测试卡展示

测试卡说明

带片测试图是专门为检测分辨率特性和TV摄像机以及TV传输系统“串色”干扰而研发的。测试图一个波带片分布满整个图像区域，其中图像上的环以线性增加的空间频率向外扩展。网格线标志着垂直和水平方向上的空间频率，中心位置2MHz，边缘位置1MHz。图像上水平方向边缘的空间频率可以达到8MHz，垂直方向边缘的空间频率达到6MHz。测试图的角落的空间频率为10MHz。

带片用于确定的TV摄像机和TV传输系统的以下特征：

· 水平，垂直和对角方向的分辨率

· 分辨率取决于扫描的位置

· 水平和垂直光圈校正效果

· 照相机的扫描光束的象散（阀摄像机）

· 带片和电视光栅对应彩色显像管荫罩结构之间干涉的影响。

· PAL编码的效果（例如“串色”）

在水平和垂直方向上照相机（或测试图）运动过程中反应：动态分辨率，时间干扰干扰

该带片测试卡特别适合与电视信号滤波器的多维测量装置（水平、垂直以及如果可能在时间上）一同使用。这些装置可以是TV摄像机镜头光圈矫正器，也可以是标准PAL解码器（带线延迟）和梳妆滤波PAL解码器。带片也可以被使用在MAC系统（根据色彩线序传输）的预处理和预过滤效果的测定。带片测试图已经被证实可以可靠的测量CCD摄像机。

English Introduction

The zone plate test chart is designed for checking the resolution characteristics and “cross color” interferences of TV cameras and TV transmission systems. The test chart shows a zone plate over the whole image area where the spatial frequency of the rings has a linear increase towards the edges. The line grid marks the spatial frequency in vertical and horizontal direction , with 2 MHz in the center area and 1 MHz towards the edges. In horizontal direction spatial frequency reaches 8 MHz and in vertical direction 6 MHz at the edges of the test chart. In the corners of the test chart spatial frequency is 10 MHz.

The zone plate is used to determine the following characteristics of TV cameras and TV transmission systems:

· resolution in horizontal, vertical and diagonal direction

· resolution depending on the location of scanning

· effects of horizontal and vertical aperture corrections

· astigmatism of the scanning beam of the camera (valve cameras)

· effects of interferences between the zone plate and the television raster resp. the shadow mask structure of color picture tubes

· effects of PAL coding (e. g. “cross color”)

reaction during movement of the camera (or the test chart) in horizontal and vertical direction:

dynamic resolution, temporal interference interferences

The use of the zone plate is particularly suitable with measuring devices where the television signal is filtered multi dimensionally (horizontally, vertically and if possible temporally). These can be aperture corrections of TV cameras but also standard PAL decoders (with line delay) and comb-filter PAL decoders. The zone plate can also be used for the determination of pre- and postfiltering effects with MAC-systems (with line-sequential color transmission). The zone plate test chart has proved particularly reliable for testing CCD cameras.