How to fill empty parts of a projected image?

When i projected a 3D model on a 2D plan (Perspective projection) the result of the projection appeared as the following image.

http://i.imgur.com/3dFdB.png

and i need to fill empty points in this image to look like this one

i wonder that i can find a good way to fill this points with a professional way using any image processing algorithms using matlab

http://i.imgur.com/JJac0.png

Answer 1

[Sean de Wolski]

CSSM:StevenLord_on_the_concave_hull

First, read this (the whole thread, but mainly Steven's pictorial example) so you know what kind of ill-posed problem you're up against.

I would think using the distance transform ( bwdist ) would be a good start. You could get the distance xform, threshold it and then erode the whole thing by a disk strel with a diameter (or radius?) the value of the threshold.

More!

You might also be able to do a delaunay triangulation and then only keep small area triangles.