A new single-image fog removal algorithm based on physical model

摘要

Based on the physical model of atmospheric scattering and the optical reflectance imaging model, three major factors which affect the effect of fog removal are discussed in detail, dark channel phenomenon is explained via the optical model, and an approach for solving the parameter in the atmospheric scattering model is rigorously derived from a new perspective. Using gray-scale opening operation and fast joint bilateral filtering techniques, the proposed algorithm can effectively obtain the global atmospheric light and greatly improve the speed and accuracy of atmospheric scattering function solving. Finally, the scene albedo is recovered by inverting this model. Compared with existing algorithms, complexity of the proposed method is only a linear function of the number of input image pixels and this allows a very fast implementation. The simulation results show that the processing time of images with a resolution of 576*768 is only 1.7 s; Results on a variety of outdoor foggy images demonstrate that the proposed method achieves good restoration for contrast and color fidelity, resulting in a great improvement in image visibility.