Physical quantity interpolating method, and color signal processing circuit and camera system using the same

A color image signal processing circuit for generating an output image comprising:

• a region/representative-point determination unit operable to select, from among representative points of color signals set in advance, at least first and second representative points sandwiching an input color signal, the first and second representative points serving as reference points;
• a correction amount calculator operable to compute a correction amount for the input color signal using area ratios for triangles having their respective vertices located at a point of origin, the first representative point and a point corresponding to a value of the input color signal;
• the point of origin, the second representative point and the point corresponding to a value of the input color signal and a further triangle having its vertices located at the first and second representative points and the point corresponding to a value of the input color signal;
• and
• a saturation/hue correction unit operable to perform an arithmetic correction operation derived by the correction amount calculator and an uncorrected color signal and to output an operation result, and further wherein a ratio of vector products determines a value of the third vector, and further wherein the first and second vectors are predetermined reference vectors.

A camera system for extracting a color signal from an image signal output from an imager having an arrangement of a plurality of light-receiving elements, correcting color of the color signal using a color signal processing circuit, and outputting the color-corrected color signal,

• wherein the color signal processing circuit includes
• a region/representative-point determination unit operable to select, from among representative points of color signals set in advance, at least first and second representative points sandwiching an input color signal, the first and second representative points serving as reference points;
• a correction amount calculator operable to compute a correction amount for the input color signal using area ratios for triangles having their respective vertices located at a point of origin, the first representative point and a point corresponding to a value of the input color signal;
• the point of origin, the second representative point and the point corresponding to a value of the input color signal and a further triangle having its vertices located at the first and second representative points and the point corresponding to a value of the input color signal;
• and
• a saturation/hue correction unit operable to perform an arithmetic correction operation derived by the correction amount calculator and the uncorrected color signal and to output an operation result, and further wherein a ratio of vector products determines a third vector, and further wherein the first and second vectors are predetermined reference vectors.