Trade-offs between Color Saturation and Noise Sensitivity in Image Sensors

A color correction matrix is usually used to transf o r m the raw color image obtained f r o m color image sensors to adjust f o r factors such as variations in illumination and deviations of the actual filter characteristics f rom the ideal. Color correction matrices that have high condition numbers can greatly amplify noise, while it can be dificult to achieve good color saturation with low condition number matrices. Noise can be a significant problem f o r digital camera images which have limited bit-depth. W e explore the trade-off between noise reduction and color saturation analytically, and using digital camera images. W e present a n orthonormality criterion t o define optimality with respect to noise sensitivity and color saturation in the case of signal-independent, orthogonal sensor measurement noise in each color channel.