Re: 3d Reconstruction from Stack

Posted by dscho on Jul 06, 2011; 5:09pm
URL: http://imagej.273.s1.nabble.com/3d-Reconstruction-from-Stack-tp3684002p3684003.html

Hi Andrew,

On Thu, 23 Jun 2011, Andrew E. Meyer wrote:

> We have an application where we are taking a stack of pictures of a fuel
> injector seat and spray orifices, and trying to reconstruct a
> 3-Dimensional image for use in verifying that the hardware was made to
> spec.  We are using a microscope with a short focal length, so that the
> features in the stack appear to grow in size as we get closer to the
> object.  (think of a star field animation, where the nearer stars go
> racing to the edge of the picture as the spaceship goes through the star
> field).
>
> First, is there a name for this "star field" effect by which I could
> search for information?
>
> We have tried using stack focuser and EDF to create a three dimensional
> map from our stack with very limited success-the images are very noisy
> and don't correspond to the reality which we can measure, so we cannot
> trust them for the stuff we cannot measure.  Maybe I'm just not using
> these extensions properly?  I'm new to this, but it is my understanding
> that these techniques determine position of each point based on how
> sharp the focus for the point is, so moving features might be a problem
> for them.

I imagine the problem is that your stack slices are not really in and out
of focus.

So maybe you need something completely different: you could use SIFT
features in every slice to generate robust landmarks, and then use a
RANSAC to find the most likely 3D locations of the landmarks.

The last step would be an inverse mapping from the recorded stack into a
3D height-field.

Ciao,
Johannes