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Variational Dirichlet Blur Kernel Estimation

A Matlab program that implements the variational Dirichlet blur kernel estimation method in X. Zhou, J. Mateos, F. Zhou, R. Molina, and A.K. Katsaggelos, “Variational Dirichlet Blur Kernel Estimation”, IEEE Transactions on Image Processing, vol. 24, no. 12, 5127-5139, December 2015. doi: 10.1109/TIP.2015.2478407


Blind image deconvolution involves two key objectives, latent image and blur estimation. For latent image estimation, we propose a fast deconvolution algorithm, which uses an image prior of nondimensional Gaussianity measure to enforce sparsity and an undetermined boundary condition methodology to reduce boundary artifacts. For blur estimation, a linear inverse problem with normalization and nonnegative constraints must be solved. However, the normalization constraint is ignored in many blind image deblurring methods, mainly because it makes the problem less tractable. In this paper, we show that the normalization constraint can be very naturally incorporated into the estimation process by using a Dirichlet distribution to approximate the posterior distribution of the blur. Making use of variational Dirichlet approximation, we provide a blur posterior approximation that takes into account the uncertainty of the estimate and removes noise in the estimated kernel. Experiments with synthetic and real data demonstrate that the proposed method is very competitive to state-of-the-art blind image restoration methods.


Motion blur

Input Xu et al. [1] Ours


Atmospheric blur

Input Babacan et al. [2] Xu et al. [1] Ours



  • Manuscript: X. Zhou, J. Mateos, F. Zhou, R. Molina, and A.K. Katsaggelos, “Variational Dirichlet Blur Kernel Estimation”, IEEE Transactions on Image Processing, vol. 24, no. 12, 5127-5139, December 2015. doi:10.1109/TIP.2015.2478407 [pdf] (2.86M)
  • MATLAB Code and data: [zip] (17.9M)
  • Numerical results of Algorithm 1: [zip] (5.2M)


[1] L. Xu, et al., “Unnatural l0 sparse representation for natural image deblurring,” in CVPR, 2013.

[2] S. Babacan, et al., “Bayesian blind deconvolution with general sparse image priors,” in ECCV, 2012.


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Visual Image Processing
University of Granada