Power-log based plateau limit histogram equalization algorithm for infrared image enhancement

Abstract

In this paper, we propose a power logarithm based plateau limit histogram equalization algorithm to enhance infrared images. Conventional histogram equalization methods lag significantly while enhancing infrared images whose histogram contains large spikes. To diminish the effects of large spikes log transformation is used which additionally aids in the expansion of the smaller values in the histogram. Power transformation assists in regaining the original shape of the histogram while clipping of histogram in a plateau limit is beneficial to reduce the over enhancement of the image. Plateau limit is set to the mean of modified histogram after the power-log transformation. After that, the modified histogram is equalized independently to achieve the enhanced output. Experimental results demonstrate that the proposed power-log based plateau limit histogram equalization algorithm efficiently enhances the contrast of infrared images while, quantitative measures and visual quality assessment effectively validate the superiority of the proposed algorithm with respect to the other traditional histogram equalization algorithms.