topic What is the meaning of Realsense depth data?Distance from pixel to the center of the camera or distance of a depth plane? in Software Archive

What is the meaning of Realsense depth data?Distance from pixel to the center of the camera or distance of a depth plane?

Alex_X_ — Thu, 17 Mar 2016 15:37:23 GMT

I used to use kinect v2,it's depth data means the depth of a vertical plane which the pixel belong to.

Dose Realsense work the same way?

From my testing so far, a raw

kfind1 — Thu, 17 Mar 2016 20:10:02 GMT

From my testing so far, a raw depth value is the distance from the point in the scene to the pixel on the image sensor (or equivalent sensing model, when using stereo vision) . I don't think the raw values are perpendicular to the X-Y plane, only after calibration is that true. Until you calibrate, you have to deal with the camera perspective/projection.

On the R200 I then get the device's calibration info and use a StreamCalibration and the Projection class to convert this raw depth to a proper world coordinate XYZ in floating point millimeter units values. This is still with reference to the camera frame - if you wanted a static world reference you would need to find/make the transform between camera and world frame, especially if the camera is moving.

You get the distance form the

jb455 — Fri, 18 Mar 2016 09:50:01 GMT

You get the distance form the camera plane, i.e., perpendicular distance, not a straight line from the object to the camera lens.(is that what you meant?)

So if you had a completely flat object exactly perpendicular to the camera, the depth value should be constant across the face of the object (though in reality it's a bit wobbly due to errors)

Depth returned is the Z

samontab — Sat, 19 Mar 2016 05:28:29 GMT

Depth returned is the Z component of the 3D point with origin in the depth camera's optical center.

In other words, distance to the XY plane, not distance to the center of the camera.

Thank you all, it helps a lot

Alex_X_ — Tue, 29 Mar 2016 17:48:23 GMT

Thank you all, it helps a lot.