Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Iterative Desensitisation of Image Restoration Filters under Wrong PSF and Noise Estimates | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2007 Article ID 72658 18 pages doi 2007 72658 Research Article Iterative Desensitisation of Image Restoration Filters under Wrong PSF and Noise Estimates Miguel A. Santiago 1 Guillermo Cisneros 1 and Emiliano Bernues2 1 Departamento de Senales Sistemas y Radiocomunicaciones Escuela Tecnica Superior de Ingenieros de Telecomunicacion Universidad Politécnica de Madrid 28040 Madrid Spain 2 Departamento de Ingenieria Electronica y Comunicaciones Centro Politecnico Superior Universidad de Zaragoza 50018 Zaragoza Spain Received 19 July 2005 Revised 30 November 2006 Accepted 3 January 2007 Recommended by Bernard C. Levy The restoration achieved on the basis of a Wiener scheme is an optimum since the restoration filter is the outcome of a minimisation process. Moreover the Wiener restoration approach requires the estimation of some parameters related to the original image and the noise as well as knowledge about the PSF function. However in a real restoration problem we may not possess accurate values of these parameters making results relatively far from the desired optimum. Indeed a desensitisation process is required to decrease this dependency on the parameter errors of the restoration filter. In this paper we present an iterative method to reduce the sensitivity of a general restoration scheme but specified to the Wiener filter with regards to wrong estimates of the said parameters. Within the Fourier transform domain a sensitivity analysis is tackled in depth with the purpose of defining a number of iterations for each frequency element which leads to the aimed desensitisation regardless of the errors on estimates. Experimental computations using meaningful values of parameters are addressed. The proposed technique effectively achieves better results than those obtained when using the same wrong estimates in the Wiener approach as well as verified on an SAR restoration. .
