Can you use MATLAB for 3D Image Processing?

I'm familiar with 2D feature extraction using the object analysis functions in the image processing toolbox. With this I can identify various features and extract its 2D co-ordinates.

But how can I extend this idea to 3D? How can I identify an object and return its 3D co-ordinates? I'm open to any idea, and I have no constraints on physical modifications needed to make on the object to be identified. E.g, paint it green, add a sticker with concentric circles etc. I also do not mind if it only works when the object is within a specific range of distances from the camera. As long as I can get a 3D coordinate from a desired object in a 3D image.

I am using a kinect for windows camera, and I also have the Simulink Support for Kinect Library, which among other things returns a real color point cloud from the Kinect.

Thanks!

Answer 1

[David Young]

It may be useful to look at the Computer Vision System Toolbox, which goes beyond the Image Processing Toolbox, and which includes stereo calibration and 3-D reconstruction.

But note that if you have a 3-D array already, many of the IPT functions such as regionprops will work. For many operations the extension from 2-D to 3-D is straightforward - if you are having trouble with a specific operation it might be worth saying more about it as it's probably easier to discuss a particular process rather than the very general question you've posed.

[Craig]

Thanks for your answer. I do have a 3D image already, I have it as a depth image, or by using "depthToPointCloud" I get a point cloud. Do I need to convert into another format before using regionprops ?

Secondly, my 3D point cloud is a 640x480x3 matrix. How can I convert this into a simple matrix of [x,y,z] co-ordinates so I can use it with the clickA3Dpoint function, shown here.

This function takes arguments in the form:

[ 1,   1,   1  ;
  1.5, 1.5, 1.5;
  2,   2,   2  ]

And will return a point cloud with 3 points, at (1,1,1), (1.5,1.5,1.5) and (2,2,2). How can I convert my 640x480x3 point cloud matrix into this form?

[D.Jaisil Rose]

Is the third coordinate(z) of your image is color planes(RGB)?or Is it the image depth?