Analysis iteration fast frequency spectrum extrapolation method for single image restoration

The invention discloses an analysis iteration fast frequency spectrum extrapolation method for single image restoration, comprising an iteration system initialization process and an analysis iteration process, wherein in the iteration system initialization process, a degraded image frequency spectrum is calculated, and a primary iteration solution and a system primary parameter are set; in the analysis iteration process, the level of images and gradient information along a vertical direction are estimated by continuously elaborate gradient information threshold values in a shrinking way, a forecasting frequency spectrum is forecasted and obtained by analyzing an iteration frequency spectrum and gradient information frequency spectrum, and a high-definition image is obtained by synthetically correcting the degraded image frequency spectrum and forecasting frequency spectrum analysis through image frequency spectrum synthesis correction. The analysis iteration fast frequency spectrum extrapolation method is based on a fast Fourier transform technique, achieves the fast image restoration with little complexity through frequency spectra below cut-off frequencies and by extrapolating frequency spectra above the cut-off frequencies and has obviously superior deblurring and noise restraining capability compared with a conventional method, thereby obviously enhancing the signal-to-noise ratio; and the analysis iteration fast frequency spectrum extrapolation method is convenient to realize by utilizing image processing hardware formed by fast Fourier transform DSP chips.