Field guide
Denoise before upscaling
Upscaling increases the size of noise along with the subject. A restrained denoise pass can simplify the signal before interpolation or a learned model magnifies it.
01
Separate sensor noise from texture at one-to-one scale. Random coloured specks are good candidates; pores, fabric weave and distant foliage are not.
02
Use chroma reduction before strong luminance smoothing. Coloured noise is usually more distracting, and removing it preserves more perceived fine structure.
03
Preview the denoised source and the enlarged result. A source that looks slightly too smooth may become convincingly clean after scaling, while waxy regions remain waxy at every size.
04
Do not denoise block boundaries as if they were sensor grain. Messaging-app compression needs gentler deblocking, because broad smoothing can spread the blocks rather than remove them.