Blind Estimation of Blur Parameters by 2D-DFT on Polar Coordinate System Presented on Rectangular Grids

Abstract

We propose a blind identification method to estimate blur parameters of a noisy image. The noisy image is blurred and degraded due to linear motion and defocusing. In a polar coordinate system, 2D-Fourier transform of a degraded image is derived. The blur parameters are blindly estimated from the magnitude of the spectrum in the polar system, and represented on a rectangular grid. In this grid representation, vertical and horizontal projections are calculated to estimate the length and the orientation of uniform linear motion blur. As for defocus blur, only horizontal projection is used to get a blurring radius. Experimental results show that the method is accurate and computationally efficient. The estimated results are close to true values, even when the image is heavily contaminated by additive salt and pepper noise.