基于同态滤波与直方图均衡化的射线图像增强

Ray Image Enhancement Based on Homomorphic Filter and Histogram Equalization

针对同态滤波与直方图均衡化单独进行X射线图像增强时存在的不足,提出了在频域内将同态滤波与直方图均衡化结合使用的思想。首先,对X射线图像进行同态滤波的分频处理;再将得到的低频分量进行全局的直方图均衡化处理;最后,将高频分量跟低频分量进行线性融合。实验结果表明,经过该方法处理的X射线图像,边缘信息更加突出,且整体视觉效果更明亮清晰。通过分析均方根误差和信噪比数据,也证实了该方法能有效地增强X射线图像。

Homomorphic filter and histogram equalization can enhance the image individually, but they still have many disadvantages. In view of the disadvantages,a new algorithm which combines homomorphic filtering with histogram equalization in frequency domain is presented. Firstly,X-ray images are processed separately by using homomorphic filter. Then,the low frequency components are processed with global histogram equalization. Finally,the high frequency components and the low frequency components are linear fusion. The experimental results show that the boundary of X-ray images is very prominent and evident, and the overall visual effect is more bright and clear. Root mean square error and signal to noise ratio data are obtained by analy- sis,which confirmed that the methods can enhance X-ray images effectively.