Optimal Reference Frame Search Algorithm for Better Restoration of Image Sequences Distorted by Turbulence of the Medium

This paper presents a novel approach in image restoration based on calculating the pixel shift-maps of geometrically distorted images in a video sequence and using these maps to obtain non-distorted frames by de-warping the originals. In the similar previous approaches, the reference frame in the image registration process for pixel shift-maps calculation is selected either using a blind image quality metric or simply using the first frame. However, the former technique may not estimate the best frame accurately in the sense of geometric distortion. As for the latter, there is always a possibility that the first frame is one of the most distorted ones in the sequence. In the proposed method, an optimal reference frame search algorithm is introduced to improve the quality of restored frames and to yield a stable video output. The proposed method was applied both to synthetic and real data sets, and simulation results show significant improvement in comparison to the state-of- the-art methods.