Patent ID: 8416337

Claim:
An image process apparatus for processing a color image signal, comprising: an integration unit integrating at least one of each of color signals of the color image signal or a brightness signal obtained from the color image signal over at least one horizontal period; a normalization unit normalizing an integration value obtained by the integration unit and a difference between the integration values of adjacent fields or frames obtained by the integration unit; a frequency analysis unit extracting spectrum of output values of the normalization unit; a flicker component estimating unit estimating a flicker component from the spectrum extracted by the frequency analysis unit; an index generating unit calculating an index representing a probability that a photographing light source is a fluorescent lamp, and a difference between a theoretical difference value and an actual difference value between initial phase components of adjacent fields or frames from the flicker component estimating unit; and a color balance control unit configured to: calculate a color balance control value of the color image signal according to the index from the index generating unit and a weighted coefficient interpolated between a plurality of control target points for a fluorescent lamp area and a plurality of control target points to determine a final control target point, wherein the weighted coefficient is based on the probability that the light source is a fluorescent lamp; the fluorescent lamp area is an area in which the probability that the light source is a fluorescent lamp is high; and the fluorescent lamp area is previously stored in the color balance control unit; determine whether the color image signal is in the fluorescent lamp area; and update held value of white balance control gains based on the calculated color balance control value, in response to determining that the color image signal is in the fluorescent lamp area.