A comparison of wavelet based techniques for resolution enhancement of Moderate Resolution satellite images

Satellite image resolution enhancement is an active area of research. There are many techniques which perform well in the Standard image domain but tend to give inconsistent and unacceptable results in the case of satellite images. Thus there is a need to modify the existing techniques and develop new ones to overcome this short coming. This paper presents several image resolution enhancement techniques like WZP (Wavelet Zero Padding), WZP-CS (Wavelet Zero padding and Cycle Spinning), DWT (Discrete Wavelet Transform) and DWT-SWT with Error back projection that were adapted to the satellite images by modifications to the original technique. These techniques were applied on MODIS (Moderate Resolution Imaging Spectroradiometer) images and the results have been evaluated using standard quality assessment parameters like PSNR, RMSE and Correlation Coefficient. The initial moderate resolution and the final high resolution images obtained through the different techniques are also illustrated in the paper. The outcome of this evaluation indicates that the techniques which achieved very good PSNR values in Standard images do not necessarily reiterate the same in case of satellite images. The results also reinforce that the modified techniques fare well to preserve the information content of the satellite images and improve the quality.