双近贴式X射线像增强器成像不均匀性的分析与校正

Analysis and Correction for Nonuniformity of the Two Side Proximity of X-ray Image Intensifier Radiography

分析了双近贴式X射线像增强器响应不一致性的产生机理,对每个像元建立了光电响应的数学模型.基于该模型,提出了一种改进的多点校正算法.该算法将对数曲线模型转化为线性响应模型,通过基于最小二乘法的两点拟合算法对图像数据进行校正.对比分析了校正前后图像的背景标准差及灰度分布曲线,实验结果验证了该方法的有效性.

By theoretical analysis of the cause for the two side proximity of X ray image intensifier response non-uniformity, a mathematics model of each pixel channel was set up and an improved multi-point correction algorithm was presented. The nonlinear response data was transformed to linear response by the proposed algorithm and the two-point algorithm based on least mean-square method was used to correct the image data. The standard deviations for images and the gray distributed curve were given before and after the correction. The non-uniformity correction capability of the presented solution was validated by experimental results.