Patent ID: 7446812

Claim:
A method of operating an image sensor comprising an array of pixel cells, the method comprising: arranging the pixel cells in rows and subgroups, each subgroup including two adjacent rows of pixel cells, arranging the pixel cells into first and second subsets such that the first subset includes every other subgroup beginning with an uppermost row, the second subset includes every other subgroup beginning with a third row, such that the first and second subsets do not include same subgroups; accumulating first charge in a first subset of pixel cells during a first integration period; accumulating second charge in a second subset of pixel cells during a second integration period, a length of the first integration period being different than a length of the second integration period, the pixel cells accumulating only first or second charge per frame; reading out the accumulated first and second charge; and further comprising the act of producing respective synthetic signals corresponding to each pixel cell of the array using results of the readout accumulated first and second charge, wherein producing respective synthetic signals comprises applying the equation R(i,j)=S(i,j)+S(i,j+2) to produce synthetic signals corresponding to respective pixel cells of the first subset and applying the equation R(i,j)=S(i,j)+S(i,j−2) to produce synthetic signals corresponding to respective pixel cells of the second subset, where i is a column number of a pixel cell, j is a row number of the pixel cell, S is an original signal for a pixel cell, and R is the synthesized signal corresponding to a pixel cell.