Three-dimensional coordinate system registration

[tguan]

I am using SR300 to get RGB-D images of face,i made a three-dimensional coordinate system on the face ,and i want to registrate it with the three-dimensional coordinate system of the camera,in order to get the pose of face .

So i want to konw howto get the three-dimensional coordinate system information of SR300.

[MartyG]

On the '2016 R2' and '2016 R3' SDKs, 2D depth image coordinates are converted to 3D world coordinates with the instruction ProjectDepthToCamera.

https://software.intel.com/sites/landingpage/realsense/camera-sdk/v1.1/documentation/html/index.html?projectdepthtocamera_pxcprojection.html Intel® RealSense™ SDK 2016 R2 Documentation

If you wish to track the face specifically in the R2 or R3 SDK, there are 78 face 'points of interest' in the SDK's facial system whose position is provided in image and world coordinates.

https://www.intel.co.uk/content/www/uk/en/support/articles/000006099/emerging-technologies.html Recognition Capabilities of the Intel® RealSense™ Camera

In SDK 2.0, the instruction rs2_deproject_pixel_to_point is used to convert 2D image points to 3D world points.

https://github.com/IntelRealSense/librealsense/blob/5e73f7bb906a3cbec8ae43e888f182cc56c18692/include/librealsense2/rsutil.h# L46 librealsense/rsutil.h at 5e73f7bb906a3cbec8ae43e888f182cc56c18692 · IntelRealSense/librealsense · GitHub

[tguan]

Maybe my expression was not clear.

I want to know how to get the Oc-XcYcZc of SR300(c means camera)：Origin coordinates and x, y, z, axis vector.

I will do a registration between the camera three-dimensional coordinate system with the three-dimensional human face coordinate system build by my self,so i want to know the Oc-XcYcZc of SR300.

[MartyG]

In the 2016 SDKs, the 0,0,0 3D origin is at the center of the depth camera.

https://software.intel.com/sites/landingpage/realsense/camera-sdk/v1.1/documentation/html/index.html?doc_essential_coordinate_systems.html Intel® RealSense™ SDK 2016 R2 Documentation