Hi,
Recently in my project, I needed to lift a point cloud of shape  (n, 3) from an Image of shape (3, H, W), whose RGB color represents the spatial coordinates. I also have a mask with shape (240, 320) to indicate which points I need. I used an indexing operation to lift it:
masked = mask > threshold
point_cloud = img[:, masked].transpose(0, 1)

However, this operation is very slow, took nearly 0.1 seconds. Is there any way to improve the performance here?
Thanks!