【摘要】 由于平板探测器对有无试件射线能谱响应的灵敏度不同,致使利用射线透照成像对试件投影估计的对比度降低,影响了对细节的可检出性。通过分析射线成像检测的数理模型,提出等效能谱透照成像方法,对探测器灵敏度进行校正。利用无缺陷的高密度材料等被检试件,进行背景成像,实现在有无试件情况下的探测等效能谱成像。与常规校正法对焊接板进行实验对比研究结果表明,等效能谱法增强了成像的可视化效果,通过像质计灵敏度实验,其对比度灵敏度提高了20~40灰度级;提高了检测中诸如未焊透和裂纹等微小细节的可检出性。更多还原

【Abstract】 The contrast of testing piece projection and detectable ability of piece′s feature is reduced by means of estimating the testing piece projection from the system image,because the detector sensitivity is different for X-ray energetic-spectrum with or without testing piece.The image method of equivalent energetic-spectrum is put forward,and applied in correcting the detector sensitivity by analyzing the mathematical model of X-ray radiography.In order to implement detector equivalent energetic-spectrum image with or without piece,the high-density material without defects replaces the testing piece to capture the background image.The experimental research for weld-plate between methods of convention and equivalent energetic-spectrum is made.The result indicates that the visible effect of image is improved and the contrast sensitivity increases 20～40 gray level on image quality indicator(IQI);The attentive detectability of fine feature(such as:faulty-fusion and crack) is improved in testing.更多还原