Digital radiography(DR) image enhancement based on weighted red-black wavelets transform
Yin Zhao · Journal of Jinan University · 2015
Aim: An enhancement algorithm based on weighted red-black wavelets( WRB) transform is presented to solve the problems of details buried and wide dynamic range in original DR images. Methods: logarithmic transformation was first performed on the original DR images. then,the changed images were decomposed within the WRB architecture to get the wavelet coefficients of each layer. Furthermore a piecewise nonlinear coefficient operation function was designed to process the coefficients. In the end,the enhanced images were reconstructed by the inverse WRB transform. Results: The proposed algorithm is tested on the original DR images and compared with some other enhancement algorithms. The average running time of our algorithm is about 0. 6 seconds and significantly faster than the other algorithms. Using our enhancement algorithm,both of the details and local contrast of the DR images are promoted,meanwhile no halo artifacts have been produced in the enhanced images. Furthermore,the information entropy and cross entropy indices of our algorithm are better than that of the other algorithms. Conclu-sion: The proposed enhancement algorithm is an effective and efficient method for compressing image dynamic range,enhancing image details of the original DR images.