Learning Based Single Image Blur Detection and Segmentation

This paper addresses the problem of obtaining a blur-based segmentation map from a single image affected by motion or defocus blur. Since traditional hand-designed priors have fundamental limitations, we utilise deep neural networks to learn features related to blur and enable a pixel-level blur classification. Our approach mitigates the ambiguities present in blur detection task by introducing joint learning of global context and local features into the framework. Specifically, we train two sub-networks to perform the task at global (image) and local (patch) levels. We aggregate the pixel-level probabilities estimated by two networks and feed them to a MRF based framework which returns a refined and dense segmentation-map of the image with respect to blur. We also demonstrate via both qualitative and quantitative evaluation, that our approach performs favorably against state-of-the-art blur detection or segmentation works, and show its utility to applications of automatic image matting and blur magnification.