“Color to gray and back” using DST-DCT, haar-DCT, walsh-DCT, hartley-DCT, slant-DCT, kekre-DCT hybrid wavelet transforms

Abstract

The paper shows performance comparison of DST-DCT, Haar-DCT, Walsh-DCT, Hartley-DCT, Slant-DCT and Kekre-DCT Hybrid Wavelet Transforms using Normalization for ‘Color to Gray and Back’. The color information of the image is embedded into its gray scale version using hybrid wavelet transform [HWT] and normalization method. Instead of using the original color image for storage and transmission, gray image (Gray scale version with embedded color information) can be used, resulting into better bandwidth or storage utilization. Among the three algorithms considered the second algorithm give better performance as compared to first and third algorithm. In our experimental results second algorithm for Haar-DCT HWT and Walsh-DCT HWT using Normalization gives better performance in ‘Color to gray and Back’ w.r.t all other transforms in method 1, method 2 and method 3. The intent is to achieve compression of 1/3 and to store and send color images as gray image and to be able to recover the color information afterwards.