I have some photos shot in low light with a compact camera which exhibit significant chroma noise, which I’d like to correct as much as possible.
My searches turned up a technique called “chroma blur,” where, presumably, one or more color channels can be blurred to smooth out chroma noise. Unfortunately, I can’t locate this at all in Aperture 3.
There is mention of this on Apple Support and an example of its use, but both seem to be for Aperture 1. This part of the RAW adjustments is not present in Aperture 3, nor does it turn up when I search the manual.
From what I read, the available options in the RAW Fine Tuning adjustment can vary based on the camera and RAW file format. However, chroma blur seems like something that wouldn’t be dependent on specific RAW features, or even RAW in general.
I have two other techniques I’ve been using for reducing chroma noise:
For splotchy noise, adjust the noisy channel’s luminance & saturation until it matches a surrounding area of flat color. Example:
Cycle of: Original RAW image data (100% crop); yellow channel saturation increased to show noise; corrected image.
For grainy noise on a flat-colored area, brush in a color adjustment which drops the noisy channel’s luminance. Example:
While these two techniques seem viable, they both involve much more by-hand correction than I’d like, and chroma blur seems to require less. Is chroma blur hidden in Aperture 3 somewhere? What other techniques should I try to reduce chroma noise?