Chromatic Aberration causes said aberration on edges

[andrewh]

When I use the chromatic aberration widget to do a small neagtive red shift, it works beautifully on my photo but sadly adds a cyan border to the left and top of my image. It is easy to get rid of by cropping but I am sure it is an unintended side effect of the transformation.

Hopefully you can see it in this small image.


Andrew from Addis

[jsachs]

This transformation works by applying different magnification factors to the R, G and B channels of a color image. Near the edges, depending on the offset values, there may be pixels for which data for some colors in unavailable since it refers to values outside of the original image, thus causing a color fringe at the edge. This could be removed automatically by cropping but this would change the image size and invalidate things like masks that require and exact size match.

[andrewh]

Thanks Jonathan,

I guessed it was part of teh transformation. Best to leave it until all is finsihed then crop - no problem.

Andrew