Fixed pattern noise reduction

A method, including receiving signals, from a rectangular array of sensor elements arranged in rows and columns, corresponding to an image captured by the array. The method also includes analyzing the signals along a row or a column to identify one or more local turning points, and processing the signals at the identified local turning points to recognize fixed pattern noise in the captured image. The method further includes correcting values of the signals from the sensor elements at the identified local turning points so as to reduce the fixed pattern noise in the image.