Colour image enhancement based on wavelet approximation coefficient histogram

In this paper, a new method for color image enhancement based on wavelet transform is presented. The three different colour channels such as R, G, and B of the input color image are separated initially. The proposed technique decomposes the different colour channels into the four frequency sub-bands by using Discrete Wavelet Transform (DWT). Histogram Equalization is applied to the low frequency sub-band only. Finally, the inverse wavelet transform is applied to reconstruct the enhanced image. Mean is the parameter which is used to measure the performance of the proposed method.