Patent ID: 8310716
Filing Date: 2012-11-13
Classification: H04N

Abstract:
1. A method for designing a black generation transfer curve, the method comprising: producing a table to convert a first signal in a first signal space to a second signal in a second signal space; during each of a plurality of iterations for a device, generating a black generation transfer curve for the device; obtaining at each successive iteration color measurement data of the device, wherein the color measurement data relates to a signal-to-color response of the device, and wherein the signal-to-color response is based on measured color of output of the device; using the color measurement data to obtain a perceptual constraint between the first signal and the second signal, wherein the perceptual constraint is a linearity constraint based on linearizing a fractional arclength along a device gamut boundary with respect to a dark point and a chromatic primary or secondary color point, the device gamut boundary being obtained from color measurement data of the device; designing at each successive iteration a black generation transfer curve for the device constrained by two bounding curves that depend on the color measurement data of the device; and adjusting either a black generation transfer curve related to a “K” component or a black generation transfer curve related to a chromatic component of a cyan, magenta, yellow, and black (CMYK) signal, wherein the black generation transfer curve that is not adjusted is automatically updated in relation to the adjustment based on the perceptual constraint, wherein a black generation transfer curve related to a single chromatic primary component of a CMYK signal is adjustable, and a black generation transfer curve related to the remaining two chromatic primary components of the CMYK signal is fixed.