Single Image Refocusing and Defocusing: A post processing method for single-image refocusing and defocusing using focus-map estimation and blind de-convolution framework

Abstract

A post processing method to tackle the single-image refocusing-and-defocusing problem. The proposed method can accomplish the tasks of focus-map estimation and image refocusing and defocusing. Given an image with a mixture of focused and defocused objects, we first detect the edges of objects within in image and then estimate the focus map based on the edge blurriness. In focus map image we find the difference in foreground and background objects present within that image. Thresholding is process to extract the objects from the background by selecting the threshold value T that separates the two modes. That is if pixel value is less than the threshold value T then we replace the pixel value by black and if pixel value is less than the threshold value T then we replace the pixel value by white. The image refocusing problem is addressed in a blind de-convolution framework and image defocusing problem is addressed by using filters.