How to color 3D point cloud with camera image?

Question

• Purpose: to paint (or apply color) the corresponding points in a point cloud with image pixel
• Given: 3D point cloud, thermal images with extrinsic info (position, direction) and FOV

I have a 3D laser scanner which can generate a 3D point cloud. This scanner has a panoramic camera so it automatically generates a colored point cloud. What I wanna do is to change this color information into thermal image to check the object's 3D thermal information.

I thought there might be plenty of libraries or tools but I couldn't find exactly what I wanted. The point cloud is pcd or txt format and the file size is more than a GB (this also is a problem...), and I'm implementing the codes using python but if unavoidable to use C++ than I'll try to.

What would be the best way to approach this problem? Any comments or helps would be great!

Answer 1

Texture mapping is a more appropriate word rather than coloring.

The pcl method - textureMeshwithMultipleCameras - can be used in this situation.

• One of examples using this method

  • https://github.com/PointCloudLibrary/pcl/issues/2830

• standalone texture mapping code

  • https://github.com/otherlab/pcl/blob/master/gpu/kinfu_large_scale/tools/standalone_texture_mapping.cpp

• python example - wrapper of this method

  • https://github.com/iory/texture-mapping