Polyphase FIR Wiener filtering for image resolution enhancement
Boaz Cohen and Its’hak Dinstein
Electrical and Computer Engineering Department,
Ben-Gurion University of the Negev,
P.O. Box 653, Beer-Sheva 84105, Israel.
Abstract-
A method for reconstruction and restoration of super resolution images from sequences of noisy low-resolution images is presented. After estimating the projective transformation parameters between a selected reference image and the observed degraded image sequence frames, the data is rearranged into a sequence with only quantized sub pixel translations. Next, the imaging system's point spread function (PSF) and the auto-correlation function of the image are estimated with a resolution higher than that of the super resolution image. The coefficients of the FIR Wiener filter are computed, low-pass filtered, and decimated so a polyphase filter bank is obtained. Each one of the images in the translated rearranged sequence is filtered by its corresponding polyphase filter. These filtering results are summed and locally normalized according to the apparent data. The super resolution result is refined by estimating the values of pixels that could not be reconstructed by interpolation. The use of the polyphase filters allows exploitation of the input data without any averaging operations needed when implementing conventional FIR Wiener filtering. The presented experimental results show good resolution improvement in presence of noise.