A X-ray image sharpening algorithm using nonlinear module

Abstract

The unwanted information such as noises and interferences usually affects the quality of X-ray image. Therefore, information extraction must be performed. The unsharp masking method is a well-known approach for image enhancement but is very sensitive to noises. Low-pass filters are usually employed to suppress the noise, but often lead to the blurred edges. To overcome these problems, a sharpening algorithm for X-ray images based on nonlinear module is proposed. First, we suppress noise of X-ray images by image averaging; then a lookup table, which is used to sharpen X-ray images, is set by the grey difference between the centre pixel and each neighbouring pixel. The new method can sharpen images and simultaneously can have good performance in noise reduction. The experimental results have demonstrated the effectiveness of the proposed method.

Keywords:

• image sharpening
• unsharp masking
• X-ray image
• nonlinear module

The work reported here was funded by the Natural Science Foundation of Shanxi Province, China (no. 2009011020-2) and National Nature Science Foundation of China (no. 61071192).