known to perform color profiling of an image file using a lookup table. However, this makes it difficult to handle fine gradations. Also, since the required ink limitations usually depend on the type of ink / toner, the type of substrate, and / or other environmental conditions, it is desirable to be able to change / optimize the lookup table used. Creating such a lookup table requires many test patches, so this is a cumbersome process. Also, the final image to be printed may only be known during printing, for example, when a barcode has to be printed on top of the image from the image file. In such cases, the use of such a lookup table is not appropriate. SUMMARY OF THE INVENTION

[0005] An object of embodiments of the present invention is to provide a system and method for creating print data in an improved manner, thereby reducing bleeding and fringing problems.

[0006] According to a first aspect, a system for creating print data based on pixel data including a plurality of different ink or toner color values (C’M’Y’K’) for a pixel is provided. The system comprises an ink or toner limitation module. The ink or toner limitation module determines at least one scaling factor function (λ CMYK , λ CMY , λ CMconfigured to apply, etc.). Each scaling coefficient function of the color combination determines a scaled color value (such as C''M''Y''K'', C''M''Y'', C''M'' etc.) based on the color value among the plurality of color values (such as C'M'Y'K', C'M'Y', C'M' etc.) related to the color combination.

[0007] By applying the scaling coefficient function to a specific color combination, the limitation of the amount of ink / toner can be carried out more precisely and quickly. For example, there are applications where only the YK color combination can be the target of the scaling coefficient function, and there are also applications where multiple color combinations (such as (YK and CM and CY) or (OYK and CMYK) etc.) can be the target of the scaling coefficient function.

[0008] The scaling coefficient function is usually a function that defines the scaling coefficient as a function of the color values of a specific color combination. Therefore, this scaling coefficient is not a constant coefficient but a function of the color values of a specific color combination. For example, when the sum of the color values of that color combination increases or the maximum value of the color values of a specific color combination decreases, the scaling coefficient may decrease. Each scaling coefficient function of a certain color combination is preferably a continuous function of the color values related to each color combination.

[0009] Preferably, the system further includes a linearity compensation module arranged upstream of the ink or toner limitation module. The linearity compensation module applies a compensation coefficient function (λ C , λ M , λ Y , λ K) is applied to obtain a new color value (C’M’Y’K’), and the new color value (C’M’Y’K’) is configured to be output to an ink or toner limiting module, or an intermediate module between a linearity compensation module and an ink or toner limiting module. In other words, the ink or toner limiting module functions in a color combination, and the linearity compensation module performs scaling of individual colors.

[0010] Performing linearity compensation before the limitation of ink or toner in the manner described above has the advantage that very accurate limitations targeted at specific color combinations can be achieved. If the linearity compensation is performed after the ink limitation, the ink limitation is not so good. Also, performing linearity compensation before the limitation of ink or toner may simplify the calibration process used to determine the scaling coefficient function and the compensation coefficient function. See the details.

[0011] The compensation coefficient function is usually a function that defines the compensation coefficient in a function of a single color value. Therefore, this compensation coefficient is not a constant coefficient but a function of the color value. Each compensation coefficient function is preferably a continuous function of the color value.

[0012] Preferably, at least one color combination includes a plurality of color combinations. More preferably, the plurality of color combinations includes at least two different combinations of two colors (such as Y’K’, C’Y’, C’M’, etc.), and even more preferably, only includes combinations of two colors. The inventors have found that by targeting specific combinations of two colors, good results can be obtained without making the system overly complex.

[0013] The ink or toner limiting module is configured to apply at least two scaling coefficient functions to determine the scaled values of at least two color combinations, and for the colors appearing in two or more combinations, to use a function such as a minimum function or an average function or a weighted average function or a median function to determine the scaled color values to be output. For example, when color combinations CY, CM, CK, and YK are used and the function is a minimum function, the color values can be determined as C’’ = min(λ CY C’, λ CM C’, λ CK C’), M’’ = λ CM M’, Y’’ = λ YK Y’, K’’ = min(λ CK K’, λ YK K’).

[0014] The ink or toner limiting module is preferably configured to determine at least one input parameter (f1, f2) derived from the color values of the color combination for the color combination among the plurality of color combinations, and to use the at least one input parameter for the scaling coefficient function of the color combination. In other words, at least one input parameter is used to calculate the scaling coefficient used for a specific color combination.

[0015] The at least one input parameter preferably includes any one or a combination of the sum of the color values of the color combination, the weighted sum of the color values of the color combination, the maximum color value of the color values of the color combination, the minimum color value of the color values of the color combination, the average of the color values of the color combination, the weighted average of the color values of the color combination, and the median of the color values of the color combination.

[0016] The system preferably further comprises a color management module configured to receive an image file and generate, for each pixel of the image file, a plurality of ink or toner color values that are input to an ink or toner limiting module either directly or in a processed form. For example, the ink or toner limiting module can either use directly the values output from the color management module or first preprocess the values output from the color management module by means of a linearity compensation module and / or a merge module (see details). This can be any conventional color management module. For example, the color management module can convert color values from the CIELab color space to a color space for printing (e.g., the CMYK color space).

[0017] In an exemplary embodiment, the system further comprises a screening module configured to receive the scaled color values from the ink or toner limiting module and perform screening optionally based on the scaled color values. Screening can determine whether a pixel needs to be printed. Any suitable type of screening can be used in screening, such as stochastic or FM screening techniques, or cluster or AM screening techniques.

[0018] In an exemplary embodiment, the linearity compensation module is configured to apply a compensation coefficient to the pixels of a plurality of page elements and determine new color values for each page element. The system further comprises a merge module configured to receive the new color values of each page element, merge the color values of each pixel of the page element to obtain a merged new color value (C’M’Y’K’) for each pixel, and input the merged new color value (C’M’Y’K’) to the ink or toner limiting module.

[0019] In a typical embodiment, each page element includes, for each pixel, a color value (CMYK) and a transparency bit (T) indicating whether the pixel is transparent. In this case, the merge module determines a new merged color value considering the transparency bit.

[0020] In another exemplary embodiment, a color management module is configured to generate a plurality of page elements having color values for each pixel, and the system further includes a merge module configured to receive the color values of each page element and merge the color values of each pixel of the plurality of page elements to obtain a merged color value (CMYK) for each pixel. In this case, it is preferable that the linearity compensation module is configured to apply a compensation coefficient to the merged color value to obtain a new color value (C’M’Y’K’), and input the new color value to an ink or toner limitation module.

[0021] In another exemplary embodiment, an ink or toner limitation module is configured to receive a plurality of page elements and apply at least one scaling coefficient function to at least one color combination for each page element to obtain scaled color values (C’’M’’Y’’K’’, C’’M’’Y’’, C’’M’’, etc.) for each page element, and the system further includes a merge module configured to receive the scaled color values of each page element and merge the scaled color values of each pixel of the plurality of page elements to obtain a new merged color value for each pixel.

[0022] In another exemplary embodiment, the system further includes a merge module configured to receive an image file having a plurality of page elements, merge the plurality of page elements to obtain a merged image file, and input the merged image file to a color management module.

[0023] According to another aspect, a method for constructing a system according to any one of the embodiments disclosed above is provided. This method Optionally, using at least one associated pre-set scaling factor (λ CMYK0 、λ CMY0 、λ CM0 etc.), printing a first test patch with different color values for each color combination of the at least one color combination, Based on the printed first test patch, determining scaling values (λ CMYK 、λ CMY 、λ CM etc.) to be used with at least one scaling factor function (λ CMYK1 、λ CMY1 、λ CM1 etc.) of at least one color combination.

[0024] Therefore, the pre-set scaling factor can be set for each color combination. For example, when two colors are included in the color combination, the pre-set scaling factor can be 150 / 200, or when four colors are included in the color combination, the pre-set scaling factor can be 300 / 400. At least one pre-set scaling factor may be based on prior knowledge regarding the problem of ink coverage. It is also possible to start from zero without using any pre-set scaling factor (or with the pre-set scaling factor being 1).

[0025] In this case, the operator can manually analyze the first test patch and / or the first test patch can be analyzed in an automated manner, for example, using automated image interpretation, and the scaling values (λ CMYK1 、λ CMY1 、λ CM1etc.) can be determined based on analysis. The analysis usually includes evaluating the printing quality of different patches for artifacts such as edge fringing and bleeding, and evaluating the curing quality of different patches. This evaluation can be performed manually or by automatic image interpretation.

[0026] The scaling value is usually the scaling value used when all the color values of the color combination are 100%.

[0027] This method comprises, for each individual color, printing a plurality of second test patches with different color values for the individual color, the printing step of limiting the amount of ink or toner applied during printing using at least one scaling coefficient function (λ CMYK λ CMY λ CM etc.) having the determined scaling value, and determining, based on the second test patches, a compensation coefficient function (λ C λ M λ Y λ K ) for each individual color. It is further preferred to include.

[0028] For example, 15 to 30 second test patches can be printed for each individual color (the preset compensation coefficient is 1, i.e., no compensation), and the compensation function can be determined based on the second test patches.

[0029] Optionally, this method comprises using at least one scaling coefficient function (λ CMYK λ CMY λ CM etc.) determined together with the determined scaling value, and the determined compensation coefficient function (λ C λ M λ Y λ KThe steps of using

[0030] By using at least one scaling coefficient function determined together with the determined scaling value, the number of extra patches printed is reduced compared to prior art solutions that do not use such a scaling coefficient function. Since this function is usually a smooth continuous function, all or most patches are different in order to improve accuracy.

[0031] According to yet another aspect, a method for creating print data based on pixel data including a plurality of different ink or toner color values (C’M’Y’K’) for pixels is provided. This method is based on the color values (C’M’Y’K’), and at least one scaling coefficient function (λ CMYK , λ CMY , λ CM etc.) is applied to determine scaled color values (C’’M’’Y’’K’’, C’’M’’Y’’, C’’M’’ etc.) based on the color values among the plurality of color values (C’M’Y’K’, C’M’Y’, C’M’ etc.) related to the color combination, and includes the step of limiting the amount of ink or toner applied during printing.

[0032] For this method, the technical merits described above for the system are mutatis mutandis applicable.

[0033] This method, before applying the at least one scaling coefficient function, for pixels having a plurality of different color values (CMYK), applies a compensation coefficient function (λ C , λ M , λ Y , λ K ) to each color value of the plurality of color values to obtain new color values (C’M’Y’K’), and the at least one scaling coefficient function (λ CMYK , λ CMY, λ CM It is preferable to further include a step of using the new color value (C'M'Y'K') in a step of applying (such as).

[0034] The plurality of color combinations preferably include at least combinations of two colors (such as YK, CY, CM, etc.), and preferably include only combinations of two colors.

[0035] At least two scaling coefficient functions determine the scaled values of at least two color combinations, and for the colors appearing in two or more color combinations, functions such as the minimum function, average function, weighted average function, or median function are preferably applied to determine the output scaled color values. For example, when color combinations CY, CM, CK, and YK are used and the function is the minimum function, the color values can be determined as C'' = min(λ CY C', λ CM C', λ CK C'), M'' = λ CM M', Y'' = λ YK Y', K'' = min(λ CK K', λ YK K').

[0036] Optionally, this method further includes a step of deriving at least one input parameter (f1, f2) from the color values of the color combination for the color combination among the plurality of color combinations, and a step of using the at least one input parameter as an input to at least one scaling coefficient function. The at least one input parameter can include any one or a combination of the sum of the color values of the color combination, the weighted sum of the color values of the color combination, the maximum color value of the color values of the color combination, the minimum color value of the color values of the color combination, the average of the color values of the color combination, and the median of the color values of the color combination.

[0037] This method preferably further includes receiving an image file, and for each pixel of the image file, generating a plurality of ink or toner color values used in a further processed form, optionally, by applying at least one scaling factor function.

[0038] According to an exemplary embodiment, a compensation factor function is applied to the pixels of a plurality of page elements, and a new color value is determined for each page element. The method further includes merging the color values of the page elements to obtain a merged new color value (C’M’Y’K’) for each color, and using the merged new color value (C’M’Y’K’) in applying at least one scaling factor function.

[0039] In another exemplary embodiment, the method includes generating a plurality of page elements having color values for each pixel, and merging the color values of the plurality of page elements to obtain a merged color value (CMYK) for each pixel. In this case, the method preferably further includes applying a compensation factor function to the merged color value to obtain a new color value (C’M’Y’K’), and using the new color value (C’M’Y’K’) in applying at least one scaling factor function.

[0040] In another exemplary embodiment, the method includes applying at least one scaling factor function to at least one color combination for each page element to obtain a scaled color value (C’’M’’Y’’K’’, C’’M’’Y’’, C’’M’’, etc.) for each page element, and merging the scaled color values of each pixel of the plurality of page elements to obtain a merged new color value for each pixel.

[0041] In another exemplary embodiment, the method includes receiving an image file having a plurality of page elements, merging the plurality of page elements to obtain a merged image file, and for each pixel of the merged image file, using the merged image file to generate a plurality of ink or toner color values used in a further processed form optionally, by applying at least one scaling factor function.

[0042] According to a further aspect of the invention, there is provided a computer program comprising computer-executable instructions which, when the program is executed on a computer, perform a method according to any one of the steps according to any one of the embodiments disclosed above.

[0043] According to a further aspect of the invention, there is provided a computer device or other hardware device programmed to perform one or more steps of any one of the method embodiments disclosed above. According to another aspect, there is provided a data storage device encoding the program in machine-readable and machine-executable form for performing one or more steps of any one of the method embodiments disclosed above.

[0044] The accompanying drawings are used to illustrate presently preferred non-limiting exemplary embodiments of the devices of the invention. The above and other advantages and objects of the features of the invention will become more apparent and the invention will be better understood from the following detailed description when read in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0045]

Figure 1

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Figure 8

DETAILED DESCRIPTION OF THE INVENTION

[0046] FIG. 1 shows a first exemplary embodiment of a system for creating print data based on pixel data including a plurality of different ink or toner color values for each pixel. The system includes a color management module 10, a linearity compensation module 20, a merge module 30, an ink or toner restriction module 40, and a screening module 50.

[0047] The color management module 10 is configured to receive an image file and generate a plurality of page elements having, for each pixel of the image file, a plurality of ink or toner colors CMYK and an optional transparency bit T indicating whether the pixel is transparent. The color values CMYK output from the color management module 10 can be input in a form processed by the ink or toner restriction module 40 after being preprocessed first by the linearity compensation module 20 and the merge module 30. The color management module 10 may be any conventional color management module.

[0048] The linearity compensation module 20 is arranged upstream of the ink or toner limiting module 40, and for pixels having a plurality of different color values CMYK, a compensation coefficient function λ C λ M λ Y λ K is applied to obtain new color values C' = λ C .C, M' = λ M .M, Y' = λ Y .Y, K' = λ K .K', and is configured to output the new color values C'M'Y'K' for each page element to the merge module 30. The compensation coefficient functions λ C λ M λ Y λ K usually define compensation coefficients in a function of a single color value C, M, Y, K. Therefore, these compensation coefficients λ C λ M λ Y λ K are not constant coefficients but functions of color values. Each compensation coefficient function is preferably a continuous function of the color value.

[0049] In the illustrated embodiment, the linearity compensation module 20 is configured to apply compensation coefficients to the pixels of a plurality of page elements and determine new color values for each page element. The system further includes a merge module 30 configured to receive the new color values of each page element, merge the color values of each pixel of the page element to obtain a merged new color value C'M'Y'K' for each pixel, and input the merged new color value C'M'Y'K' to the ink or toner limiting module 40. The merge module 30 determines the new merged color value considering the transparency bit T. In other embodiments, the merging can be performed during or immediately after color profiling.

[0050] The ink or toner limiting module 40 is configured to apply at least one scaling coefficient function (λ CMYK or λ CMY or λ CM etc.) to at least one color combination to limit the amount of ink or toner applied during printing. Each scaling coefficient function for a certain color combination determines a scaled color value, e.g., (C’’ = λ CMYK .C’, M’’ = λ CMYK .M’, Y’’ = λ CMYK .Y’, K’’ = λ CMYK .K’) or (C’’ = λ CMY .M’, M’’ = λ CMY .M’, Y’’ = λ CMY .Y’, K’’ = K’) or (C’’ = λ CM .C’, M’’ = λ CM .M’, Y’’ = Y’, K’’ = K’) or a combination thereof, based on the color values associated with the specific color combination. When two color scaling coefficient functions are applied to a specific color, the minimum value of the two scaled color values can be used. See also the embodiment of FIG. 6 described below.

[0051] By applying the scaling coefficient function to a specific color combination, the limitation of the ink / toner amount can be carried out more precisely and quickly. For example, there are applications where only the YK color combination can be the target of the scaling coefficient function, and there are also applications where multiple color combinations (e.g., (YK and CM and CY) or (OYK and CMYK), etc.) can be the target of the scaling coefficient function.

[0052] Therefore, the ink or toner limiting module 40 functions in color combinations, and the linearity compensation module 20 performs scaling for individual colors. Placing the linearity compensation module 20 upstream of the ink or toner limiting module 40 as described above has the advantage that very precise limitations can be carried out for specific color combinations.

[0053] The screening module 50 is configured to receive the scaled color values from the ink or toner limiting module 40 and perform screening based on the optionally scaled color values. By screening, it is possible to determine whether a pixel needs to be printed. In screening, any suitable type of screening such as probabilistic or FM screening techniques, or cluster or AM screening techniques can be used.

[0054] FIG. 2 shows another exemplary embodiment in which the same or similar components are denoted by the same reference numerals. In the embodiment of FIG. 2, the merge by the merge module 30 is performed before the linearity compensation by the linearity compensation module 20. The color management module 10 is configured to generate a plurality of page elements having the color values of each pixel, and the merge module 30 is configured to receive the color values of each page element and merge the color values of each pixel of the plurality of page elements to obtain the merged color value CMYK of each pixel. Next, the linearity compensation module 20 is configured to apply a compensation coefficient to the merged color value to obtain a new color value C'M'Y'K' and input this new color value to the ink or toner limiting module 40. Such an embodiment may be possible when all page elements use the same linearity compensation.

[0055] FIG. 3 shows another exemplary embodiment in which the same or similar components are denoted by the same reference numerals. In the embodiment of FIG. 3, the merge by the merge module 30 is performed downstream of the ink or toner restriction module 40. The ink or toner restriction module 40 receives a plurality of page elements and is configured to apply at least one scaling coefficient function to at least one color combination for each page element to obtain scaled color values C''M''Y''K'' for each page element. The merge module 30 is configured to receive the scaled color values of each page element and merge the scaled color values of each pixel of the plurality of page elements to obtain a new merged color value for each pixel.

[0056] FIG. 4 shows another exemplary embodiment in which the same or similar components are denoted by the same reference numerals. In the embodiment of FIG. 4, the merge by the merge module 30 is performed prior to the color profiling by the color management module 10. The merge module 30 is configured to receive an image file having a plurality of page elements, merge the plurality of page elements to obtain a merged image file, and input the merged image file to the color management module 10.

[0057] FIG. 5 shows a first possible implementation of the ink or toner restriction module 40. The ink or toner restriction module 40 is configured to apply a single scaling coefficient function λ YK to the color combination YK. The scaling coefficient function for the color combination YK determines the scaled color values C'' = C', M'' = M', Y'' = λ YK .Y', K'' = λ YK .K'. In other words, only the color values of Y and K are scaled.

[0058] The ink or toner restriction module 40 preferably determines two input parameters f1 and f2 derived from the color values Y'K' for the color combination YK, and is configured to use the parameters f1 and f2 at the input to determine the value of the scaling coefficient function of the color combination. The input parameters f1 and f2 preferably include any one or a combination of the following: the sum of the color values of the color combination, the weighted sum of the color values of the color combination, the maximum color value of the color values of the color combination, the minimum color value of the color values of the color combination, the average of the color values of the color combination, the weighted average of the color values of the color combination, the median of the color values of the color combination. For example, f1 = Y' + K' and f2 = max(Y', K').

[0059] Figure 6 shows another possible implementation of the ink or toner restriction module 40. The ink or toner restriction module 40 is configured to apply three scaling coefficient functions λ CM , λ CY , λ YK to the color combinations CM, CY, and YK. Since the colors C and Y appear in two of the three color combinations, the minimum value of the scaled values of C and Y is taken. Thus, the scaled color values are C'' = min(λ CM .C', λ CY .C'), M'' = λ CM .M', Y'' = min(λ YK .Y', λ CY .Y'), K'' = λ YK .K'. In other words, all color values are scaled based on the scaling of the three color combinations of two colors.

[0060] The ink or toner restriction module 40 preferably determines, for each of the color combinations CM, CY, and YK, two input parameters f1, f2 derived from the color values C’M’, C’Y’, and Y’K’, and is configured to use the parameters f1, f2 at the input to determine the value of the scaling coefficient function of the color combination. The input parameters f1, f2 preferably include any one or a combination of the following: the sum of the color values of the color combination, the weighted sum of the color values of the color combination, the maximum color value of the color values of the color combination, the minimum color value of the color values of the color combination, the average of the color values of the color combination, the weighted average of the color values of the color combination, the median of the color values of the color combination.

[0061] FIG. 7 shows another possible implementation of the ink or toner restriction module 40. The ink or toner restriction module 40 is configured to apply scaling coefficient functions λ CMYK , λ CMY , λ CMK , λ CYK , λ MYK , λ YM , λ CM , λ CY , λ YK , λ CK , λ MK . Since the color CMYK appears in multiple color combinations, the minimum value of the scaled values of CMYK is taken. Thus, the scaled color value is C’’ = min(λ CMYK .C’, λ CMY .C’, λ CMK .C’, λ CYK .C’, λ CM .C’, λ CY .C’, λ CK .C’), etc. In other words, all color values are scaled based on the scaling of all color combinations of 2, 3, or 4 colors.

[0062] The ink or toner limitation module 40 is preferably configured to determine two input parameters f1 and f2 derived from the respective color values for all color combinations CMYK, CMY, CMK, CYK, MYK, CM, CY, CK, MY, MK, and YK, and to use the parameters f1 and f2 in the input to determine the value of the scaling coefficient function for that color combination. The input parameters f1 and f2 preferably include any one or a combination of the following: the sum of the color values of the color combination, the weighted sum of the color values of the color combination, the maximum color value of the color values of the color combination, the minimum color value of the color values of the color combination, the average of the color values of the color combination, the weighted average of the color values of the color combination, the median of the color values of the color combination.

[0063] Figure 8 shows a possible scaling coefficient function λ CMYK for scaling a combination of four color values, where f1 is the sum of the color values CMYK and f2 is the maximum value of the color values CMYK. Note that not all points on the graph are possible (for example, when the maximum value is 50, the sum cannot exceed 200, so a point with a maximum value of 50 and a sum exceeding 200 is not possible). As shown in the figure, the scaling coefficient function is preferably a continuous function of the color values associated with each color combination. In the example shown in the figure, when C + M + Y + K exceeds approximately 300, the scaling coefficient λ CMYK becomes extremely low.

[0064] A person skilled in the art will readily recognize that the steps of the various methods described above can be performed by a programmed computer. In this specification, some embodiments are also intended to cover a program storage device, for example, a digital data storage medium that is machine or computer readable and encodes a program of machine-executable or computer-executable instructions, the instructions performing some or all of the steps of the above methods. The program storage device can be, for example, a digital storage device, a magnetic storage medium such as a magnetic disk or magnetic tape, a hard drive, or an optically readable digital data storage medium. Embodiments are also intended to cover a computer programmed to perform the above steps of the method.

[0065] The functions of the various elements shown in the figures, including any functional blocks labeled "module", can be provided using dedicated hardware and hardware capable of executing software in conjunction with appropriate software. When provided by a processor, the functions can be provided by a single dedicated processor, a single shared processor, or multiple individual processors (some of which may be shared). Furthermore, the explicit use of the term "module" should not be construed as exclusively referring to hardware capable of executing software, but may implicitly include digital signal processor (DSP) hardware, network processors, application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), read only memory (ROM) for storing software, random access memory (RAM), and non-volatile storage, but is not limited thereto. Other hardware (conventional and / or custom) may also be included.

[0066] Although the principles of the present invention have been described above in connection with specific embodiments, it should be understood that this description is by way of example only and not as a limitation of the scope of protection determined by the appended claims.

Claims

1. A system for creating print data based on pixel data that includes multiple different ink or toner color values ​​(C'M'Y'K') for each pixel, To limit the amount of ink or toner applied during printing, at least two scaling factor functions (λ) are applied to at least two color combinations. ＣＭＹＫ , λ ＣＭＹ , λ ＣＭ , λ ＹＫ The system includes an ink or toner limiting module (40) configured to apply such an application, Each scaling coefficient function of the color combination determines the scaled color value (C''M''Y''K'', C''M''Y'', C''M'', Y''K'', etc.) based on the color value among a plurality of color values ​​(C'M'Y'K', C'M'Y', C'M', Y'K', etc.) associated with the color combination. The aforementioned at least two color combinations include at least two different combinations of two colors (CM, YK, CY, etc.). A system characterized by the following features.

2. The system further comprises a linearity compensation module (20) located upstream of the ink or toner limiting module, The linearity compensation module (20) For pixels having multiple different color values ​​(CMYK), a compensation coefficient function (λ) is applied to one or more individual color values ​​among the multiple color values. Ｃ , λ Ｍ , λ Ｙ , λ Ｋ Apply ) and Obtain new color values ​​(C'M'Y'K'), The aforementioned new color values ​​(C'M'Y'K') The aforementioned ink or toner limiting module (40), or An intermediate module between the linearity compensation module (20) and the ink or toner limiting module (40) is provided. It is configured to output, The system according to claim 1.

3. The ink or toner limiting module (40) The scaled values of the colors (λ ＣＭＹＫ C’, λ ＣＭＹＫ M’, λ ＣＭＹＫ Y’, λ ＣＭＹＫ K’, λ ＣＭＹ C’, λ ＣＭＹ M’, λ ＣＭＹ Y’, λ ＣＭ C’, λ ＣＭ M’, etc.) that appear in the at least two color combinations and two or more combinations, apply the at least two scaling coefficient functions to determine, The scaled color values ​​(C'', M'', Y'', K'',) are determined using a function. The system according to claim 1, configured as described above.

4. The ink or toner limiting module (40) For one of the two aforementioned color combinations, at least one input parameter (f1, f2) is determined, derived from the color value of the color combination. The scaling coefficient function of the color combination uses the at least one input parameter. The system according to claim 1, configured as described above.

5. The aforementioned at least one input parameter is The sum of the color values ​​of the color combination, the weighted sum of the color values ​​of the color combination, the maximum color value of the color combination, the minimum color value of the color combination, the average of the color values ​​of the color combination, the weighted average of the color values ​​of the color combination, the median of the color values ​​of the color combination, Including any one of the following or a combination thereof, The system according to claim 4.

6. A color management module (10) is configured to receive an image file and generate a plurality of ink or toner color values ​​for each pixel of the image file, which are input to the ink or toner limiting module (40) either directly or in a processed format. The system according to claim 1, further comprising:

7. A screening module (50) configured to receive the scaled color values ​​and optionally perform screening based on the scaled color values, The system according to claim 1, further comprising:

8. The linearity compensation module (20) applies the compensation coefficient function (λ) to the pixels of multiple page elements. Ｃ , λ Ｍ , λ Ｙ , λ Ｋ It is configured to apply this and determine the new color value for each page element, The aforementioned system, A merge module configured to receive the new color values ​​of each page element, merge the color values ​​of each pixel of the plurality of page elements to obtain a merged new color value (C'M'Y'K') for each pixel, and input the merged new color value (C'M'Y'K') to the ink or toner limiting module (40), The system according to claim 2, further comprising:

9. The color management module (10) is configured to generate a plurality of page elements, each having a color value for a pixel. The aforementioned system, A merge module configured to receive the color values ​​of each page element, merge the color values ​​of each pixel of the multiple page elements, and obtain the merged color value (CMYK) of each pixel. The system according to claim 6, further comprising:

10. The ink or toner limiting module (40) receives multiple page elements and, for each page element, obtains the scaled color value of each page element (C''M''Y''K'', C''M''Y'', C''M'', etc.) by applying at least one scaling factor function (λ) to at least one color combination. ＣＭＹＫ , λ ＣＭＹ , λ ＣＭ It is configured to apply (etc.), The aforementioned system, A merge module configured to receive the scaled color values ​​of each page element, merge the scaled color values ​​of each pixel of the plurality of page elements, and obtain a new merged color value for each pixel. The system according to claim 1, further comprising:

11. A merge module configured to receive an image file having multiple page elements, merge the multiple page elements to obtain a merged image file, and input the merged image file into the color management module (10), The system according to claim 6, further comprising:

12. A method for configuring the system described in any one of claims 1 to 11, Optionally, at least one associated pre-set scaling factor (λ ＣＭＹＫ０ , λ ＣＭＹ０ , λ ＣＭ０ The steps include printing a first test patch with different color values ​​for each of the at least two color combinations using (etc.), Based on the printed first test patch, the at least two scaling factor functions (λ) of the at least two color combinations are determined. ＣＭＹＫ , λ ＣＭＹ , λ ＣＭ The scaling value (λ) used in (etc.) ＣＭＹＫ１ , λ ＣＭＹ１ , λ ＣＭ１ The steps include determining (etc.) Includes, The above method is optional, A printing step comprising printing a plurality of second test patches with different color values ​​for each individual color, wherein the amount of ink or toner applied during printing is limited using at least two scaling coefficient functions (λCMYK, λCMY, λCM, etc.) having the determined values, Based on the second test patch described above, the steps include determining the compensation coefficient function (λ C, λ M, λ Y, λ K) for each individual color, Methods that further include the above.

13. A method for creating print data based on pixel data that includes multiple different ink or toner color values ​​(C'M'Y'K') for each pixel, Based on the aforementioned color values ​​(C'M'Y'K'), at least two scaling coefficient functions (λ) are applied to at least two color combinations. ＣＭＹＫ , λ ＣＭＹ , λ ＣＭ A step of applying (etc.) to determine a scaled color value (C''M''Y''K'', C''M''Y'', C''M'', etc.) based on the color value among the plurality of color values ​​(C'M'Y'K', C'M'Y', C'M', etc.) related to the color combination, and limiting the amount of ink or toner applied during printing. Includes, The at least two color combinations include at least two different combinations of two colors (such as YK, CY, CM, etc.), and optionally, the at least two color combinations include only combinations of two colors. method.

14. The aforementioned method, Before applying the two scaling coefficient functions mentioned above, for pixels having multiple different color values ​​(CMYK), a compensation coefficient function (λ) is applied to each of the multiple color values. Ｃ , λ Ｍ , λ Ｙ , λ Ｋ Apply the following to obtain new color values ​​(C'M'Y'K'): the at least two scaling coefficient functions (λ ＣＭＹＫ , λ ＣＭＹ , λ ＣＭ The step of applying the new color values ​​(C'M'Y'K') in the step of applying the above (etc.), For one of the at least two color combinations, the steps include: deriving at least one input parameter (f1, f2) from the color value of the color combination, and using the at least one input parameter as input to the at least two scaling coefficient functions; A step of receiving an image file and generating a plurality of ink or toner color values ​​to be used in a form that is optionally further processed in the step of applying the at least two scaling factor functions to each pixel of the image file, This includes one or more of the following: The aforementioned at least one input parameter is optional, The sum of the color values ​​of the aforementioned color combination, the weighted sum of the color values ​​of the aforementioned color combination, the maximum color value of the aforementioned color combination, the minimum color value of the aforementioned color combination, the average of the color values ​​of the aforementioned color combination, the median of the color values ​​of the aforementioned color combination, Including any one of the following or a combination thereof, The method according to claim 13.

15. A computer program product that includes computer executable instructions, The computer program product wherein the computer executable instruction performs the method according to claim 13 when the program is executed on a computer.

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