Techniques for improving the quality of images are described. A first histogram of intensity values may be obtained for an input image and diffused to obtain a second histogram with better intensity coverage. The diffusion may be achieved by filtering the first histogram for multiple iterations with a diffusion function obtained based on a filter function and a diffusion control function. The filter function may control the rate and/or characteristics of the diffusion. The diffusion control function may control shifts in positions of lobes in the first histogram. A transformation function may be determined based on a first cumulative distribution function (CDF) for the first histogram and an inverse function for a second CDF for the second histogram. An output image may be generated by mapping each pixel value in the input image to a corresponding pixel value in the output image based on the transformation function.