Patent ID: 7583863

Claim:
A receiving module, comprising: a patterned filter layer comprising regions of filter material that transmit a portion of light received at the patterned filter layer and filter-free regions that transmit all of the light received at the patterned filter layer, the regions of the filter material and the filter-free regions being regions arranged in rows and columns such that at least one of the filter-free regions is positioned between the regions of the filter material in each row and in each column; a light-detecting sensor positioned to receive the light transmitted through the patterned filter layer, the light-detecting sensor including an arrangement of pixels, some of the pixels of the light-detecting sensor being positioned to receive the light transmitted through the regions of filter material of the patterned filter layer, some of the pixels of the light-detecting sensor being positioned to receive the light transmitted through the filter-free regions of the patterned filter layer and a controller configured to determine at least one gain factor for images detected by the light-detecting sensor using a pixel-based contrast defined as C p =|(feature signal in frame N -feature signal in frame M )/|(scene signal in frame N -scene signal in frame M ) Where C p is the pixel-based contrast and N and M are integer numbers, wherein the scene signal represent a background scene of the images and the feature signal represents at least one feature of interest in the images.