聚能罩压垮图象的计算机处理

COMPUTER PROCESSING ON SHAPED CHARGE COLLAPSING IMAGE

本文探讨了聚能罩压垮照片的数字图象处理技术。认为利用图象处理的方法,不但可以减少实验数据的判读误差,提高清晰度,而且还可以得到其它方法很难得到的边界曲线方程。

In flash X-ray photograph, most of the explosion phenomena are recorded on the film,when these films images are analysised and measured,the problems will be meet as follows:(1)Measure the coordinate of the image; (2)Image enchancement.In measuring collapsing parameters of the shaped charge,determination of boundaries in the image is very important. For example,in Fig. 1 ,we want to know the accurate positions of boundaries in the image.Before image processing,the photograph can be divided into 12 regions as shown in Fig. 2 for input into the computer. Image numeral matrix is analysised and it is found a lot of noise in the image. In order to reduce noise influence and to recognize the boundary. The method of mean gray level threshold can be used by the following equation:Here ,f(i, j) is the gray level before processing,g(i, j) is the gray level after processing.After above processing,the whole boundary becomes clearer,but some part of its boundaries are zigzagged. The whole boundary curve can be got by curve fitting.The equation of boundary curve is as equation 2 and Fig. 3. The images smoothed by equation 2 are as Fig. 4. The ralative error of boundaries is 1. 56% and the collapsing angle B is 95.In this article, the methods of image enchancement have been used to process the experimental photograph. For example,experimental photograph is got as shown in Fig. 5 and its histogram is shown in Fig. 6. It can be seen from Fig. 6 that its contrast is lower. So the method of histogram equalization is used to process Fig. 5. The process image and its histogram have been got as shown in Fig. 7 and Fig. 8. The isogram of Fig. 7 is shown in Fig. 9.