Edge preserving super-resolution algorithm using multi-stage cascaded joint bilateral filter

Abstract

Super-resolution (SR) algorithms address the inabilities of poor imaging devices, there by producing high quality images with enhanced resolution. We propose a new SR approach which produces sharp high resolution (HR) image using its low resolution (LR) counterparts. The proposed method uses geometric duality for spatially adapting covariance-based interpolation (CBI). To preserve edge information, a multi-stage cascaded joint bilateral filter (MSCJBF) is proposed as an intermediary stage. These edges are incorporated in the high frequency subbands obtained by the stationary wavelet transform (SWT), through nearest neighbor interpolation (NNI) method. Prior to the NNI process, the high frequency subbands undergo two-lobed lanczos interpolation to achieve the desired resolution enhancement. The quantitative and qualitative analysis for various test images prove the superiority of our method.