D435系统地高估了Z-Depth

你用的是什么分辨率？
由于分辨率降低，深度误差会增加，因此建议在D435上使用至少848x480的分辨率，在D415上使用1280x720（请参阅下面英特尔调谐指南中的图像 - 左键单击它以全尺寸查看）
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以下为原文

What resolution are you using please?  Depth error can increase as resolution reduces, so it is recommended that a resolution of at least 848x480 is used on D435 and 1280x720 on D415 (see the image below from Intel-s tuning guide - left-click on it to view in full size).
 

嗨Marty，谢谢你的及时跟进。
我遵循Intel-RealSense-Depth-PostProcess.pdf和BKMs-For-Tuning-RealSense_D4xx_Cameras_WP_1.7.pdf中的建议。
默认视觉预设英特尔.Realsense.CustomRW.exe -g重置为黄金标准工厂848x480没有后期处理。
我已经尝试打开所有后处理器（除了抽取），没有任何变化。由于我的应用程序需要识别薄的障碍（花茎），我宁愿尽可能避免抽取。
我从BKM得知，3米处的误差约为35毫米，但Z系统地高估了，当我预计读数会在3米左右（上下）时徘徊。
这本身不是问题;
如果所有相机都像这样，那很容易纠正。
我担心的是我的设置在某些方面是不正确的。



以下为原文

Hi Marty, thanks for the prompt follow-up.
I'm following the recommendations in Intel-RealSense-Depth-PostProcess.pdf and BKMs-For-Tuning-RealSense_D4xx_Cameras_WP_1.7.pdf.
 

• Default visual preset
  
• Intel.Realsense.CustomRW.exe -g to reset to golden standard factory
  
• 848x480
  
• No post-processing. I've tried turning all the post-processors on (except decimation), nothing changes.
  

As my application needs to recognise thin obstacles (flower stalks), I'd prefer to avoid decimation if at all possible.
I know from the BKM that the error at 3m is around 35mm but the Z is systematically over-estimated, when I would have expected the readings to wander around 3m (above and below).
This isn't a problem per se; if all cameras behave like this it's easily corrected. My worry is that my setup is incorrect in some way.

你确定你有100个测量值吗？
如果您进行了少于或超过100次测量并且将所有测量值相加，然后将总和除以固定值100以获得距离的平均值，则会使结果偏斜。



以下为原文

Are you sure you have 100 measurements?  If you had less or more than 100 measurements and were adding up all the measurements and then dividing the total by a fixed value of 100 to get the average of the distance, that would skew the result.

我重复了实验，记录了每个测量的时间戳，参见附件.XLS。
真实距离500,1,000,1,500等是从相机的玻璃上用钢尺测量的。
这是我的测试安全带的屏幕截图，同时测量为1'500mm：
仅供参考，在底部，您可以看到第424列的值在1'000mm;
地板平坦到1米，然后Y按预期几乎垂直增加，表明木制目标。
红十字表示障碍物的位置，I.E。
下一个像素高出30mm的第一个像素。
测量值是行240列424处的原始范围值，摄像机的中心（真实摄像机中心实际上是239.5,423.5但是半个像素是无关紧要的）。
出乎意料的大错误似乎呈指数级增长：
有趣的是，红色趋势线的截距非常接近零，这意味着Z焦点离玻璃不远。
所以，将这个问题与我的相关焦点问题合并，https：//communities.intel.com/thread/128141
根据这些数据，Z焦点在哪里？为什么误差随距离增加？     
D435RangeProblem.xlsx 
32.0 K.



以下为原文

I've repeated the experiment, logging every measurement, with its timestamp, see attached .XLS.
The true distances 500, 1'000, 1'500 etc are measured from the camera's glass, with a steel ruler.
Here's a screenshot of my test harness whilst measuring at 1'500mm:

FYI, at the bottom, you can see the values for column 424 at 1'000mm; the floor is flat out to 1 metre and then the Y increases almost vertically as expected, indicating the wooden target.
The red cross indicates where the obstacle is, I.E. the first pixel where the next pixel is >30mm higher.
 
The measurements are the raw range values at row 240 column 424, the centre of the camera (the true camera centre is actually 239.5, 423.5 but half a pixel is insignificant).
 
The unexpectedly large error seems to increase exponentially:

Interestingly, the intercept of the red trend line is very close to zero, which implies that the Z focal point isn't far from the glass.
 
So, merging this question with my related focal-point question, https://communities.intel.com/thread/128141
 

• From this data, where is the Z focal point?
  
• Why does the error increase with range?
  

•   D435RangeProblem.xlsx 32.0 K