Model-based adaptive enhancement of far infrared image sequences

Two enhancement algorithms, the spatial and spatiotemporal homomorphic filt ering (SHF and STHF), were proposed in (Highnam, R., Brady, M., 1997. IEEE Trans. Pattern Anal. Machine Intell. 19, 410-415) to enhance far infrared i mages based upon a far infrared imaging model. In this paper, we theoretica lly and experimentally prove that the enhanced results with SHF are in gene ral smoother than those with STHF, although STHF may reduce the processing time greatly in comparison to SHF. Based on this conclusion, an adaptive sp atiotemporal homomorphic filtering (ASTHF) algorithm is proposed. The adapt ive factor of ASTHF is also discussed in detail to obtain the trade off bet ween smoothness and convergence time. (C) 2000 Elsevier Science B.V. All ri ghts reserved.