X射线线阵探测器校正与滤波

针对X射线线阵探测器像素响应不均而造成X射线图像产生竖条纹，以及由探测器本身和外界产生噪声干扰的问题，提出了一种新型的校正与滤波模型，解决了传统校正方法因忽略噪声影响而使得校正完成后数据波动较大的问题。结合X射线特性及X射线线阵探测器的成像原理，分析了像素响应不均时的输出特性及噪声，建立了改进的两点校正算法与基于偏微分方程的半隐式差分滤波模型。实验证明，分辨率为19 216的X射线线阵探测器在经过该模型校正后，有效地解决了像素响应不均的问题，抑制了噪声的影响，在位深为16 bit的情况下，平均均方误差低于五个灰度级，提高了X射线图像检测的质量。

Calibration and filtering of X-ray line array detector

To overcome the problems of X-ray image's vertical stripes caused by uneven response of X-ray linear detector's pixels and the noise interference produced by detector and outside, a new calibration and filtering model was proposed. It solved the problem that traditional calibration result was very volatile with ignoring noise. By combining X-ray's features and X-ray linear array detector's imaging principle, the output characteristic and noise were analyzed when the pixel responded unevenly. Besides, the calibration and filtering model was built. Improved-two-point calibration algorithm was used to calibrate the image and semi implicit difference method based on partial differential equation was used to smooth the noise. Experiment results show that the unevenly response of X-ray linear array detector with a resolution of 19 216 was eliminated, and the influence of noise was suppressed. In the case of 16 bit per pixel,the mean square error was below five gray level, it improves the quality of X-ray image detection.