In this paper, we introduce robust and synergetic hand-crafted features and a simple but efficient deep feature from a convolutional neural network (CNN) architecture for defocus estimation. This paper systematically analyzes the effectiveness of different features, and shows how each feature can compensate for the weaknesses of other features when they are concatenated. For a full defocus map estimation, we extract image patches on strong edges sparsely, after which we use them for deep and hand-crafted feature extraction. In order to reduce the degree of patch-scale dependency, we also propose a multi-scale patch extraction strategy. A sparse defocus map is generated using a neural network classifier followed by a probability-joint bilateral filter. The final defocus map is obtained from the sparse defocus map with guidance from an edge-preserving filtered input image. Experimental results show that our algorithm is superior to state-of-the-art algorithms in terms of defocus estimation. Our work can be used for applications such as segmentation, blur magnification, all-in-focus image generation, and 3-D estimation.
In this paper, we address the problem of estimating and removing non-uniform motion blur from a single blurry image. We propose a deep learning approach to predicting the probabilistic distribution of motion blur at the patch level using a convolutional neural network (CNN). We further extend the candidate set of motion kernels predicted by the CNN using carefully designed image rotations. A Markov random field model is then used to infer a dense non-uniform motion blur field enforcing motion smoothness. Finally, motion blur is removed by a non-uniform deblurring model using patch-level image prior. Experimental evaluations show that our approach can effectively estimate and remove complex non-uniform motion blur that is not handled well by previous approaches.  This paper proposes a novel statistical approach to formulate image sharpness metric using eigenvalues. Statistical information of image content is represented effectively using a set of eigenvalues which is computed using singular value decomposition (SVD). The approach is started by normalizing the test image with its energy to minimize the effects of image contrast. Covariance matrix which is computed from the normalized image is then diagonalized using SVD to obtain its eigenvalues. Sharpness score of the test image is determined by taking the trace of the first six largest eigenvalues. The performance of the proposed approach is gauged by comparing it with orthogonal moments-based sharpness metrics. Experimental results show the advantages of the proposed approach in terms of providing wider working range and more precise prediction consistency in noisy condition.