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2018-05-16 09:33:04 -0600 received badge  Supporter (source)
2018-04-29 11:00:59 -0600 marked best answer Row and Col problem when Mat represents 3d point cloud

The row and col of a Mat to represent 3d point cloud in OpenCV is N * 3, N is the number of the points in the cloud and 3 is the x, y, z coordinate respectively. For example, when I use method loadPLYSimple to load data from PLY file I will get N * 3 Mat, when I use the Flann KDTREE, I need to pass N * 3 Mat as the parameter... But the problem is that when I try to perform a transformation on the data, such as rotation. If we have a 3 * 3 rotation Mat R, and the points Mat pc N * 3, the common way is just R * pc. However, pc is N * 3, so we need to do some extra transpose work. I'm not familiar with OpenCV, I just want to know if there is any better way to do that instead of doing the transpose work each time? Or maybe there is something which I do not understand hidden behind?Thanks.

2018-04-29 11:00:59 -0600 received badge  Scholar (source)
2018-04-29 11:00:57 -0600 commented answer Row and Col problem when Mat represents 3d point cloud

Thanks. I just realize that store Mat data in this way (N*3) can be more efficient when accessing memory.

2018-04-24 16:40:23 -0600 received badge  Enthusiast
2018-04-15 12:52:36 -0600 commented answer Row and Col problem when Mat represents 3d point cloud

Thank you, that's what I mean the "extra transpose work". I wonder why not just use 3 * N Mat to represent 3d points to

2018-04-15 10:01:55 -0600 received badge  Editor (source)
2018-04-15 10:01:55 -0600 edited question Row and Col problem when Mat represents 3d point cloud

Row and Col problem when Mat represents 3d point cloud The row and col of a Mat to represent 3d point cloud in OpenCV is

2018-04-13 17:03:47 -0600 asked a question Row and Col problem when Mat represents 3d point cloud

Row and Col problem when Mat represents 3d point cloud The row and col of a Mat to represent 3d point cloud in OpenCV is