The invention discloses a
single image defogging method based on block-by-block nonlinear brightness prior, which belongs to the technical field of
image processing, and comprises the following steps of: dividing a
fog-containing image into local blocks, calculating the average brightness of the blocks, and constructing prior block-by-block monotone increasing nonlinear mapping to represent the corresponding relationship between the brightness of
fog-containing blocks and the brightness of clear blocks; an atmospheric scattering model is combined, an atmospheric light vector is modeled into a vector, the vector and a PPWF form a parameterized
recovery model, three scalar parameters are taken as a core, an optimal parameter is obtained through multi-target joint optimization, alternate optimization and golden section search, and finally a defogged image is generated. The method has the advantages of few parameters,
low complexity and no need of training data, the definition and global contrast of far and near scenery can be remarkably improved while the
image structure is maintained, and halo, excessive enhancement and color cast are effectively inhibited; the method has good robustness for different
fog densities and illumination conditions, and is suitable for real-time and embedded defogging application of single-channel or multi-channel images.