This paper proposes to make super-resolution for low-resolution image via a hybrid scheme making use of the wavelet domain processing and the New Edge-Directed Interpolation (NEDI). The proposed method combines the accurate low frequency information obtained from the wavelet transform and phase-free high frequency information predicted from the Shift-Free NEDI (SF-NEDI). The underlying idea of this approach is to study the pixel shift caused by the wavelet transform and to fix this problem when using the SF-NEDI to enlarge image, such that more accurate high frequency information can be extracted from the enlarged image. By using the framework of wavelet transform, the proposed approach uses the original low-resolution image and high frequency information from the SF-NEDI to realize image super-resolution. Extensive experimental results show that the proposed hybrid approach can achieve about 0.7 dB improvement in peak signal-to-noise ratio over the Wavelet Zero-padding and 1.35 dB over the SF-NEDI.
['Zhi-Song Liu', 'Wan-Chi Siu', 'Jun-Jie Huang']
Image super-resolution via hybrid NEDI and wavelet-based scheme