几何失真测试卡（畸变测试卡）

镜头畸变（Lens distortion）是一种造成图像边缘附近的直线变成曲线的像差。它会给建筑拍摄和摄影测量造成问题。zui简单的近似表达式，ru = rd + krd3，ru是未发生畸变的图像光学中心到某点的半径，rd是畸变扭曲后的中心到该点的半径。根据k的符号不同，畸变可以是“桶形”或“枕形”。

几何失真测试卡（畸变测试卡）

镜头畸变和畸变修正系数都可以在Imatest distortion中计算，其中还包括五阶和正切/反正切的畸变模型。SFRplus项目可以显示畸变损失了多少细节，以及对锐度和其他一些因素的影响。畸变zui严重的是广角镜头、远摄镜头和变焦镜头。畸变在近摄图像中往往比正常距离的图像更严重。畸变可以很容易地用软件修正。

用于手机、数码相机、电脑摄像头、笔记本摄像头，车载摄像头的几何失真、畸变指标测试 The test chart is designed for operational adjustment and control of TV cameras. The circles permit rough visual appraisal of scan linearity. The lines serve the purpose of adjusting registration. The wedges serve the purpose of resolution appraisal. 功能描述 A grid structure consisting of 17 horizontal and 23 vertical lines is arranged on a white background forming 18x24 squares. 2 vertical grid lines each divide the outer 2 vertical square rows in the middle. One horizontal grid line each divide the outer horizontal square rows in the middle. The width of the grid lines is 0.13% of the picture width. The large circular line has a diameter of 83 1/3% of the picture height, the 5 small circular lines have a diameter of 25% of the picture height. 2 resolution wedges are arranged in the large circle at angles of 0° and 90°, corresponding to signal frequencies of 2- 10MHz. (The marking ends at 8 MHz and 800 lines.)