Patent ID: 7391450

Claim:
For a digital image signal obtained from a photo-sensor having a two-dimensional array of individual pixels with an optical field incident thereon wherein the image signal of the optical field is altered according to an additional intensity distribution pattern across the array, a sequence of outputs of the individual pixels resulting from said pixels being linearly scanned across the optical field forming the photo-sensor digital signal, a method of modifying the image signal to correct for the intensity distribution pattern, comprising: maintaining modification data of the intensity distribution pattern as a function of radial distances of the pixels from an optical center of the intensity distribution pattern defined to include at least one elliptical or hyperbolic intensity pattern across the sensor, including storing points along a single radius across the intensity distribution pattern from the optical center thereof and values of slopes between said points, wherein the values of said stored points have been calculated from measurements through the optical sensor by the device optical system viewing an image field having a uniform intensity thereacross, characterizing intensity variations of the image signal output of the sensor by defining one or more sets of ellipses or hyperbolas, finding a single optical center of the intensity variation pattern and then calculating values of a set of points along the single radius as the modification data, calculating the radial distances of the individual pixels being scanned from their linear position within the two-dimensional array, generating modifications for the individual pixels being scanned from the image modification data being accessed by the calculated radial distances thereof, and combining the generated image modification data with the outputs of the corresponding individual pixels being scanned, thereby modifying the sequence of outputs of the individual pixels according to the image modification data.