Patent ID: 7920212

Claim:
A digital gamma correction circuit for performing gamma correction on input image data by defining a gamma correction broken line approximating an ideal gamma correction curve, the circuit comprising: a data setting portion for setting set values for defining the gamma correction broken line, the set values representing a broken baseline including one or more break points and (N−1) approximate line segments provided for each break point and having their respective slopes obtained by dividing a difference in slope between two line segments adjacent at the break point included in the broken baseline into N, N being an integer of 2 or more; a coefficient calculation portion for calculating coefficients for primary expressions representing the approximate line segments based on the set values set by the data setting portion; (N−1) arithmetic portions for calculating (N−1) output candidate values as candidates for an output value that is obtained by subjecting the input image data to the gamma correction, based on, among the coefficients calculated by the coefficient calculation portion, coefficients for (N−1) primary expressions representing (N−1) approximate line segments at a break point corresponding to a value of the input image data; and a result selection portion for selecting an output candidate value corresponding to the gamma correction broken line from among the (N−1) output candidate values calculated by the arithmetic portions, and setting the selected output candidate value as the output value that is obtained by subjecting the input image data to the gamma correction.