Effects of blur and scattering on boundary detection of flash radiography
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摘要: 借助蒙特卡罗方法模拟闪光照相过程,研究了模糊和散射因素对边界检测的影响。结果表明:模糊与边界退化量的变化关系依赖于相邻飞层的材料、密度和尺寸;相同客体结构下,模糊越大,边界退化量也越大;客体结构不同,相同模糊下的边界退化量也不同;散直比越大,散射对边界检测结果的影响也越大,当散直比大于50时,散射引起的边界检测误差超过1个像素。Abstract: Owing to the effect of non-ideal factors in the imaging process, X-ray photographic image quality is degraded, resulting in a shift of image boundary position relative to that of the object. In this paper, the Monte Carlo method is used to simulate the flash photography process, and the influence of fuzzy and scattering on the boundary detection is studied. The result shows that the relationship between the blur size and the boundary deviation is dependent on the material, density and size of adjacent layers; under the same object structure, the larger the blur, the greater the boundary deviation; when the object structure is different, the boundary deviation is also different with the same blur size. The greater the ratio of scatter to direct, the greater the effect of scattering on the boundary detection results. When the ratio is greater than 50, the boundary detection error caused by scattering is more than one pixel.
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Key words:
- flash radiography /
- Monte Carlo method /
- image degradation /
- boundary detection /
- fuzzy /
- scattering
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表 1 采用case 1照相布局散直比为9.3下散射对边界检测结果影响
Table 1. Scatter influencing edge detection with case 1 and ratio of scatter to direct is 9.3
direct image/mm total image including scattering/mm absolute error /mm boundaryⅠ 11.235 11.336 0.101 boundaryⅡ 43.962 43.988 0.026 boundaryⅢ 64.026 64.027 0.001 表 2 采用case 1照相布局散直比为37.9下散射对边界检测结果影响
Table 2. Scatter influencing edge detection with case 1 and ratio of scatter to direct is 37.9
direct image/mm total image including scattering/mm absolute error /mm boundaryⅠ 11.201 11.224 0.023 boundaryⅡ 43.958 44.040 0.082 boundaryⅢ 64.061 64.065 0.004 表 3 采用case 1照相布局散直比为58.3下散射对边界检测结果影响
Table 3. Scatter influencing edge detection with case 1 and ratio of scatter to direct is 58.3
direct image/mm total image including scattering/mm absolute error /mm boundaryⅠ 11.124 11.413 0.289 boundaryⅡ 43.948 44.064 0.116 boundaryⅢ 64.055 64.061 0.006 表 4 采用case 1照相布局散直比为101下散射对边界检测结果影响
Table 4. Scatter influencing edge detection with case 1 and ratio of scatter to direct is 101
direct image/mm total image including scattering/mm absolute error /mm boundary Ⅰ 11.288 10.414 -0.874 boundary Ⅱ 43.946 44.149 0.203 boundary Ⅲ 64.048 64.061 0.013 表 5 采用case 2照相布局散直比为1.6下直穿图像与含散射图像边界结果比较
Table 5. Results of scatter influencing edge detection with case 2 and ratio of scatter to direct is 1.6
direct image/mm total image including scattering/mm absolute error/mm boundary Ⅰ 6.150 6.150 0 boundary Ⅱ 21.478 21.479 0.001 boundary Ⅲ 31.539 31.539 0 表 6 采用case 2照相布局散直比为15.9下散射对边界检测结果影响
Table 6. Results of scatter influencing edge detection with case 2 and ratio of scatter to direct is 15.9
direct image/mm total image including scattering/mm absolute error /mm boundary Ⅰ 6.150 6.152 0.002 boundary Ⅱ 21.474 21.482 0.008 boundary Ⅲ 31.539 31.541 0.002 表 7 采用case 2照相布局散直比为23.6下散射对边界检测结果影响
Table 7. Results of scatter influencing edge detection with case 2 and ratio of scatter to direct is 23.6
direct image/mm total image including scattering/mm absolute error /mm boundary Ⅰ 6.151 6.150 -0.001 boundary Ⅱ 21.477 21.477 0 boundary Ⅲ 31.538 31.538 0 表 8 采用case 2照相布局散直比为35.1下散射对边界检测结果影响
Table 8. Results of scatter influencing edge detection with case 2 and ratio of scatter to direct is 35.1
direct image/mm total image including scattering/mm absolute error /mm boundary Ⅰ 6.147 6.150 0.003 boundary Ⅱ 21.478 21.522 0.044 boundary Ⅲ 31.548 31.556 0.008 表 9 case 3情况下直穿图像与含散射图像边界结果比较
Table 9. Results of scatter influencing edge detection with case 3 and ratio of scatter to direct is 6.7
direct image/mm total image including scattering/mm absolute error /mm boundary Ⅰ 11.201 11.189 -0.012 boundary Ⅱ 44.057 44.057 0 boundary Ⅲ 64.231 64.231 0 -
[1] Cunningham G S, Morris C. The development of flash radiography[J]. Los Alamos Science, 2003(28): 76-91. [2] Watson S A, Balzer S, Gossein C, et al. Density measurement errors at DARHT-quantifying a decade of progress[J]. Defense Science Quarterly, Summer 2009: 2-3. [3] 周俸才, 刘瑞根. 用模糊差分滤波法检测闪光辐射照相物体边界[J]. 光电工程, 1996, 23 (s1): 37-41. https://www.cnki.com.cn/Article/CJFDTOTAL-GDGC1996S1006.htmZhou Fengcai, Liu Ruigen. Boundary detection of flash radiograph object with fuzzy differential filtering technique. Opto-Electronic Engineering, 1996, 23 (s1): 37-41 https://www.cnki.com.cn/Article/CJFDTOTAL-GDGC1996S1006.htm [4] 张小琳, 景越峰, 刘军. 基于Facet模型的闪光图像边缘检测[J]. 强激光与粒子束, 2010, 22 (7): 1640-1644. http://www.hplpb.com.cn/article/id/4368Zhang Xiaolin, Jing Yuefeng, Liu Jun. Edge detection method based on Facet model for flash X-ray radiographs. High Power Laser and Particle Beams, 2010, 22 (7): 1640-1644 http://www.hplpb.com.cn/article/id/4368 [5] 崔旭东, 邱春蓉, 刘瑞根. 用标记松弛方法检测闪光图像边缘[J]. 光电工程, 2001, 28 (4): 42-45. https://www.cnki.com.cn/Article/CJFDTOTAL-GDGC200104010.htmCui Xudong, Qiu Chunrong, Liu Ruigen. Detection of flashing image edge with label relaxation method. Opto-Electronic Engineering, 2001, 28 (4): 42-45 https://www.cnki.com.cn/Article/CJFDTOTAL-GDGC200104010.htm [6] 管永红, 刘瑞根, 周俸才. 一种新的闪光照相图象边界检测方法[J]. 光子学报, 1999, 28 (2): 161-164. https://www.cnki.com.cn/Article/CJFDTOTAL-GZXB902.015.htmGuan Yonghong, Liu Ruigen, Zhou Fengcai. A new edge detection method for flash radiographic image. Acta Photonica Sinica, 1999, 28 (2): 161-164 https://www.cnki.com.cn/Article/CJFDTOTAL-GZXB902.015.htm [7] 刘军. 高能闪光照相中的主要物理问题研究[D]. 绵阳: 中国工程物理研究院, 2008: 18-21.Liu Jun. Main problems in high energy flash X-ray radiography. Mianyang: China Academy of Engineering Physics, 2008: 18-21 [8] 刘进, 张小琳, 景越峰, 等. 含系统模糊的闪光照相正向成像技术研究及应用[J]. 强激光与粒子束, 2015, 27: 044003. doi: 10.11884/HPLPB201527.044003Liu Jin, Zhang Xiaolin, Jing Yuefeng, et al. Research and application of forward imaging technology with systemic blur. High Power Laser and Particle Beams, 2015, 27: 044003 doi: 10.11884/HPLPB201527.044003 [9] 刘军, 张绚, 刘进, 等. 高能闪光照相中网栅相机的性能分析[J]. 强激光与粒子束, 2016, 28: 024003. doi: 10.11884/HPLPB201628.024003Liu Jun, Zhang Xuan, Liu Jin, et al. Performance analysis of anti-scatter grid camera in high energy flash radiography. High Power Laser and Particle Beams, 2016, 28: 024003 doi: 10.11884/HPLPB201628.024003 [10] 肖智强, 刘军, 胡八一, 等. 高能闪光照相中陡坡准直体成像性能实验研究[J]. 核电子学与探测技术, 2007, 27 (3): 512-515. https://www.cnki.com.cn/Article/CJFDTOTAL-HERE200703021.htmXiao Zhiqiang, Liu Jun, Hu Bayi, et al. Experimental research of the performance of graded collimators in high energy flash X-ray radiography. Nuclear Electronics & Detection Technology, 2007, 27 (3): 512-515 https://www.cnki.com.cn/Article/CJFDTOTAL-HERE200703021.htm