Patent ID: 8090214

Claim:
A method of detecting halo artifacts in an image, programmed in a memory of a device, the method comprising: a. determining a first two-dimensional gradient field for an image, wherein the first gradient field includes a plurality of first gradient vectors, one first gradient vector associated with each pixel in the image; b. determining a second two-dimensional gradient field for a processed image of the image, wherein the second gradient field includes a plurality of second gradient vectors, one second gradient vector associated with each pixel in the processed image, wherein a first pixel in the image corresponds to a first pixel in the processed image; c. calculating a gradient angle for each pixel, wherein a first gradient angle is an angle between a first gradient vector associated with the first pixel in the image and a second gradient vector associated with the first pixel in the processed image; d. calculating a relative angle for each pixel, wherein a first relative angle for the first pixel in the processed image is the minimum between the first gradient angle and 360 degrees minus the first gradient angle; e. identifying a halo artifact, wherein the relative angle equals the halo artifact at each pixel.