Photo denoise, measured
| Measured noise σ | Luminance opening | Colour opening |
|---|---|---|
| under 2 code values | 30 | 50 |
| 2–4 | 50 | 50 |
| over 4 | 70 | 50 |
What it will not do
It does not paint skin smooth or retouch faces, and it does not remove dust or scratches: those are damage, not noise.
Related on this site
- The argument for the order is written out in reduce noise first, then sharpen.
- For a clean file that only needs sharpening: the sharpener.
- To see the noise and sharpness figures of a file without changing it: check image sharpness.
Questions: denoise a photo
Why does noise come first?
Because sharpening a noisy picture turns grain into structure, and once it is structure no later pass can tell it from detail. Calming the noise first lets a light sharpen restore the edges without dragging the grain up with them.
What is the difference between luminance and colour noise?
Luminance noise is grain in brightness; colour noise is the red and green speckle a phone produces in low light. Colour noise is reduced on the colour difference planes only, so it cannot soften an edge; luminance noise is reduced with a guided filter whose strength follows the noise measured on your own file.
Will denoising remove detail?
Some. Fine texture and fine grain occupy the same scale. The Detail kept control decides how much of it the luminance pass leaves alone, and the readout prints noise and edge definition before and after so the trade is visible rather than hidden.
Is the photo uploaded?
No. Every pass runs in a worker in this tab.
