Super-Resolution Based on Curvelet Transform and Sparse Representation

Super-resolution techniques are used to reconstruct an image with a high resolution from one or more low-resolution image(s). In this paper, we pro-posed a single image super-resolution algorithm. It uses the nonlocal mean filter as a prior step to produce a denoised image. The proposed algorithm is based on curvelet transform. It converts the denoised image into low and high frequencies (sub-bands). Then we applied a multi-dimensional interpolation called Lancozos interpolation over both sub-bands. In parallel, we applied sparse representation with over complete dictionary for the denoised image. The proposed algorithm then combines the dictionary learning in the sparse representation and the inter-polated sub-bands using inverse curvelet transform to have an image with a higher resolution. The experimental results of the proposed super-resolution algorithm show superior performance and obviously better-recovering images with enhanced edges. The comparison study shows that the proposed super-resolution algorithm outperforms the state-of-the-art. The mean absolute error is 0.021 & PLUSMN; 0.008 and the structural similarity index measure is 0.89 & PLUSMN; 0.08.