An efficient approach for colour image enhancement using Discrete Shearlet Transform

Image enhancement is a key processing on an image for wide range of applications. Contrast enhancements improve the perceptibility of an image by changing the pixels intensity of the input image. In this study, a novel method for image contrast enhancement is proposed based on Discrete Shearlet Transform (DST) for color images. In order to obtain high contrast enhancement image, the RGB image is first converted into HSV (Hue, Saturation and Value) color space. The converted hue color channel is only taken into the account for DST decomposition. After that higher sub bands of hue component are eradicated and lower sub bands are only considered for reconstruction. Finally, high contrast image is obtained by using reconstructed Hue for HSV colour space and convert this colour space into RGB color space. The performance of the proposed contrast image enhancement method is compared with existing histogram equalization based image enhancement. The visualization based results show that the proposed contrast image enhancement system achieves satisfactory performance.