X射线投影图像中闪烁体缺陷区域的修复

摘要

An extraction method is proposed aiming at artifacts caused by scintillation defects in X-ray projection images. Defective pixels are extracted by extracting the local abnormal points. The normal images are transformed into polar coordinate, and the local abnormal points are extracted to get the mask images with marked defective pixels. Objective data and subjective visual comparison of simulation images validate the effectiveness of the extraction algorithm. The process includes the spreading process along the isolux line and the anisotropic diffusion process. The extraction method is applied. BSCB algorithm is restored into different magnifications of X-ray projection images. Experimental results show that the images quality is improved obviously.%针对X射线投影图像中闪烁体缺陷引起的图像伪影，提出一种缺陷提取算法。采用提取极坐标下局部异常点的方法提取缺陷像素。将本底图像(空扫图像)转化为极坐标形式，提取极坐标下的局部异常像素为缺陷像素，从而得到标记出缺陷像素的掩膜图像。将算法应用于仿真图像的缺陷提取，客观数值和主观视觉2个方面的比较结果验证了该算法的有效性。将梯度信息沿等照度线方向扩散实现图像的修复过程，交叉进行各向异性扩散过程以保证清晰度。对系统采集到的不同放大倍率的X射线投影图像进行缺陷提取，并运用BSCB算法对图像进行修复。实验结果表明，修复后图像的质量得到明显改善。