铸钢件射线检测中缺陷的数字化测量技术研究

为了对铸钢件射线底片中的缺陷实现数字化测量,设计了图像测量模板,采用分离参数的方法,通过模板图像对CCD成像系统进行参数的标定,对图像的径向畸变进行校正.校正后图像的分辨率为5.3LP/mm,最大变形量为0.6像素,达到了亚像素级,相对变形小于0.1%,基本消除了径向畸变,使图像与原胶片平面成线性关系。利用此方法对铸钢件缺陷进行测量表明,只需在相同拍摄条件下依据模板标定的参数,就可以实现图像校正和精确测量。相比其它机器视觉的测量方法,本方法涉及参数少且相互独立,计算过程简单,适用于所有平面图像的CCD面成像测量。

Research on Digitized Measurement Technique to Defects in Steel Casting's Radiography Test

In order to accomplish digitized measurement to defects on steel casting's radiography film,a measurement template is designed in this paper.Through it's image,the CCD imaging system's parameters were demarcated and the radical distortions of image were corrected using a separating parameter's method.After correction,the image's distinguishability is amount to 5.3LP/mm,the largest distortion of image is about 0.6 pixels,is equivalent to amount to subpixel level,and relative distortion is less than 0.1%.the radical distortions is eliminated in substance and the digitized image is linear to original film's size.It is testified that using this method to measure the defects of steel casting,as long as on the same imaging condition,using the former parameters,the correction and accurate measurement of films' images can be achieved.Compared to other measurement means,the method used in this paper involves in less parameters which are independent each other and simpler calculation process.It can be adopted to all of the CCD's surface imaging measurement about plane images.