1. A method for processing color pixel data of an image, comprising the steps of: computing with hardware using bit-shift operations an approximation of at least one of a plurality of other color space components of a pixel represented in RGB color space, wherein the at least one other color space component includes luminance, and an approximation of luminance (Y) is computed by summing a red component (R) of the pixel shifted a first number of bits, a green component (G) of the pixel shifted a second number of bits, and a blue component (B) of the pixel shifted a third number of bits; and evaluating a characteristic of the pixel in response to the computed approximation of the at least one of the plurality of other color space components, wherein the first number of bits is two, the second number of bits is one and the third number of bits is two; wherein the step of evaluating a characteristic of the pixel comprises comparing at least one of the computed other color space components of the pixels to a predetermined threshold value; and wherein computing at least one of a plurality of other color space components of a pixel represented in RGB color space further comprises the steps of: computing an approximation of chrominance component Cr of the pixel by computing ((R>>1)+(R>>2)−(R>>5))−((Y>>1)+(Y>>2)−(Y>>5)), wherein “X>>n” represents shifting RGB color space component X by n bits to the right; and computing an approximation of chrominance component Cb of the pixel by computing ((B>>1)+(B>>4))−((Y>>1)+(Y>>4)).