Restoration of Defocus Blur Image Based on Global Phase Coherence

In this paper, a novel approach of defocus blur image restoration is proposed, which is based on Global Phase Coherence (GPC). As a good sharpness indicator, GPC was testified to be effective for restoration of defocus blur image. Since a deconvolution kernel was designed based on Wiener filter, the additive noise was able to be estimated in several flat regions, which are selected by Normalized Total Variation (NTV) measurement. Moreover, according to the unimodal property between GPC of images obtained via deconvolution and estimated defocus blur radius, a "Pyramid" search is adopted to determine the exact blur radius and restore the image. The experimental results reveal that the proposed method was particularly effective for defocus blur image even with additive noises.