IMAGE PROCESSING APPARATUS AND IMAGE FORMING APPARATUS

摘要

An image processing apparatus converts first color values in a first color space to second color values in a second color space for an objective color. If the objective color is not within a color reproduction space of an outputting device, the searching unit searches for a set of color values as base color values in the color reproduction space so that the set of color values minimizes a value of the color difference formula for the first color values. As the second color values, the searching unit determines a set of color values in a predetermine neighbor space of the base color values so that the determined set of color values minimizes a difference between property values on a color property of which the allowed color difference is smallest among the allowed color differences at the first color values.

主权项

1. An image processing apparatus converting first color values in a first color space to second color values in a second color space for an objective color, comprising:
a color converting unit configured to calculate the second color values on the basis of the first color values using a color difference formula that evaluates a color difference between two sets of color values in a coordinate system of plural color properties that at least include brightness; and a storage device configured to store allowed color difference data that indicates respective predetermined allowed color differences corresponding to property values of the plural color properties; wherein the second color space is a color space of a predetermined outputting device; and the color converting unit comprises:
an inside-outside identifying unit configured to identify whether the objective color is a color within a color reproduction space of the outputting device or not, anda searching unit configured to find the second color values corresponding to the first color values of the objective color using the color difference formula;wherein the searching unit is further configured (a) to search for a set of color values in the second color space so that the set of color values minimizes a value of the color difference formula for the first color values and determine the set of color values as the second color values, if the objective color is a color within the color reproduction space of the outputting device; and to (b1) search for a set of color values as base color values in the color reproduction space so that the set of color values minimizes a value of the color difference formula for the first color values and (b2) as the second color values, determine a set of color values in a predetermine neighbor space of the base color values in the second color space so that the determined set of color values minimizes a difference between property values on a color property of which the allowed color difference is smallest among the allowed color differences at the first color values, if the objective color is not a color within the color reproduction space of the outputting device.