Patent ID: 8854690
Filing Date: 2014-10-07
Classification: G06F,G06K,H04N

Abstract:
1. A creation method of a total color material amount restriction table that defines a conversion relationship to convert an input CMYK signal prior to total color material amount restriction to an output CMYK signal subjected to total color material amount restriction, in order to restrict a total color material amount provided to a recording medium in an image formation apparatus that forms an image on the recording medium using color materials of cyanogen (C), magenta (M), yellow (Y) and black (K), the method comprising: a step of acquiring a first converter that calculates a value of a color material amount represented by a second scale with a physical meaning indicating an amount of a color material provided to the recording medium by the image formation apparatus, from a signal value from the signal value represented by a first scale that defines a used amount of each of the color materials of C, M, Y, and K; a step of acquiring a second converter that calculates a signal value represented by the first scale from the value of the color material represented by the second scale; a step of setting a total color material amount upper limit value represented by the second scale; and a table creation processing step of creating the total color material amount restriction table that defines an output CMYK signal with a total color material amount equal to or less than the total color material amount upper limit value with respect to an input CMYK signal, using the first converter, the second converter and the total color material amount upper limit value, wherein: the table creation processing step includes: a first processing step of deciding an output CMYK signal corresponding to an input CMYK signal when each of signal values of C, M, and Y in the input CMYK signal is a maximum value in a domain of the signal value defined by the first scale; a second processing step of deciding a K value of an output CMYK signal corresponding to an input CMYK signal using one or two kinds of color materials among C, M, and Y; a third processing step of deciding a CMY value of an output CMYK signal corresponding to an input CMYK signal using one kind of color material among C, M, and Y; a fourth processing step of deciding a CMY value of an output CMYK signal corresponding to an input CMYK signal using two kinds of color materials among C, M, and Y; a fifth processing step of deciding a CMYK value of an output CMYK signal corresponding to an input CMYK signal using three kinds of color materials among C, M, and Y; and the fifth processing step includes processing that defines an output CMYK signal with a total color material amount equal to or less than the total color material amount upper limit value, using a total color material amount value calculated by first interpolation processing that performs a first interpolation calculation in a space of a total color material amount by the second scale and a CMYK value calculated by second interpolation processing that performs a second interpolation calculation in a space of the first scale.