A method of processing one or more detected signal images each acquired from a field of view of a chemical array reader. A location correction is determined based on different detected signals at different image regions which represent regions in the field of view having the same actual signal. Alternatively or additionally, a location correction is applied to a detected signal at an image region. The location correction reduces detected signal discrepancy between different regions in an acquired image which represent different regions in the field of view having the same actual signal. An array reading system and computer program products are also provided.