Abstract: Low-contrast and heavy noise are main shortages of X-ray medical images, which makes the images vague and uncertainly. As result,some very useful details characteristic are weakened which are difficult to distinguish even by naked eyes. Based on the analysis of multi-resolution wavelet transform and bilateral filtering operator,a kind of image enhancement algorithm for detail characters was presented. hhe algorithm can enhance the detail characters while confining noise amplifying and keeping lower distortion. The analysis of the results shows that local regions of the image are enhanced by using the 8-neighbor grad contrast of the wavelet transform coefficient, which makes the detail characters of image clearer adaptively. Experiments were conducted on real pictures, and the results show that the algorithm is flexible and convenient.

Key words: X-ray image, Enhancement, Wavelet transform, Bilateral filtering