Image Blur Map Estimation Based on the Difference between Surrounding Block of Pixel and Its Blurred Version

Blur is one of the common image distortions in which fraction of a pixel value, depending on the severity of blur, is added to one or moreneighboring pixels. Knowledge about the severity of blurrinessin a given image is very importantfor image enhancementpurposes. Sinceblur severity is not generally constant at all pixels, it is necessary to accurately estimate the blurriness value of pixels in the image (the so called blur map). In this paper, a methodis proposed for this purpose.The proposed method in this paper provides the blur map via estimating the blurriness of the pixels based on the difference between surrounding block of the pixel and its blurred version. Our investigations indicate that, in general, the blur image regions have lower frequency content than the un-blur (sharp) regions. The results of extensive experiments on a large database including motion and defocus blurred images confirmthe superiority of the proposed approachover the existing methods.