Color Profiles¶
Standard RGB¶
sRGB is the default color space used when generating thumbnails. PhotoPrism and web browsers assume this color space for all pictures that do not have an embedded ICC color profile.
ICC Profiles¶
An ICC color profile for wide-gamut displays can optionally be embedded in image and video files. For color profiles other than sRGB and Display P3, the thumbnails must be generated with libvips by setting the PHOTOPRISM_THUMB_LIBRARY config option to vips or auto so that the ICC profiles are preserved:
| Environment | CLI Flag | Default | Description |
|---|---|---|---|
| PHOTOPRISM_THUMB_LIBRARY | --thumb-library | auto | image processing LIBRARY to be used for generating thumbnails (auto, imaging, vips) |
| PHOTOPRISM_THUMB_COLOR | --thumb-color | auto | standard color PROFILE for thumbnails (auto, preserve, srgb, none) |
Image colors may otherwise not be displayed correctly, which is particularly noticeable with ProPhoto RGB and Adobe RGB, as these cover a wide range of colors:
Color Detection¶
Color detection is performed while indexing using a 3x3 thumbnail that covers the top, bottom, and center of an image e.g. https://demo.photoprism.app/library/browse?color=green.