Patent ID: 7009639
Filing Date: 2006-03-07
Classification: H04N

Abstract:
1. A color imaging apparatus comprising: a solid-state image sensor having photosensors color-coded with three primary color filters formed like a matrix correspondingly to pixels of the solid-state image sensor, to provide three primary color signals acquired as captured image signals; a four-channel signal detecting means for detecting, from the three primary color signals provided from the solid-state image sensor, an R signal acquired from R pixels in a horizontal line of R, G, R, G, . . . , R and G color filters, a Gr signal acquired from the G pixels in the same horizontal line, a Gb signal acquired from G pixels in a horizontal line of G, B, G, B, . . . , G and B color filters, and a B signal acquired from the B pixels in the same horizontal line; a four-channel variable-gain amplifying means whose channels are controllable in gain independently of one another to amplify the R, Gr, Gb and B signals, wherein said R, Gr, Gb and B signals are amplified to substantially the same levels as one another, and wherein both luminance and chrominance signals are generated using the amplified four signals; and a gain controlling means for controlling, based on an output from the signal detecting means, the gains of R and B channels of the variable-gain amplifying means so that the R and B signals amplified by the variable-gain amplifying means are equal in level for an achromatic color image, and said gain controlling means generating a mean value of the outputs of Gr and Gb channels of the variable-gain amplifying means so that the amplitude difference between the luminance signal for the horizontal line of R, G, R, G, . . . , R and G color filters produced from the R and Gr signal and the luminance signal for the horizontal line of G, B, G, B, . . . , G and B color filters produced from the B and Gb signal is substantially reduced.