This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Fotowkibalancecontrast. Characteristic curves for contrastdebalanced photomaterial Sample result of greyscale shot Own Sergej Qkowlew Photographic techniques
Page 2023 Free-images.com. All images are Public Domain