An image fusion framework using novel dictionary based sparse representation

Image fusion is an important technique which aims to produce a synthetic result by leveraging the cross information available in the existing data. Sparse Representation (SR) is a powerful signal processing theory used in wide variety of applications like image denoising, compression and fusion. Construction of a proper dictionary with reduced computational efficiency is a major challenge in these applications. Owing to the above criterion, we propose a supervised dictionary learning approach for the fusion algorithm. Initially, gradient information is obtained for each patch of the training data set. Then, the edge strength and information content are measured for the gradient patches. A selection rule is finally employed to select the patches with better focus features for training the over complete dictionary. By the above process, the number of input patches for dictionary training is reduced to a greater extent. At the fusion step, the globally learned dictionary is used to represent the given set of source image patches. Experimental results with various source image pairs demonstrate that the proposed fusion framework gives better visual quality and competes with the existing methodologies quantitatively.