According to this process , the key technology which including the characteristic measurement of surface , the pretreatment of data getting by line scan , the character expression and fitting of curve and surface , the characteristic identify of surface and translation from the model of surface to cad 对实物反求过程中的各关键技术作了研究，包括：曲面的特征测量、逐行扫描测量数据的预处理、曲线曲面的特征表示及其拟合、曲面的特征识别以及曲面模型向cad模型的转化。
Current tv system has two types : one is the 60hz based system , the other is the 50hz . the phenomenon of large area flicker is not obvious in the 60hz based system , so the scanning converter uses the way of converting the 60hz and 50hz based interlaced scanning signal to 60hz based progressive scanning signal . employing this way the converter can not only reduce the large area flicker and interline twitter , but erase the raster and display finer and smoother pictures 现行的电视制式有60hz和50hz系统两种，在60hz系统里，大面积闪烁不是很明显，因而本扫描转换器采用将60hz和50hz的隔行扫描信号统一处理成60hz的逐行扫描信号的方法，这样可一方面使大面积闪烁和行间闪烁都比较轻，又可消除行结构，重现细腻图像。
At first , bubble flow image is acquired using laser and incandescence lamp respectively as light source and using ccd . according to different optics - dispersion character , threshold segmentation method is proposed to identify gas from the gas - water flow , which make steadfast base for further calculate void fraction . the precision of threshold directly affect the calculate precision of void fraction 文中分别采用激光片光源和影视灯照明，采用逐行扫描数字ccd摄像机获取气泡的流动图像；根据气泡和水对光的反射特性不同，提出采用阈值法识别图像中的气泡和水，从而为进一步计算掺气浓度打下坚实的基础。
