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.

Email 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.

E-Mail confirmation

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.

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.

Option2: 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 for Munich’s academic network
• 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.

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.

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.

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.

Filter by date

This filter allows you to restrict search results to a specific time period.
• Start and End Date: Defines a range (e.g., 1500–1600).
• Single Date: Finds works from a specific year (e.g., 1525). Note: About 80% of records include date information, and 75% of those are available for filtering.

Filter by object

Some image databases store their data as objects. Objects link related images with their respective metadata. For object images, we save an object ID in order to retain this information. Using "Filter by objects", you can narrow down your search results to display only objects.
For example, if you search for “Kölner Dom”, the results list may include additional views under individual images, such as Gerhard Richter’s “South Transept Window” in “ConedaKOR Frankfurt, Goethe University Frankfurt am Main, Institute of Art History”. If you now perform the same search for “Kölner Dom” with "Filter by objects" enabled, only objects will appear in the 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.

Similar images

An image similarity search was integrated using image vectors that were created on the basis of the self-supervised learning algorithm SwAV (Swapping Assignments between Views). The algorithm is described in Caron et al. [1], an implementation is provided by Facebook [2]. A SwAV model [3] pre-trained with the ImageNet data set [4] was used as a model. Resulting image vectors, which are shortened to 80 dimensions sufficient for the result, were precalculated for all images in the image archive and saved in the index. The search engine queries are reduced to calculating the distance between the vectors stored in the index. The smallest distance is calculated using the Euclidean distance.

References:

1. Mathilde Caron and Ishan Misra and Julien Mairal and Priya Goyal and Piotr Bojanowski and Armand Joulin (2020). Unsupervised Learning of Visual Features by Contrasting Cluster Assignments. CoRR, abs/2006.09882.
2. https://github.com/facebookresearch/swav
3. https://pl-bolts-weights.s3.us-east-2.amazonaws.com/swav/swavimagenet/swavimagenet.pth.tar
4. https://www.image-net.org/

Under the Image Rights link in the footer, you will find general guidelines on image rights and publication in prometheus. In each record’s metadata, information on the rights to the work and rights to the photograph is included where available.
Next to each image, you will find the following button: This button provides specific publication information for the respective image, if available. In some cases, you can directly request publication approval from the rights holder.
See also: Terms of Use, Imprint, Privacy Policy

Creating a new collection

1. Select Images: Mark images in the results list by clicking the checkbox next to each image. Alternatively, click "Select All" to choose all displayed images on a page.
2. Create a Collection: Click "Save images to..." and select "New Image Collection".
3. Enter Details: Give your collection a title, add a description and keywords, and set access permissions.

Example:

• Title: Donatello
• Description: Seminar on Renaissance Sculpture
• Keywords: Florence, David, Bronze, 1386–1466
Tagging collections allows for thematic organization.

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.

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.

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

1. Select Image: Click „New Upload“ in the submenu and use the „Browse“ button to choose a file from your computer, camera, or USB drive.
2. Fill in Required Fields: Enter the title of the depicted work and specify the rights associated with the object.
3. Apply Metadata: Check the box "Apply metadata from the last record" to autofill certain fields.
4. Save and Edit: After saving, you can add additional metadata such as artist, location, or iconography.
Note: Clicking the information button next to each field provides additional details.

Image Rights

Differentiation between rights to the artwork and rights to the reproduction:

• Reproduction: Name the photographer or, if unknown, cite the source (e.g., book title). You may also specify a CC license for reuse.
• Artwork: Provide the name of the creator. Copyright remains with the artist or their heirs for 70 years after their death, after which the work becomes public domain.
Note: At least one reproduction rights statement is required.

Parent Object

You can link your uploaded image to a „parent object“. For example, you can define a photo of Cologne Cathedral as the parent object and then associate additional photographs—such as those of the nave or the west façade—with it.

Display of Uploaded Images

You can link your uploaded image to a "parent object". For example, you can link a photo of Cologne Cathedral to its corresponding parent object. Under "My Database", all your uploads are listed. You can:
• Adjust the view: switch between gallery view and list view.
• Define the sorting: sort the list by criteria such as artist, title, or location.
• Perform a search: filter your uploads using specific search criteria.
• Edit images: Use the checkbox next to each image to select one or several images for editing. Note that any changes to metadata will be applied to all selected images.
• Delete images: Use the trash can icon to remove images from your database.
• Check approval status: The traffic light icon indicates whether the image has been approved by the prometheus office. Only after approval can images be used in public or shared image collections and presentations.

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.

Management of Your 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

Accounts in the prometheus image archive have different permission levels:
• User o Log in with your username and password from any computer o Search the databases o Use advanced features such as creating your own image collections and presentations
• Administrator o Manage personal accounts within your institution o Further details: see “Administration guidelines”
• Database Administrator o Edit information related to your own database o View image ratings for relevant datasets o Further details: see “Information for image providers”

Administration Management

As an administrator, you can create and manage personal accounts for members of your institution. These functions are available under the menu item “Administration”.

Creating a Personal Account

In the submenu, click the button “Create a new account”. A form will open. Mandatory fields are highlighted in orange.

Mandatory fields:

• Username (e.g., j.doe)
• Email address (e.g., j.doe@example.com)
• Password (minimum 8 characters)
• Confirm password
• First name
• Last name Optional fields: Title, address, postal code, city, local identifier, notes. If the person wishes to subscribe to the newsletter, tick the corresponding checkbox. The account will be assigned to your institution automatically.

Setting the Validity Period

By default, personal accounts are valid for one year. Alternatively, you can choose a validity period of 6 months, 1 year, 2 years, or 3 years.

Examples:

• 6 months for exchange students who stay only for one semester
• 2–3 years for first-year students who will remain at the institution longer Guest accounts are also available if needed; these are valid for only one month and can later be deleted or converted into regular accounts. Once all information has been entered, click “Save” to create the account.

Account Expiration

To prevent former members from continuing to use the service, all accounts expire automatically. Only current members of your institution can use the license. Four weeks before expiration, users receive an email asking them to contact their administrator for an extension. After the expiration date, access is automatically deactivated. You can reactivate an expired account at any time by selecting a new validity period.

Account Overview

In the submenu, you can display accounts in the following categories:
• All accounts
• Active accounts
• Pending accounts
• Expired accounts
• Guest accounts Use the search box above the list to search by username, email address, first name, or last name.

Editing Accounts

Clicking on a username opens the stored data. Here you can:
• Edit data
• Reactivate accounts
• Delete accounts
• Export user data as a PDF file These editing functions are also available directly next to each username in the list.

Using the Archive Without a Personal Account

Administrators can also use the image archive without creating a personal account for themselves by assigning the role “User” in their own profile. After logging in with your username or email address, you can use the archive as a regular user and also create accounts as an administrator.

What Does “N.N.” Mean?

When “N.N.” appears instead of a name, it means that:
• The person is no longer a member of the prometheus image archive, or
• You are not allowed to view their name due to privacy reasons.

De-registration as Administrator

If you wish to terminate your administrator rights, please inform our office by email (info@prometheus-bildarchiv.de). At the same time, the new administrator must send their application form to our office. Your account will remain active, but your administrator rights will be removed.

Settings

Below your general profile information, you will find the “Settings” section of your prometheus account. In this area, you can define personal preferences for various features:
• Access
• Search
• Image display in the results list
• Image collections
• Presentations
• Uploads
Click on the arrow icon next to each section to expand or collapse the category for viewing and editing. Within each section, you can use dropdown menus to select and save your preferences, such as your preferred start page after login, the number of images displayed in the results list, or the sorting criteria for images in your collections.

Inactive Users

If a user is inactive or deleted, their profile will no longer be accessible. To protect privacy, no public information will remain available.