如何获得D435的RGB相机和深度相机之间的相对位置？

D435是一款Strereoscopic型相机。
这意味着它有一个RGB传感器和一对红外传感器（左和右）。
左和右IR成像器用于构建深度图像。
如果您的目标是对齐多个RealSense相机但不需要精确同步它们的流，我想知道'Multicam'示例程序是否可以满足您的需求。
master上的librealsense / examples / multicam·IntelRealSense / librealsense·GitHub
如果您需要将D435与非RealSense设备对齐，那么多摄像头硬件同步将是最佳选择。
https://realsense.intel.com/wp-content/uploads/sites/63/Multiple_Camera_WhitePaper_rev1.1.pdf
值得注意的是，使用D435启动同步时，您还需要额外的D415相机作为同步触发脉冲发生器或使用外部信号发生器。



以下为原文

The D435 is a Strereoscopic type camera.  This means that it has an RGB sensor and a pair of infrared sensors (left and right).  The left and right IR imagers are used to construct a depth image.
 
If you are aiming to align more than one RealSense camera but do not need their streams to be precisely synchronized, I wonder if the 'Multicam' sample program might meet your needs.
 
librealsense/examples/multicam at master · IntelRealSense/librealsense · GitHub
 
If you are needing to align a D435 with a non-RealSense device, then multi-camera hardware sync would be the way to go.
 
https://realsense.intel.com/wp-content/uploads/sites/63/Multiple_Camera_WhitePaper_rev1.1.pdf
 
It is worth bearing in mind though that with a D435, to initiate the syncronization you would also need an additional D415 camera to act as the sync trigger pulse generator or use an external signal generator.

是的，Extrinsics对象包含两个传感器之间的平移，以米为单位。
要获得它，根据您使用的语言，您需要执行以下操作：
var extrinsics = depthStream.GetExtrinsicsTo（colourStream）;
或者，IIRC，校准工具/ api包括用于从设备输出校准数据的命令行app。



以下为原文

Yes, the Extrinsics object contains the translation between the two sensors in metres.
To get it, depending on what language you're using, you'll need to do something like this:
 
var extrinsics = depthStream.GetExtrinsicsTo(colourStream);
 
Alternatively, IIRC, the calibration tools/api includes a command line app for outputting calibration data from a device.

谢谢，我会试一试。
实际上我想将D435与投影仪对齐。
目前，我找到了一种将RGB传感器与投影仪对齐的方法。
所以我想知道将D435与投影仪对齐是否可以直接对齐RGB传感器。



以下为原文

thank you, I will take a try.
 
Actually I want to align a D435 with a projector. Currently I find a method to align a RGB sensor with a projector.
 
So I want to know whether it is OK to align a D435 with a projector directly just align the RGB sensor.

谢谢，我会试一试。
那么D435中两个传感器之间的位置是这样的吗？
RT = [1 0 0 extrinsics 
0 1 0 0 
0 0 1 0 
0 0 0 1]



以下为原文

thank you, I will take a try.
 
So the position between the two sensors in D435 is just like this?
 
RT=[1 0 0 extrinsics
        0 1 0 0
        0 0 1 0
        0 0 0 1]

英特尔的深度测试指南说明了外部投影仪：“投影仪不需要与深度传感器共存。如果需要，也可以移动或摇动投影机，但不需要它”。
https://www.intel.com/content/dam/support/us/en/documents/emerging-technologies/intel-realsense-technology/BKMs_Tuning_R...
以下是有关外部投影仪的指南的其余部分。
**********
一个。
虽然内部投影机非常好（如下图所示），但它的功率确实非常低，而且不是为照亮非常大的房间而设计的。
因此，添加一个或多个额外的外部投影仪有时是有益的。
D4xx相机将受益于投射到没有固有纹理的场景上的任何额外纹理，如平坦的白色墙壁。
通常情况下，当您使用任何外部投影仪时，只要它连续打开或在> 50KHz闪烁时，D4 VPU就不需要进行调整，以免干扰传感器的卷帘快门或自动曝光特性。
湾
外部投影仪在低功耗并不重要的固定安装中非常有用，例如静态箱式测量设备。
通过在物体附近添加照明，也可以照亮远处的物体。
C。
关于特定的投影图案，我们建议使用5000到300,000个半随机点。
我们通常建议尺度不变的模式。
这意味着如果投影仪和深度传感器之间的间隔发生变化，那么深度传感器仍会在很大的距离范围内看到纹理。
d。
可以使用可见光或近红外光（范围从约400-1000nm），尽管我们通常建议将850nm作为人眼看不见的良好折衷方案，同时红外传感器仍然可以看到大约15-
灵敏度降低40％，具体取决于所使用的传感器。
即
使用基于激光的投影仪时，采取一切必要手段来减少激光散斑非常重要，否则会对深度产生不利影响。
非相干光源将在深度噪声方面产生最佳结果，但通常不能在远距离产生高对比度图案。
即使采用所有散斑减少方法，看到被动目标或LED投影仪的深度比基于激光的投影仪好30％以上也是不常见的。



以下为原文

Intel's depth testing guide says about external projectors: "Projectors do not need to be co-located with the depth sensor.  It is also acceptable to move or shake the projector if desired, but it is not needed".
 
https://www.intel.com/content/dam/support/us/en/documents/emerging-technologies/intel-realsense-technology/BKMs_Tuning_R…
 
Here is the rest of the text from the guide about external projectors.
 
**********
 
a. While the internal projector is very good (shown below), it is really quite low power and is not designed to illuminate very large rooms. It is therefore sometimes beneficial to add one or more additional external projectors.  The D4xx camera will benefit from any additional texture projected onto a scene that has no inherent texture, like a flat white wall.  Ordinarily, no tuning needs to be done in the D4 VPU when you use any external projectors as long as it is on continuously or flickering at >50KHz, so as not to interfere with the rolling shutter or auto exposure properties of the sensor.
 
b. External projectors can be really good in fixed installations where low power consumption is not critical, like a static box measurement device.  It is also good for illuminating objects that are far away, by adding illumination nearer to the object.
 
c. Regarding the specific projection pattern, we recommend somewhere between 5000 and 300,000 semi-random dots. We normally recommend patterns that are scale invariant.  This means that if the separation between the projector and the depth sensor changes, then the depth sensor will still see texture across a large range of distances.
 
d. It is possible to use light in visible or near-infrared (ranging from ~400-1000nm), although we normally recommend 850nm as being a good compromise in being invisible to the human eye while still being visible to the IR sensor with about 15-40% reduction in sensitivity, depending on the sensor used.
 
e. When using a laser-based projector, it is extremely important to take all means necessary to reduce the laser-speckle or it will adversely affect the depth.  Non-coherent light sources will lead to best results in terms of depth noise, but cannot normally generate as high contrast pattern at long range.  Even when all speckle reduction methods are employed it is not uncommon to see a passive target or LED projector give >30% better depth than a laser-based projector.

我不认为除了数据表中的内容之外，还有其他数字。
我相信（但你应该仔细检查）：RGB相机在IR1的左边15mm ...... IR2在右边50mm。
我认为Viewer将基线的中心作为零点...因此RGB在-42 mm处。
如果您正在使用外部分析...并且想要将数据组合或将数据与Realsense结果进行比较，则如果您没有使用相机的零点作为您的原点，则需要翻译（并可能旋转）您的数据
数据宇宙。
从Viewer中获取深度数据时，深度数据已经与IR1对齐。



以下为原文

I don't think there are any numbers for this other than what is in the datasheet.
 
I believe (but you should double check):  the RGB camera is 15mm to the left of IR1... IR2 is 50mm to the right.  I think the Viewer takes the center of the baseline as the zero point... so RGB is at -42 mm.
 
If you are using external analysis ... and want to combine data or compare data with the Realsense results, you need to translate(and possibly rotate) your data if you aren't using the zero point of the camera as the origin of your data universe.
 
The depth data is already aligned to IR1 when you get it from the Viewer.