Is Defringe supposed to have an effect when equalizer is zeroed out?

I was editing an image, and realized that the Defringe tool seemed to apply a noise filter when turned on, but when the equalizer was zeroed out. Notice the smoothing in the petal where the highlights were recovered.
There are a lot of other functions applied to in this image, so it is likely the interaction of one/some of them. I assume its a bug, but wanted confirmation before submitting a bug report.

DSCF7795.RAF (21.7 MB)

DSCF7795-1.jpg.out.pp3 (23.9 KB)

Image may be used for the purpose testing and troubleshooting of RawTherapee.

Just had a look: Something else is going on here; Turning on defringe creates the fringe. There’s no fringing to begin with.

If I turn the module on and zero out all colour channels, or set the radius to 0, the fringe is gone as well.

I’ve seen this behaviour (a fringe being created by turning on the module) once or twice before. Might be a result of the contrast between 2 contrasting areas and the slider settings.

I guess that turning off the module is the sane thing to do. Not sure if this is a bug or one of those one-in-a-million scenarios that can’t be helped.

Its more than just fringe. It loose like it’s applying a median filter.

It seems to be caused by an interaction with the CIECAM tool.

I.e., turn off the CIECAM tool and the problem vanishes.

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Nailed it. If you load a neutral profile and just enable the default CIECAM tool it happens.

So is this a reportable bug?

I think so.

But I’m afraid it won’t be easy to fix, most probably because of the differences in how color is interpreted in CIECAM and in Defringe. I bet the defringing process doesn’t take into account the changes made by CIECAM and does things it’s own way.

But at least it will be on record.

Edit: bug report filed

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Based on the toolchain Defringe is processed before CIECAM