Access modes

One-Week Trial Access

This trial allows interested users to test prometheus free of charge for one week. Please specify your research interest, as the image archive may only be used for research and teaching purposes. After registration, you will receive an email to confirm your address. Your trial access will be activated after verification.

Access via Your Institution

If your university is part of the eduGAIN network, you can log in directly using your institutional credentials. Simply select your institution from the login form and follow the redirection process. After a successful login, you can either create a new prometheus account or link your existing account.

Alternatively, you can access the image archive through a licensed institution. To do this, select the option “Free access via your institution” in the registration form, complete your registration, and confirm your email address using the link sent to you. Afterwards, choose your institution from the list provided. To complete the process, submit a valid certificate of enrollment to the designated contact person to have your access activated for a longer period.

Individual License

If you do not have access through an institution, you may purchase an individual license for personal academic use. The license is valid for one year and does not renew automatically. Providing a research interest is also required in this case. After registration, you will receive a confirmation email and be redirected to the payment options.

If you choose to pay via PayPal, you will be redirected to the PayPal website to complete the payment, and your access will be automatically activated once the transaction is successful. If you prefer to pay by invoice, please provide your billing address. The office will process your request and send you the invoice along with the confirmation of your activated access via email.

E-Mail confirmation

After registration, you will receive an email with a confirmation link. Click the link to verify your email address and complete the registration process.

If you missed the confirmation of your email address and the link of the automatic email is already invalid or you didn't receive any verification email because you might have made a mistake e.g. by mispelling your email address, you can always get a new verification mail. Just log yourself in with your username and password at our homepage www.prometheus-bildarchiv.de. Your registered email address will be displayed again. Here you can, if necessary, correct any spelling mistakes and click on 'Proceed'. Did you know? If you don't have a personal account yet, you can sign up for one for free! Just select your institution on the signup form and benefit from the advantages of a personal account such as image collections and presentations. You also won't have to accept the terms of use each time you log into the image archive.

Login

Personal account

Enter your login name or email address along with your password. Press Enter or click the login button.

Password forgotten?

If you forgot your password, enter your login name or email address and click "Forgot Password?". You will receive an email with a link to reset your password.

Free access via your institution

Option 1: eduGAIN (recommended)
If your institution is listed under "eduGAIN Login" on the prometheus login page, you might be able to use your institution's login server to authenticate for our image archive. To do so, please select your institution from the dropdown menu.

You will then be redirected to a login form on the institution's website and after signing in with them, you should be redirected to the prometheus image archive.
Once you are back, we need to create an account for you with us. If you already have one, you can link it with the account at your institution but you can just as easily create a new account with us. Select the option that is appropriate for your situation and follow the on-screen instructions:

Done! Whenever you login via your institution from now on, you will be redirected to our image archive right away.

Option 2: Campus Login
If you are within the registered IP range of a licensed institution, you can use campus access. Click "Campus Access," read and accept the terms of use, then press Enter or click the login button.

After successful login, you can navigate the image archive via the menu bar. Your login status appears in the top right corner, where you can also log out.

Issues with Campus Access?
Ensure that you are within the campus network of a licensed institution. Specific IP addresses must be registered with prometheus for campus access.
To analyze the issue, visit the "IP Address Information" page and include its output in your support request.

VPN Connection
If using a VPN, ensure that "Full-Tunneling" is enabled and "Split-Tunneling" is disabled to access external websites such as the prometheus image archive. More details can be found in your IT department's documentation.

Helpful Resources:

• Full- / Split-Tunnel – Explanation by the University of Cologne's Regional Computing Center
• What is split tunneling? – Explanation and deactivation guide from the Munich Scientific Network (LRZ)
• Split tunneling – Technical details on Wikipedia

Simple search

Use the simple search to quickly and easily search across all fields.

Advanced search

The advanced search allows you to refine your query by linking different categories with Boolean operators. By default, four search fields are available, but more can be added using the "+" button.

Available Categories

• All
• All incl. ARTigo Tags
• Artist
• Title
• Location
• Findspot
• Genre
• Material
• Keyword
• Description
• Dating
• Image Credit
• Image Rights (Work)
• Image Rights (Photography)
• Record
• Object
• Average Rating
• Number of Ratings
• Comments

Boolean Operators

• AND
• OR
• NOT

Linking examples

• Artist: Da Vinci AND NOT Title: Mona Lisa → Displays all works by Da Vinci except the Mona Lisa.
• Artist: Michelangelo AND Location: Rome AND NOT Title: Sistine Chapel → Displays all works by Michelangelo in Rome except the Sistine Chapel.

Wildcard Search

Use the asterisk (*) to include different word endings. Example: "Sun" finds "Sun," "Sunflower," or "Sunset."

Database selection

prometheus offers a wide range of different databases. You can limit your search to specific areas, such as the field of archaeology or museum databases only. To make selection easier, the databases can be sorted by title, location, type, or description.

Query syntax

In the Advanced Search you can use a specific query syntax to refine your search. For more details, see the full documentation on the Elasticsearch query syntax . The Wikipedia article on Levenshtein distance provides additional information about the similarity measure used in fuzzy search.

Boolean operators

Combine search terms using the following operators:

• AND → Both terms must be present.
• OR → At least one term must be present.
• NOT → The first term must be present, but the second must be excluded.

Examples:

• artist = Picasso AND title = Bull → Finds all images of bulls by Picasso.
• artist = Picasso AND NOT title = Bull → Finds all works by Picasso except bull images.
• artist = Picasso OR title = Bull → Finds all works by Picasso as well as all images titled "Bull," regardless of the artist.

Note: Operator precedence is OR > NOT > AND.

Wildcard Search: * and ?

Use wildcards to replace parts of a word:

• * represents any number of characters (including none).
• ? replaces exactly one character.

Examples:

• Vin?ent van Gogh finds both "Vincent van Gogh" and "Vinent van Gogh".
• Sun* finds "Sun," "Sunday," "Sundown," etc.
• *light finds "flight," "redlight," etc.

Fuzzy search: ~

Add a tilde ~ at the end of a word to find similar terms. Example: **Gaugin** finds "Gauguin," "Gaudin," "Baudin," etc.

Phrase Search: "..."

It is possible to do a phrase search by putting the terms in "...". That way the exact order of the terms will be taken into account. A query for "paul baum" would return all records on the artist Paul Baum. While a query for paul baum (without quotation marks) would find both terms regardless of order. E.g., it would also find Paul Klee, Baum im Garten.

Boosting

Use the caret symbol (^) followed by a number to give certain search terms a higher priority. Example: gold OR silver^5 gives "silver" a higher relevance than "gold".

Search results

List of Results

Above the results list, you will find the search form with your current search query and the selected databases. You can refine or modify your search here.

You can sort results by:

• Relevance
• Artist
• Title
• Location
• Image Credit
• Database

Results can be displayed in two formats:

• List View: Displays metadata for each image.
• Gallery View: Displays image thumbnails.

You can also set how many records appear per page and navigate between result pages using the dropdown menu.

Directly from the results list, you can:

• Select images for an image collection: Use checkboxes to select images.
• Save images to a collection: Add images to an image collection, presentation, or favorites bar.
• View full record: Displays detailed metadata.
• Enlarge image: Provides a second zoom level, suitable for saving.
• Download image: Saves the image and metadata.
• External link: Opens the corresponding image in the source database.
• Image rights and publication: Displays licensing and usage details.

Direct Search for Artists
Clicking on an artist's name in the "Artist" field will automatically start a new search for that person.

Creating Image Collections
You can save selected images in collections. For detailed instructions, visit Image Collections.

Creating image collections is only possible with a personal account.

Creating a New Image Collection

1. Add individual images: Next to each image in the results list, you’ll find a button that lets you add this image directly to a new or existing image collection.
2. Select multiple images: To add multiple images at once, use the checkboxes next to each image. Then click the three-dot menu above the results list and select “Add records to image collection”.
3. Create a new collection: In the dialog that opens, select “New image collection”.
4. Enter details: Give your collection a title, add a description and keywords, and define the access permissions.

Example

• Title: Donatello
• Description: Seminar on Renaissance Sculpture
• Keywords: Florence, David, Bronze, 1386–1466

Tagging your image collections allows for thematic organization.

Working with collections

• Sorting: You can sort the contents of the image collection by artist, title, location, image credit, or database.
• View: Switch between gallery view (thumbnails) and list view (basic metadata).
• Remove image: Use the trash bin icon to remove an image from the collection.

Adding images to existing colletions

1. Select Images: Mark images in the results list.
2. Choose a Collection: Click "Save images to..." and select an existing collection.

Note: Selection applies only to the current page. Save your images before navigating to a different page.

Managing image collections

In the submenu, the following options are available:

• My Collections: List of your personal image collections.
• Shared Collections: Collections available to you for viewing or collaboration.
• Public Collections: All publicly accessible image collections.
• Create New Collection: Create an additional collection.

Shared collections

• Edit Access: You can modify content but not change the title or access rights.
• View-Only Access: You can view, copy, and download the collection but cannot edit it. For edit permissions, contact the owner.

Note: Copies of shared collections are private by default.

New Upload

To upload a new image, click on “My Uploads” in the main menu. This will open your personal upload overview. Then click the plus icon in the upper right corner to start a new upload.

Alternatively, you can click on “Reuse metadata” in an existing record. This will create a new upload using the already entered metadata, which you can adjust if needed. This function is particularly useful for related images or series.

First, select an image file from your local device. Then fill in the required fields: these include the title of the depicted work and the information about image rights. Click “Save” to proceed.

In the next step, you can add more metadata to your upload. After saving, you can edit the dataset at any time and add further information such as the artist, location, or iconography.

Tip: The info button next to each input field provides additional guidance on how to fill it in correctly.

You can add individual images or entire image collections to your favorites. To do so, simply select the corresponding icon within the respective entry.

You can access your list of favorites via the same icon in the main menu. There, you can browse your favorites or filter them by individual entries or image collections.

Personal Account

You can change your personal login details at any time by clicking on your name in the top right corner.

The following changes are possible

• Login name, password, and email address (mandatory fields are outlined in orange)
• Address (you can update this yourself without notifying the office)
• Newsletter subscription (subscribe or unsubscribe at any time)
• Profile text (displayed on your profile page)

Your access is time-limited and managed by the administration of your institution. Four weeks before your account expires, you will receive an email notification. If you need an extension, please contact your institution’s administrator.

Roles

Access to the prometheus image archive is granted with different permission levels:

• User
  • Login with username and password from any computer
  • Search within the image databases
  • Advanced features such as creating personal image collections and presentations
• Administrator
  • Managing individual user accounts at their own institution
  • More information: Guidelines for Administrators
• Database Administrator
  • Editing metadata related to their own database
  • Viewing image ratings for corresponding records
  • More information: Information for Contributing Institutions

Settings

Below the general profile section, you will find the Settings of your prometheus account. In this area, you can customize default options for various functional sections:

• Access
• Search
• Image collections
• Uploads

Within each section, you can use the dropdown menus to select and save options such as your preferred start page after login, the number of images displayed in the search results, or the sorting criteria for the images in your collections.

Note: The Settings menu within your personal account has been moved to a different location. You can now access it via your profile: https://prometheus.uni-koeln.de/en/profile.

Fullscreen viewer

With the fullscreen viewer, you can explore the image in more detail:

• The back button returns you to the previous page.
• Use the zoom slider or your scroll wheel to zoom in and out.
• Click and drag to move the image.
• A click on the image hides the controls; another click shows them again.

Similar images

A method for finding visually similar images has been integrated using image vectors generated by the self-supervised learning algorithm SwAV (Swapping Assignments between Views). The implementation was provided by Facebook, and a pretrained model based on the ImageNet dataset was used (ImageNet).

The resulting vectors were reduced to 80 dimensions, precomputed for all images in the archive, and stored in an index. Search queries then compare these vectors using the Euclidean distance – returning images that are most visually similar.

Under the Image Rights link in the footer, you will find general information on image rights and publication options in prometheus. The metadata of each record includes, where available, information on the rights to the work and the rights to the photograph of the respective image.

Via the three-dot menu to the right of each image, you will find individual details on the publication of that image under Image Rights and Publication Information, provided they are available to prometheus.