Patent ID: 7280705

Claim:
A digital imaging system, comprising: an image sensor comprising a two-dimensional array of pixel elements, said image sensor outputting digital signals as pixel data representing an image of a scene; a frame buffer, in communication with said image sensor, coupled to store said pixel data provided by said image sensor; and a tone correction circuit coupled to receive pixel data from said frame buffer and compute tone corrected pixel data using one or more tone correction curves, wherein said tone correction circuit computes tone corrected pixel data for a first pixel by generating a pixel mask for an m×n neighborhood of pixels surrounding said first pixel, the pixel mask classifying the m×n neighborhood of pixels to a first value and a second value according to one or more threshold values, applying a blending mask of weight factors to said pixel mask and computing a selector value based on said pixel mask and weight factors associated with said blending mask, said selector value being used to derive a first tone correction curve for use to compute said tone corrected pixel data for said first pixel; and wherein the selector value is computed by counting the number of first values in the pixel mask corresponding to a respective weight factor in the blending mask, multiplying each count value by the respective weight factor, and summing the count-weight factor products to obtain the selector value.