MotionBERT icon indicating copy to clipboard operation
MotionBERT copied to clipboard

What is the unit of 3d keypoints

Open jk456445 opened this issue 1 year ago • 3 comments

I have the 3d keypoints value of a picture, but I am curious about the unit of these values, whether it's in pixels or something else. image

jk456445 avatar Jan 02 '24 11:01 jk456445

Author needs to confirm but from my understanding, the 0 and 1 are between [-1, 1] and the 2 is the keypoint confidence score.

valentin-fngr avatar Jan 18 '24 22:01 valentin-fngr

I would also be glad to know the answer to the post's question. These are almost certainly coordinates in three-dimensional space. At first I thought that the skeleton was inscribed in a cube with a side of length 2 (from -1 to 1), but in one of the predictions I saw that the minimum value is less than -1 (-1.06). And it puzzled me :)

Alloxxa avatar Jan 22 '24 15:01 Alloxxa

I believe you can find the code for the scaling in the following file: motionbert\lib\utils\utils_data.py functions: crop_scale() and crop_scale_3d()

It looks like the keypoints are scaled to [-1,1] based on the bounding box (min and max coordinates in all axes).

RojanAsl avatar Apr 30 '24 08:04 RojanAsl