Tonality correcting circuit and hue correcting circuit

A hue correcting circuit comprising:

• hue detecting means for detecting a hue component for each pixel from a first color difference signal R-Y and a second color difference signal B-Y;
• first offset providing means for providing an offset for each pixel to the first color difference signal R-Y depending on the detected hue component for each pixel;
• and
• second offset providing means for providing an offset for each pixel to the second color difference signal B-Y, thereby correcting a hue only for an arbitrary hue.

A color correcting circuit characterized in that within a color difference signal plane, the range of a hue is divided into a plurality of regions by at least two division axes passing through the origin, and by comprising:

• judging means for judging, on the basis of input color difference signals R-Y and B-Y, to which of the regions the hue of the input color difference signal belongs, and
• color difference signal converting means for subjecting the input color difference signal whose hue is judged to belong to the predetermined region to color difference signal conversion processing,
• the color difference signal converting means comprising
• coefficient calculating means for calculating, in a case where it is assumed that a position vector of the input color difference signal whose hue is judged to belong to the predetermined region is decomposed into vector components corresponding to the two adjacent division axes, the coefficient of each of the vector components, and
• means for respectively primarily converting said vectors corresponding to the two division axes by a transform matrix previously set, to convert the input color difference signal on the basis of the vectors corresponding to said two axes after the primary conversion and the coefficients calculated by the coefficient calculation means.

A color correcting circuit characterized in that within a color difference signal plane, the range of a hue is divided into a plurality of regions by at least two division axes passing through the origin, and by comprising:

• judging means for judging, on the basis of input color difference signals R-Y and B-Y, to which of the regions the hue of the input color difference signal belongs, and
• color difference signal converting means for subjecting the input color difference signal whose hue is judged to belong to the predetermined region to color difference signal conversion processing,
• the color difference signal converting means comprising
• coefficient calculating means for calculating, in a case where it is assumed that a position vector of the input color difference signal whose hue is judged to belong to the predetermined region is decomposed into vector components corresponding to the two adjacent division axes, the coefficient of each of the vector components, and
• means for converting the input color difference signal on the basis of vectors corresponding to said two axes after the conversion, which have been previously set for said vector components corresponding to the two division axes and the coefficients calculated by the coefficient calculating means.