totalsum now represents the sum of the intensity values for all shielded pixels in the current sub region plus the totalsum for any previous sub regions minus the intensity values of any damaged pixels that might be present in the form of dark dead pixels or bright hot pixels in block 412 sregion is compared to s the number of sub regions if sregion is greater than s which would indicate the last of the sub regions had been processed then the operation continues with block 414 otherwise the operation continues on with block 408 and by adding one to sregion where the average of the shielded pixels is subtracted from a predetermined reference reference is the desired constant signal value in the shielded region of the sensor in block 416 the calculated offset is added to each active pixel in the current row in block 418 row is compared to the number of rows on the sensor if row is greater than the number of rows on the sensor to be filtered then all the rows of the sensor have been processed and the operation terminates otherwise the operation adds one to row and continues on with block 406 foregoing described embodiments of the invention are provided as illustrations and descriptions they are not intended to limit the invention to precise form described in particular it is contemplated that functional implementation of invention described herein may be implemented equivalently in hardware software firmware and or other available functional components or building blocks and that networks may be wired wireless or a combination of wired.