X射线光栅相衬成像拼接缝消除算法

针对X射线光栅相衬成像拼接过程中出现的拼接缝问题,提出一种基于改进的中值滤波结合全变分平滑模型的拼接缝消除方法。首先利用方差的全局亮度调整方法消除待拼接图像间亮度不均,获取亮度均匀图像。然后通过改进的中值滤波对拼接缝两侧灰度值进行修正,以抑制灰度突变的干扰;再利用全变分平滑模型对修正后的图像进行平滑,使拼接缝过渡光滑。最后对平滑后图像进行增强,获得增强后的大视场图像。实验结果表明,所提方法在保持图像边缘细节的同时,能够有效消除拼接缝隙,提高了拼接图像质量。

A Seam-Line Removal Method for Grating-Based X-Ray Phase Contrast Imaging

In view of the seam-line problem exists in grating-based X-ray phase contrast imaging, this paper proposed a method to remove the seam-line based on the improved median filtering which is combined with the total variation smoothing model. Firstly, global brightness adjustment algorithm based on variance was used to obtain the uniform brightness images by eliminating the uneven brightness between the images to be stitched. Then, in order to suppress the interference of the gray level mutation, the gray value on both sides of the stitching was modified through improved median filtering. Moreover, in order to eliminate the seam-line smoothly, the total variation smoothing model was solved in the corrected image. Finally, the smoothed image was enhanced to obtain the large field of view image. The results show that the proposed method can effectively eliminate the seam-line while maintaining the edge details of the image, and improve the quality of the stitched image.