Blind image resolution enhancement based on a 2D constant modulus algorithm

Abstract

In almost all super-resolution methods, the blur operator is assumed to be known. However, in practical situations this operator is not available or available only to a finite extent. In this paper, a super-resolution algorithm is presented in which the assumption of availability of the blur parameters is not necessary. It is a two-dimensional and single-input multiple-output extension of the well-known constant modulus algorithm which is widely used for blind equalization in communication systems. The algorithm consists of determining a set of deconvolution filters to be applied on re-sized low-resolution and low-quality images and is suitable for pure translational motion only. An important property of the method is that the blur operators do not have to be the same for the observed low-resolution images, and also they do not need to be shift-invariant. Experimental results show that the proposed method can satisfactorily reconstruct the high-resolution image and remove the blur especially for five or less-bit images.