This is very basic (3D) math.

Once you have the equations for the 3 planes (easiest for xy, xz and yz), you have to find the vertical line from each plane to each point of your point cloud. The point where the vertical line of some point crosses the plane (the footpoint) is the projection of this point.

For the xy, yz and yz planes this is easy-peasy: simply ser the 3rd coordinate to zero. (z for the projection to the xy plane, and so on.)

Hope this helps

Assuming , you have a tool in mind :

Take 3 slices -like how Prof Dreher has mentioned and reconstruction using Radon or back projection (FBP)

Thank you for your time and help, actually i'm working with matlab the problem that i have is when i try to get the point cloud of a depth map i have to be connected with kinect but for me i have a dataset of depth images.

Well Ilham ,

So , the point of cloud is per slice (not available ) can you get the RGBD (depth ) field in the image dataset ???

If yes , then we can separate that data and do the reconstruction (I hope)

Yes i have the depth image and i can display it in matlab, but we need to generate the point cloud to extract the x, y ,z coordinates of each point. If you have an other method to extract the x,y,z i will be thankful if you can tel me about it.

I meant in matlab : splitting the depth (x,y,z) coordinates from the image data and needs processing depending on the slice information in the image info /header field .

thank you very much for your answer i will check that, and if you get something about this topic tell me, and thank you for your time and help