Hot pixel correction as part of watermarking?

My camera's images get pretty noisy when the exposures are long, and there's one stuck pixel that just destroys dark images. Pixelzap can fix this, but it's Windows-only. I'm guessing the watermarking tool could probably perform darkfield subtractions.

I was unable to find a Linux-based tool that does this, but if there's one out there, has anyone considered integrating it with Gallery? If such a thing doesn't exist yet, I'll ask the author of Pixelzap if he'd consider opening the source for the command-line version.

My main reason for wanting it as part of the watermark routine is to minimize JPEG generation loss. I usually upload images exactly as they came out of the camera. Thoughts?