Defringe and 1:1 clickable preview

[tomczak]

Would it be a good idea to set Defringe preview to 1:1 clickable mode - in the same way as Chromatic Aberration and Sharpen are done? The reason is that 1:1 preview is pretty much the only way to adjust the parameters, and one has to move around the picture in 1:1 to do it well.

p.s. The new preview button in CA is awesome!

[tomczak]

Also with Defringe, could I be explained how the Threshold actually works: would it look at all the pixels in the image, find the pixels that are brighter (HSV-V?) than the set threshold, then look for pixels within the set radius from each of the 'bright subset' from previous pass, and if they are within the set hue range, desaturate them?

The reason I'm asking is that I experimented with it on a typical fringed image of tree branches against blue sky and I'm able to desaturate large patches of sky with it, which means to me that there is no edge detection logic there, is it? I haven't done it yet, but would it make sense to try to limit defringing to the edges with a mask, or would it be counterproductive?

[jsachs]

Yes, that is how it works - it looks for pixels of the right hue that are brighter than the threshold. If you find you are desaturating sky, your hue range may extend too far toward cyan.

[tomczak]

The Radius in Defringe seems to be continuous, but the radius values displayed are integers: can the Radius actually take a fractional value?