Cloud Mask
imageryprocessing
Per-pixel indication of cloud presence in an optical scene. Three sources
of truth differ subtly: s2cloudless is a single-class probability that is
thresholded into a binary mask; the Sentinel-2 SCL gives discrete classes
including thin cirrus (10) and cloud-shadow (3); Landsat Collection 2
CMASK / Fmask packs cloud, cloud-shadow, and cirrus into separate bits of
QA_PIXEL. Folia's canonical class codes for an interoperable cloud-mask:
| code | class |
|------|-------|
| 0 | Clear |
| 1 | Cloud |
| 2 | Cirrus (thin / high) |
| 3 | Cloud shadow |
Recipes that only need a binary clear/cloud distinction collapse codes
1-3 to "not clear". Consumed by every optical reflectance, index, and
composite op.
Canonical units:
categorical