Portrait sample: photograph of astronaut Eileen Collins, courtesy of NASA. Public domain; no known copyright restrictions. Used as a technical photo-editing demonstration, without implying affiliation or endorsement.

Source: scikit-image v0.19.3 data/astronaut.png
https://github.com/scikit-image/scikit-image/blob/v0.19.3/skimage/data/astronaut.png
Source provenance and rights statement: https://github.com/scikit-image/scikit-image/blob/v0.19.3/skimage/data/_fetchers.py (astronaut function)
Original NASA Great Images source: https://flic.kr/p/r9qvLn
SHA-256: 88431cd9653ccd539741b555fb0a46b61558b301d4110412b5bc28b5e3ea6cb5