What is length unit of point cloud data captured by Intel Realsense SR300 or R200? such as meter or centimeter or millimeter?

[dwang40]

I need to compute the volume of polygon mesh. So i need to know actual unit of X/Y/Z data captured by SR300/R200 device firstly. Appreciate your info very much.

[MartyG · Accepted solution]

Here are the full data sheets for the SR300 and R200.

SR300

https://software.intel.com/sites/default/files/managed/0c/ec/realsense-sr300-product-datasheet-rev-1-0.pdf https://software.intel.com/sites/default/files/managed/0c/ec/realsense-sr300-product-datasheet-rev-1-0.pdf

R200

https://software.intel.com/sites/default/files/managed/d7/a9/realsense-camera-r200-product-datasheet.pdf https://software.intel.com/sites/default/files/managed/d7/a9/realsense-camera-r200-product-datasheet.pdf

Edit: according to this extract from the SR300 data sheet, mm seems to be the appropriate measurement unit.

[dwang40]

Hi Marty, thanks a lot！It is helpful.

BTW, i am confusing now that which planar it is when I capture a 3D polygon mesh obj. Is it XZ planar or XY planar? By default, it should be XY planar. But per my investigation to those XYZ verteices data, it looks that the captured surface is XZ planar. Could you please show me the right info? At the same time, I will also take a look at those datasheet. Thanks again.

[MartyG]

This link describes the camera as using the XY planar.

https://software.intel.com/en-us/articles/realperspective-head-tracking-with-intel-realsense-technology https://software.intel.com/en-us/articles/realperspective-head-tracking-with-intel-realsense-technology

This link about creating point clouds with the camera also uses the XY plane.

https://software.intel.com/en-us/articles/intel-realsense-technology-and-the-point-cloud Intel® RealSense™ Technology and the Point Cloud | Intel® Software

[dwang40]

Hi Marty,

Thanks for your info.

After my investigation, I found that things are not as described in the datasheet. Firstly, I captured a piece of wall by R200 and save the point cloud data in an .obj file . Then I run some experiments against the obj file. Here is my conclusion.

1. I use a test application to measure the captured object (wall). By measure its four corners, I found the Y component value is almost same at all those four points. This means that the planar should be XZ, instead of XY planar.

The tool's reference source code for the points clicking and measuring can be found here: http://www.pointclouds.org/documentation/tutorials/ground_based_rgbd_people_detection.php Documentation - Point Cloud Library (PCL)

It is appreciated that anyone may join the discussion.

[MartyG]

Thanks so much for sharing your experience with the community!