Color signal processing circuit, image capture device and method for processing color singal

Abstract

The color signal processing circuit includes a first calculation unit generating an R / G value, a second calculation unit generating a B / G value, and a position specifying unit specifying, based on the R / G and B / G values, a position expressed as a color temperature of the light of a light source in a color coordinate system defined by R / G and B / G coordinate axes as the position of the light source. The color signal processing circuit further includes a pull determining unit determining a displacement amount between the light source position specified and a position of a target point on a blackbody radiation curve defined in the color coordinate system, sets gain values for the R, G, B color signals for achieving a white balance based on the displacement amount, and supplies the gain values to white balance amps amplifying the R, G, B color signals, and carries out white balance processing.

Description

technical field [0001] The present invention relates to a color signal (color signal) processing circuit, an image pickup (imagepickup) device and a color signal method, which can be advantageously applied to adjust red (R), green (G) and blue (B) primary color signals ( The white balance is adjusted by gains of R, G, B color signals (hereinafter referred to as R, G, B color signals) generated by an image pickup element irradiated with light incident from a light source via an optical system. Background technique [0002] In the past, digital still cameras, digital video cameras, and the like have been provided as examples of image pickup devices that automatically perform white balance processing. Here, the term "white balance processing" refers to processing that, when taking an image of a white object illuminated by a given light source, changes the respective gains of the R, G, B color signals obtained from the camera system such that The signals all become equal. [0...

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Problems solved by technology

[0004] However, it is difficult to use a formula to accurately and uniformly express the blackbody radiation curve (expressing the color temperature change as a curve)

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