虽然射线检测是通过观察胶片上影像的特征来对缺陷进行定性、定位和定量的，但在大多数情况下不能准确确定缺陷的自身高度和深度等一些参数。文章运用几何原理，通过数字化胶片上本影缺陷的影像特征，确立了缺陷在工件中的深度和自身高度的一种计算方法。同时，根据影像的特点对缺陷的水平位置做了适当的修正。最后通过具体实例证实了此方法的应用价值。

Although radiographic testing determines the nature of disfigurement through image on film, however usually, it cannot identify parameter of vice correctly, such as height and depth, and it has certain effect for practical work. This essay afforded a method of measuring height and depth of defect through the character of image on film using geometry principle. At the same time, the paper revised appropriately horizontal position of imperfection according to the character of image. Eventually, it proved further applicability of the means through specific example.