Patent ID: 7688487

Claim:
A scanner, comprising: a plurality of sampling-amplified-offset devices configured to sample, amplify, and compensate levels of an R charge signal, a G charge signal, and a B charge signal, respectively, to obtain an R analog signal, a G analog signal, and a B analog signal according to the sampling, amplifying, and compensating; a gain adder configured to multiply the R, G, and B analog signals by corresponding weighted values and to add the R, G, and B weighted analog signals to obtain a summed analog signal; and a multiplexer configured to select at least one of the R analog signal, the G analog signal, the B analog signal, or the summed analog signal as an output signal; wherein at least one of the sampling-amplified-offset devices includes: a sampler configured to obtain a plurality of samples on at least one of the R, G, or B charge signals and to determine a luminance based, at least in part, on a difference between at least two of the samples; a programmable gain amplifier configured to obtain an amplified luminance according to a gain value; and an offset device configured to compensate the R, G, or B analog signal of the at least one of the R, G, and B charge signals, respectively, based, at least in part, on the obtained amplified luminance.