由边界退化确定模糊尺寸

在高能闪光照相流体动力学实验中,模糊问题严重影响诊断结果的精度。模糊图像的边界检测结果与真实边界之间往往存在位置偏移,称为边界退化量。在照相布局和客体确定的条件下,模糊尺寸越大,边界退化量越大。利用边界退化量与模糊尺寸的这一关系,提出一种从边界检测中测量系统模糊尺寸的新想法,从闪光照相成像物理过程角度阐释了方法的原理,然后通过数值实验分析了方法的处理过程,建议测量实验利用倒锥准直器对球形客体成像。模拟结果表明:采用该方法模糊函数的FWHM误差小于1个像素。最后借助数值模拟对台阶客体照相实现了对模糊尺寸测量结果的验证。

Determination of blur size of radiographic system from boundary deviation

In high energy flash radiography, the blur is a key problem seriously affecting the accuracy of diagnosis. Due to blurring the detected boundary from the image has a deviation from the true value. The larger the blur size, the larger the boundary deviation with the radiographic layout and the structure of object fixed. On this basis, a new method for determining the blur size of the radiographic system from boundary deviation is presented in this paper. The principle of the method is explained from the physical process of flash radiography. The method is applied to the simulated images, and the measurement of the blur size is validated by means of radiographing the step object. It is shown that the FWHM error of the fuzzy function is less than one pixel, and the backward cone collimator used to photographing the spherical object is recommended.