Posted by
Michael Schmid on
URL: http://imagej.273.s1.nabble.com/Applying-calibrated-geometrical-distortion-to-an-image-tp5001968p5001973.html
Hi Alan,
hmm, it seems to me that bUnwarpJ should be able to do the same
undistortion for all of your photos:
Take a photo of a grid, and create a synthetic undistorted grid of the
same size.
With bUnwarpJ, use 'Save Transformation' to store the transformation
necessary to convert the photo into the synthetic grid.
Then, use 'Load Elastic Transformation' to apply it manually, or use the
macro interface to apply it to an image stored on disk.
Michael
__________________________________________________________________
On Sun, March 3, 2013 09:33, Alan Hewat wrote:
> I have a camera instrument with a fixed geometry that produces slightly
> distorted images.
>
> I want to determine the distortion correction field, by comparing the
> distorted image with the undistorted image, eg of a grid. I then want to
> apply that calibrated correction field to any image with the same camera,
> without user interaction. I need a precise automatic correction, since the
> user must measure positions within the corrected image.
>
> I tried
http://biocomp.cnb.csic.es/~iarganda/SplineDeformationGenerator/> which allows a choice of distortion models with a small number of
> parameters. This works, but calibration requires an a priori choice of the
> type of distortion (fisheye, barrel etc...) and then manual adjustment of
> the parameters to obtain what <b>appears</b> to be the least distorted
> image. It is too subjective, and difficult to obtain parameters that
> remove all distortion.
>
> Then
http://biocomp.cnb.csic.es/~iarganda/bUnwarpJ/ looked promising. This
> determines the distortion field that will transform between an
> un-distorted and distorted image pair. But again it appears to be a manual
> process and I couldn't see from the tutorial how I could store the
> distortion field and automatically apply it to new images with the same
> distortion.
>
> I would have thought that calibrated distortion correction was a common
> need for many fixed geometry cameras, but couldn't find much more on the
> WWW. Any suggestions would be welcome.
>
> Alan.
>
>
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