Approach on digital radiographs enhancement based on wavelet transform

Digital radiographs play very important role in medical imaging. However, the image quality has weakness with lower contrast and some noises owing to various reasons. So it is necessary to enhance these images to facilitate the postprocessing or diagnosis. In this paper, our method utilized wavelet transform to decompose the image, removed the noise using wavelet threshold method, and modified the high coefficients using nonlinear method and the low coefficient using the unsharp masking method. At last, the enhanced image got through inverse wavelet transform. At the same time, we also analyzed the characteristics of several common wavelet bases. Experiments were carried out on a digital radiograph with some different wavelet bases and some other traditional approaches. The results showed that this method had better enhancing effect than traditional approaches.