Generating column offset corrections for image sensors

摘要

An image sensor includes multiple photoactive pixels and multiple dark reference pixels typically arranged in rows and columns to form a pixel array. A dark signal is read out from a given number of dark reference pixels in each column at a first gain level. An initial column offset correction is determined for one or more columns in the pixel array using respective dark signals read out at the first gain level. The initial column offset corrections are repeatedly scaled in response to each detected change to a different gain level. The column offset corrections can be scaled based on an amount of change between each respective different gain level and the first gain level.