  Considering the problem of color distortion caused by the defogging algorithm
based on dark channel prior, an improved algorithm was proposed to calculate
the transmittance of all channels respectively. First, incident light
frequency's effect on the transmittance of various color channels was analyzed
according to the Beer-Lambert's Law, from which a proportion among various
channel transmittances was derived; afterwards, images were preprocessed by
down-sampling to refine transmittance, and then the original size was restored
to enhance the operational efficiency of the algorithm; finally, the
transmittance of all color channels was acquired in accordance with the
proportion, and then the corresponding transmittance was used for image
restoration in each channel. The experimental results show that compared with
the existing algorithm, this improved image defogging algorithm could make
image colors more natural, solve the problem of slightly higher color
saturation caused by the existing algorithm, and shorten the operation time by
four to nine times.
