Images employing focal plane array detectors suffer from aliasing and fixed pattern noise generated by nonuniformities in the response of the detector elements. Aliasing which is caused by undersampling may be removed by microscan which extends the spatial bandwidth of the images by a factor of two. The presence of fixed pattern noise which is caused by nonuniformities in the detector responses is more difficult to eliminate. It severely reduces the performance of imagery and its removal is essential. This paper compares the performance of representative methods for reducing the effect of fixed pattern noise through simulated results. Preliminary results are presented for an alternative method currently under development.