The invention discloses an image defogging method based on an improved dynamic atmospheric
scattering coefficient function, and the method comprises the steps: solving a minimum channel image throughemploying R, G and B color channels of an original image, and calculating an atmospheric light value A of a foggy day image through a
quadtree segmentation method; calculating the
depth of field d (x)of the image by using a nonlinear color attenuation prior model, and filtering
noise information in the
depth of field d (x) of the image through minimum filtering, smooth filtering and guided filtering to obtain the final
depth of field dr (x) of the image; and finally, in combination with the improved dynamic atmospheric
scattering coefficient function beta (x) and the image depth of field dr (x) obtained through final
processing, calculating atmospheric transmissivity t (x), and recovering a
fog-free image through an atmospheric scattering model. The method not only can solve the problem of inaccurate transmissivity
estimation caused by constant atmospheric
scattering coefficient, but also can effectively solve the phenomenon of color
distortion of the
sky area of the image, so that the defogging effect of the image is clearer and more thorough, and the color of the scenery is more natural and real.