I. Introduction
Reproducing the visual richness of a real-world scene is an essential goal of digital photography. The real images, however, are often blurred during image acquisition due to the effect of many factors such as camera shake, object motion, and out-of-focus [1]. The resulting blurry images will not only degrade the perceptual quality of photos but also degenerate the performance of many image analytic and understanding models [2]. Blind image deblurring, which has been studied extensively in low level vision for decades [3], plays an essential role in improving the visual quality of real-world blurry images.