SUPER RESOLUTION FOR EGYPTSAT-1 IMAGES WITH ERRATIC SHIFT
A. H. Nasr, Gh.S. El-Tawel and A. K. Helmy
DOI : 10.3844/jcssp.2014.1324.1335
Journal of Computer Science
Volume 10, Issue 7
The key point of the Super-Resolution (SR) process is the accurate registration of the low resolution images, i.e., accurate measuring of the fixed shift between them, to obtain high resolution image. Due to certain malfunction, some Egyptsat-1 images have inconsistent sub-pixel shift. Therefore, in this study we propose a methodology to use this kind of shift for reconstructing a SR image of Egyptsat-1 from its low resolution bands. It is a trade-off between the capability of catching spatial details and the sensitivity to the erratic shift existed along the image. Firstly, this inconsistent shift between the bands is transformed into reliable shift. Then a SR method based on image fusion scheme with multi-resolution decomposition is performed. The fusion process is conducted in steerable wavelet domain using normalized convolution technique. It allows the recognition of objects with size approaching its limiting spatial resolution. Results show that the proposed methods make significant spatial resolution improvements from 7.8 to 4 m. Different quantitative measures of the proposed methodology were assessed and tested with some implemented commonly used SR methods. These methods are; nonparametric bayesian, POCS, iterative-interpolation, robust and iterated back projection. The visual and quantitative evaluations verify the usefulness and effectiveness of the proposed methodology.
© 2014 A. H. Nasr, Gh.S. El-Tawel and A. K. Helmy. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.