随机模式噪声测试图可定制测试卡
这张随机模式（噪音）测试图主要测量纹理清晰度，该卡具有以下主要特点：
1、它包含倾斜的边缘（2:1和4:1对比度）方便与枯叶模式对比。
2、随机模式测试图左右两侧的灰色区域具有相同的密度，可以使用它去除PSD噪音的影响。
3、同时测试图还包含定位标记和16级灰阶补丁。
随机模式噪声测试图可定制测试卡
Details
The Imatest Random Pattern chart for measuring texture sharpness has several key features:
It contains slanted edges (2:1 and 4:1 contrast) for convenient comparisons with the dead leaves pattern.
The gray area to the left and right of the random pattern has the same mean density as the random pattern, allowing it to be used for effective noise PSD removal using the McElvain et. al. technique.
Registration marks and 16 grayscale patches are included. The linear levels used to create the grayscale patches are 0 through 255 in steps of 17 (same as the Siemens Star chart in the draft of the upcoming ISO 12233 standard).
