how to get the depthmap of the dataset Make3d?

Question

1) Train400Depth.tgz Laser Range data with Ray Position Data Format: Position3DGrid (55x305x4) Position3DGrid(:,:,1) is Vertical axis in meters (Y) Position3DGrid(:,:,2) is Horizontal axis in meters (X) Position3DGrid(:,:,3) is Projective Depths in meters (Z) Position3DGrid(:,:,4) is Depths in meters (d)

2) Train400Img.tar.gz Images all in resolution 2272x1704

http://ai.stanford.edu/~asaxena/learningdepth/data.html