Wavelet domain based directional dictionaries for single image super-resolution
Junaid Ahmed, Bin Gao, Gui Yun Tian · 2017
This paper introduces wavelet domain-based multiple dictionary learning for single image super-resolution. A coupled dictionary learning mechanism is employed using sparsity with the desirable properties of the wavelet transform, such as directionality, analysis at many resolution levels, and persistence across scales. This approach ensures that coupling between signal features (at two consecutive levels) becomes more prominent. We design six pairs of coupled, low and high resolution wavelet sub-band dictionaries. The dictionaries are compact and directional. Super-resolution is achieved by using these low and high resolution dictionaries. Compared to state of the art algorithms, results show significant improvements for the reconstruction of low-resolution images.