Image Superresolution Based on Interpolation of Complex Daubechies Wavelet Coefficients

In this study, a new single frame technique for superresolution (SR) based on (symmetric) Daubechies Complex Wavelet Transform (DCWT) is proposed. DCWT is known for numerous advantages including linear phase, directionality and nearly invariant to shift, rotation and scale. The high frequency real component coefficients and all the imaginary component coefficients of the DCWT are bicubic interpolated with an arbitrary factor while the low frequency real component coefficient is substituted with the input image which is bicubic interpolated with half of the interpolation factor. Synthesis is then done with inverse DCWT resulting into a SR output. Standard test images are used in this work for easy comparison. Visual and tabular results confirm the superiority of the proposed technique over conventional and state-of-the-art single frame SR methods.