The blur direction and blur length are two key parameters to recover motion-blurred images. In view of the defects that low precision and the limitation of angle range in the method of detecting center bright stripe of Fourier spectra image. Based on the analysis of the mathematical principle of Radon transformation and the causes of cross-shaped bright line and its interference, according to the characteristics of spectral images,the improved approach of using the dark line of Fourier spectra image to iden...