The Research For Non-uniformity Correction Of Infrared Focal Plane Arrays

IRFPA (Infrared Focal Plane Arrays), which is a newly developed detectingdeviceinthesefewdecades,has advantages ofhighsensitivity,highSNR andcompactstructure. It is one of the highest potential IR imaging devices. With the improvedperformance, it is widely applied in both fields of military and civil. But confined bythe techniques and materials, the IRFPA has character of non-uniformity in eachsensingunit,whichresultsintheFPN(FixedPatternNoise)andhasabadeffectontheimage.Therefore,itis necessarytocorrectthenon-uniformity.Firstly, we have a simple introduction to the development situation of the IRimaging technology and the purpose of this paper. Then we discuss the structure andtheory of the IRFPA. The definition of non-uniformity and response model are given.Then we evaluate several popular non-uniformity algorithms. And the merits anddefects ofeachalgorithmarepresented.Secondlywe have a fully analyzing of the THP (Temporal High Pass) algorithm.A 1-D signal simulation is given to illustrate how the"ghosting-artifacts"form.According to the character of the"ghosting-artifacts", this problem can be solved byinputtingtheedge-blurredimagetothefilter.Lastly, a sub-pixel registration using integral projection is proposed. It separatestarget image into several blocks and applies edge-detection technique on each block.Select theblock withmost edges intarget image andcorrespond blockinthereferenceimage to register. Apply projection on the blocks and shift the projected vector onepixel each time in a limited range, and then calculate the fractional translation withinterpolation and MSE value for each shift, the point of the minimum MSE should bethemotionvector.