
prometheus is a distributed digital image archive that currently makes more than 3,496,000 images of over 120 databases from institutes, research facilities and museums researchable on a common user interface.
Situated at the Institute of Art History of the University of Cologne, prometheus is supported by the non-profit association prometheus e.V. which promotes the ongoing developments of the digital media for science and research.
Image series of the week

News
If you search for “spring” in the simple search, Prometheus will display nearly 4,500 records, which you can sort and then display by date. If you search for “spring” in the title in the advanced search, fewer results come up, and you can now filter these by date.
If you enter the period from 1900 to 2025, you will see 293 data records. These include images with “1870–1994,” “around 1895,” “ca. 1895–1900,” “first quarter of the 20th century,” and years from “1900” to “2016.”
What’s behind it?
The dating of each image from the 128 heterogeneous image databases currently integrated into Prometheus is specified in the corresponding field.
These are read for the filter. A year such as 1972 or a specification such as “from 2005 to 2025” is unambiguous, but a specification such as “around” or “approx.” is not. It cannot be automatically read and must be translated in a way:
How many years does an approximate period represent? The beginning, middle, and end of a century, as well as the first and second half or first third to fourth quarter of the century, also require a definition first, see „Parse human historical datings and convert them to Julian day ranges“