[Insight-users] Geospatial registration

[Garrett Potts]

Hello Luis:

I am currently testing the registration on a CIB (controlled image 
block) and a Landsat pan band.  Eventually I would like to do cross 
sensor registration and eventually batched bundle adjustments.  I have 
a 5 meter and a 10 meter CIB file and the landsat completely overlaps 
the CIB data set.  I currently just hand picked a point that looks like 
it should correlate good.  The Landsat models are around a few pixels 
off.  Within our software we have parameters that can be tweaked in 
order to adjust and remove the errors.  I figured this would be nice to 
bridge since Insight package works well with adjustable parameters.

Currently I have the following:

1.  Derived a transform class that bridges to our adjustable 
parameters.  Since I can't calculate the partials explicitly I 
numerically calculate it by varying the adjustable a small amount and 
see how x and y change and set the Jacobian.  I am not sure what the 
ideal perturbation of each parameter should be to calculate an accurate 
partial.

Every time the SetParameter is called I adjust our internal transform 
found in our internal image processing chain.

2.  Derived an interpolator.  Just returns a pixel value in the 
floating image chain.

Note:  Both images are resampled and projected to a Map view and all 
analysis is done there.  Given that, I currently don't transform any 
points coming into the transform.


> You may want to look closer at the size and location of the
> image regions that you want to be taken into account while
> the image metric is computed.  In particular that will
> affect your selection of the FixedImageRegion() and eventually
> the use of an Image Mask.

I have no clew what the best dimension is to analyze and am not sure 
what metric works best.  Currently, I think the Mutual information 
metric is working well.  I am still having problems with parameter 
adjustments and getting the parameters to settle down to an accurate 
adjustment.

Any suggestions on good metrics and size of the image to analyze let me 
know.


Ultimately I would like to automatically find the correlation points on 
the image and then take the minimal fit of all points and use the 
result as the final adjustment.


Thank you for the help and

Take care


Garrett