Retinex Model in Discrete Cosine Transform Domain for Image Enhancement
Zhang Xinlong, Yong Shen, Xuan Zhang, Ronggui Wang · Journal of Engineering Graphics · 2011
Existing image enhancement algorithms by using of Discrete Cosine Transform mostly treat the DCT coefficients uniformly,and can not inhibit artifacts.By introducing Retinex idea into DCT,a new enhancement algorithm is proposed.The algorithm divides DCT coefficients into illumination component and reflection component.The dynamic range of illumination component is mapped to an ideal range,using a function with strong light bating.The local details of reflection component are enhanced by defining a band limited contrast measure.The block artifacts will be suppressed using a block decomposing method.Compared to MSR and DCT enhancement algorithms,results verify this approach’s efficiency of details enhancement and strong light bating,also with artifacts suppressed.