DR平板探测器图像校正方法研究

Research on DR flat panel detector image correction method

针对数字射线(digital radiography,DR)平板探测器各像元不一致造成的图像灰度值不均匀问题,建立基于统计分析的图像校正方法。以XRPad24336平板探测器为对象,首先获取原始空场图像和暗场图像,讨论基于暗场图像的偏移校正,基于空场图像灰度值中位数的增益校正方法;然后根据标准ASTM-E2597的定义,对坏像素进行标记和修正;最后以标准差信噪比(SNR)来评价图像校正后效果。经实际工件透照分析表明:原始图像经校正后,图像质量得到有效提高。该校正方法具有普遍适用性,可为其他DR平板探测器图像校正提供参考。

In order to solve the problem of uneven gray value caused by the inconsistency of each pixel in digital radiography(DR)plate detector,an image correction method based on statistical analysis is studied.With XRPad24336 flat panel detector as the object,the original empty field image and dark field image were first obtained,and the offset correction method based on dark field image and gain correction method based on median gray value of empty field image were discussed.Then,the bad pixels are marked and corrected according to the definition of standard ASTM-E2597.Finally,the standard deviation SNR was used to evaluate the effect after image correction.The analysis of the actual workpiece shows that the quality of the original image is improved effectively after the correction.The correction method studied in this paper is universal and can provide reference for image correction of other DR flat detector.