Image resolution enhancement using multi-wavelet and cycle-spinning

Abstract

In this paper a multi-wavelet and cycle-spinning based image resolution enhancement technique is presented. The proposed technique generates a high-resolution image for the input low-resolution image using the input image and an inverse multi-wavelet transform (all multi-wavelet high frequency subbands' coefficients are set to zero). The concept of the cycle spinning algorithm in conjunction with the multi-wavelet transform is then used to generate a high quality super-resolution image for the input image from the resulting high resolution image, as follows: A number of replicated images with different spatial shifts from the resulting high-resolution image is first generated; Each of the replicated images is de-correlated into its subbands using a multi-wavelet transform; The multi-wavelet high frequency subbands' coefficients of each of the de-correlated images are set to zero and then a primary super-resolution image for each of these images is produced using an inverse multi-wavelet transform; The resulting primary super-resolution images are then spatially shift compensated and the output super-resolution image is created by averaging the resulting shift compensated images. Experimental results were generated using four standard test images and compared to the state of art techniques. Results show that the proposed technique significantly outperforms the classical and non-classical super-resolution methods both subjectively and objectively.