Abstract: Common image enhancements based on human visual property compress the dynamic range of images while enhancing the contrast,so that the whole contrast is not high and the effects on edges are not satisfactory.By analyzing the global and local adaptation of the human visual system and the transfer property of retinal ganglion cells,an algorithm for biomimetic image enhancement is proposed in this paper.Firstly a global logarithm transformation is carried out on the whole image to adapt the sense property of the human visual system;secondly the tri-Gaussian model is adopted to adjust the local contrast based on the local linear relationship between subjective brightness(intensity as perceived by the human visual system)and the logarithm of the light intensity incident on the eye;finally,a linear transformation is used to convert the enhanced image back to a color image.The experimental results show that our proposed algorithm has better performance compared to other methods.In particular,in terms of image border treatment,the proposed algorithm can not only enhance the border contrast,but also efficiently recover the area luminance contrast and luminance gradient information.