An efficient brightness preserving contrast enhancement technique using discrete wavelet transform and singular value decomposition

Abstract

The primary necessities of vision based application are to have an image with good contrast and brightness of the image. In image enhancement, we process given image; therefore, results are more appropriate than given image for any particular application or set of objectives. A new technique is for enhancement of given image having low contrast based on brightness preserving dynamic histogram equalization, singular value decomposition and discrete wavelet transform are suggested. There are four sub-bands of different frequencies: high-high, high-low, low-high and low-low are obtained by the DWT decomposition of the given image. For improving image’s contrast, BPDHE technique is applied on the specific image and to boost the illumination, this contrast enhanced image’s LL band information and input image’s LL band information are passed through SVD. Through inverse discrete wavelet transform, output image obtained having high contrast. Quantitative metric and qualitative result of presented technique are evaluated and compared with other existing techniques. A result reveals that presented technique is more effective strategy for enhancement of image having low contrast. The technique presented by this study is simulated on Intel I3 64-bit processor using MATLAB R2013b.