Patent ID: 8045029

Claim:
A complementary metal-oxide semiconductor (CMOS) image sensor, comprising: a pixel array including red (R) pixels, green (G) pixels, blue (B) pixels, an effective pixel array, and a dummy pixel array configured to be shielded from light; a first analog signal processing path and configured to process analog signals output from the G pixels of the pixel array, wherein the first analog signal processing path is subdivided into a G sub-path and a G′ sub-path; and a second analog signal processing path configured to process analog signals output from both the B pixels and the R pixels of the pixel array, wherein the second analog signal processing path is subdivided into a BR sub-path and a B′R′ sub-path; wherein each of the first and second analog signal processing paths includes: a plurality of correlated double-sampling/programmable gain amplifiers (CDS/PGAs) configured to process output signals of pixels corresponding to same colors on different paths; a digital signal processor (DSP) configured to generate a digital average offset value for each path using signals of the dummy pixel array; a unit configured to convert each digital average offset value into at least one analog average offset value; and a signal synthesizing unit configured to synthesize the analog average offset value and signals of the effective pixel array, configured to output a synthesized signal; wherein a first portion of the G pixel signals are processed on the G sub-path, a second portion of the G pixels are processed on the G′ sub-path, a first portion of the R pixels and a first portion of the B pixels are processed on the BR sub-path, and a second portion of the R pixels and a second portion of the B pixels are processed on the B′R′ sub-path.