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Every week the top image bar on the homepage of prometheus changes and gives a first visual impression of the image series of the week. The topics are mostly inspired by current exhibitions, for example this week’s „Anna Oppermann. A Retro Perspective“ in the Bundeskunsthalle in Bonn. We often take an aspect of the exhibition or the artist’s work, such as Anna Oppermann’s “Ensembles” in this case, and look for suitable images in the prometheus image archive. We cannot always rely on a research database and 2,191 data sets on the artist’s work.
However, there is always a public image collection at prometheus that you can click on directly (see Fig. “1.”) and where you can find more material on the topic. As of today, you can also click on the thumbnails directly (see Fig. “2.”) and the associated data record will be displayed in the image archive.

We would be happy to accept your topics for a #pictureSeriesOfTheWeek, for an exhibition, but also for projects or campaigns. Get in touch with us and see how it can be implemented.

This year we will once again begin our information section in the picture archive with a look at the annual list of the artists you most frequently searched for last year.
Paula Modersohn-Becker made it to the top in 2022 but this year she came in 9th place.
She was replaced at the top by Pablo Picasso, followed by Vincent van Gogh and Max Ernst. The most wanted artist in 2023 is Hannah Höch behind this trio. With her there are seven other artists in the top 20.

All top 20 in 2023:

1. Pablo Picasso
2. Vincent van Gogh
3. Max Ernst
4. Hannah Höch
5. René Magritte
6. Claude Monet
7. Gabriele Münter
8. Caspar David Friedrich
9. Paula Modersohn-Becker
10. Hilma af Klint
11. Caravaggio
12. Albrecht Dürer
13. Otto Dix
14. Frida Kahlo
15. Nan Goldin
16. Henri Matisse
17. Gerhard Richter
18. Kandinsky
19. Rebecca Horn
20. Cindy Sherman

A lot has also changed in the list of the ten living artists who aroused the most interest on Google and which internet service providers identified for Monopol magazine compared to last year. Last year’s number 1 Banksy is no longer in the top 10, just like Jeff Koons, Cindy Sherman, Damien Hirst and Wolfgang Tillmanns.

1. Gerhard Richter
2. Yoko Ono
3. Marina Abramović
4. Anselm Kiefer
5. Leon Löwentraut
6. David Hockney
7. Yayoi Kusama
8. Isa Genzken
9. Kaws
10. Georg Baselitz

Images in prometheus are always displayed within a set size frame in the first and second magnification levels. Portrait or landscape format can be seen there, but how big is the image in reality?

The “size” field provides information about the dimensions of the original.
In our example it is 29.6 × 23.6 cm.

In order to get a visual idea of how big or how small the object is directly from the image in prometheus, the comparison size is integrated into the image archive as a 175 cm tall group of people. It is visible in all images where height and width are specified.

Around 75% of all data sets in the 124 image databases integrated in prometheus are dated and available for filtering search results by dating.
For example, if you search for “Christmas” in the advanced search, you will get 809 records in the results list.

Are you more interested in depictions of Christmas at a specific time? For example, around 1920? Under “filter by dating”, limit the results from 1920 to 1920. You will receive 30 data sets with the exact time “1920” and with time periods such as “around 1915 or “1876 – 1924” or “20th c.”.

Want another time period instead? Maybe 100 to 1.000 A.D.?

For about two years now, there is an image similiarity search in prometheus that allows you to find similar images within the image inventory based on one image.
It was developed and integrated within Task Area 3 of the NFDI4Culture project by Francisco Mondaca and Jörg Koch.
On the basis of the self-supervised learning algorithm SwAV (Swapping Assignments between Views), image vectors were created that are pre-calculated for all images in the image archive and stored in the index so the search engine’s queries is reduced to calculating the distance between these vectors stored in the index. For all new images in prometheus, additional image vectors are created at regular intervals (started just recently) and stored in the index.

You will find four similar images under the single image view.

By clicking on „Show all“ you can access the view of all similar images of the winter landscape we selected.

Wikidata is a free, shared database and a project of the Wikimedia Foundation with the goal of centralizing structured data and making it usable.
Last year we first integrated Wikidata search links into prometheus and a few months later the possibility to add the associated Wikidata ID to each image in the artist fields.

By clicking on “Add Wikidata ID” a window opens in which first the name can be entered and then the corresponding Wikidata entry can be selected. After saving, the Wikidata ID is added. If necessary, a click on the pen also enables correction.

These Wikidata IDs, the existing ones and the created ones, take you directly from the image archive to the corresponding authority data in Wikidata. And you can search for the Wikidata IDs in prometheus.

So far, 150 entries have been added this way. But there should be more to come in the next few weeks and months. Try it out, too!

Another image database is integrated into prometheus with the institute database “Historical Photo Collection“ of the Institute for Art and Visual History at the Humboldt University Berlin.

Most of the approximately 1,500 older photographs in the institute’s photographic collection that exist today were acquired antiquarian around 1950. Some of them date back to the early days of photography. Currently, around two thirds of the older photographs have been digitally indexed and the first 758 data sets are available for your research in the image archive.

If you have a personal prometheus account and want to use a new email address or have moved to another licensed institution, you can adjust your profile yourself.

Your profile will open and you will see your name, email address, … Another click on the pencil and you can change these details. Just like this, you can also change your institution or license there to continue to access your content such as image collections, your own database and favorites after the change.

Click on “License” – “Purchase a new license or change your institution …”.

In the list of licensed institutions you can see if your (new) institution belongs to it. If yes, select it, save and you belong to the new institution. Your administrator can find you in the list of the institution from now on and, for example, renew your access there if necessary.
In case your personal access has currently expired, it may still be possible to reactivate it with all personal settings. Please ask us before you have to create a new account and repeat your work in the image archive. We are happy to help.

In the final part of our short series on the survey results, we look at the responses to the question “What topics and content are you missing within the integrated image assets?” that we have summarized, as well as the overall rating.

35 out of 80 did not provide information on missing topics or content. Most of the 43.75% are not missing anything. They are satisfied with the range of topics.
What is missing for the other survey participants is primarily contemporary art.
12.5% mention the gap either in general terms or with specific examples of artists, genres or regions. Another 12.5% cite missing and incorrect metadata in their responses, as well as a lack of specific additional keywording (e.g., era, gender studies). Lesser-known artworks and the works of lesser-known artists* were also frequently mentioned as desiderata, by 7.5%, as frequently as “architecture.”
Other topics and contents mentioned: Photography (3), Middle Ages (3), Performance, Action Art (3), Videos (2), Art Worldwide (2), Ancient Cultures (1), Ethnographic Representations of Modern Costume (1), Decorative Arts and Furniture (1), Theater History, Performance History (1).

In our research for further image databases that we can integrate into prometheus, we will consider the mentioned topics and contents and search specifically. If you have concrete hints, please do not hesitate to let us know.
We would also like to draw your attention to the upload option, where you can, for example, insert your own images from research trips and release your images from your own image database to everyone in the image archive, if they have been approved by the prometheus office after editorial review in the sense of quality assurance.

At the end of the questionnaire, we asked you how likely it is you would recommend the Image Archive to a colleague or friend and survey participants distributed the following stars:

10 stars: 37,50%
9 stars: 16,25%
8 stars: 15,00%
7 stars: 8,75%
6 stars: 6,25%
5 stars: 7,50%
4 stars: 3,75%
3 stars: 2,50%
2 stars: 1,25%
1 star: 1,25%

So we still have some work to do and will keep you up to date on the next steps and results.

The second part of the evaluation of our survey focuses on “image quality”. Regarding the question “How do you rate the quality of the images, the quality of the digital copies (resolution)” on the scale “very good – good – usable – rather bad – very bad – no answer” we received the following answers:

We rougly clustered comments we have received on the topic:
„image quality“
- You can often find images with better image quality when searching Google images.
„differences in the image quality“
- Image quality very, extremely different, varies greatly – from very good to very bad, some very good, others not usable. (several comments) – Quality of the artwork varies greatly across multiple offerings of the same image. The question remains as to which image is closest to the original.
- A “sometime like this, sometimes like that” would fit well here. The quality of the images sometimes differs significantly. No general judgment is possible. The differences are particularly noticeable in objects that exist in countless variations, but you also notice the fluctuations in quality in works that only exist once.
- Some of the images are scans from catalogs which unfortunately have poor quality.
- Often cropped incorrectly.
- The vast majority of images are razor-sharp (in this respect, they could be called very good rather than good). A few undercut this standard. If I ever come across one of these, I usually report it too.

You have two different options in the image archive to share your comments about image quality.
(1) Share your findings directly with the source image databases. Under “details” for the image you will find information about the image database and three icons. By clicking on the middle icon you can “send an email to the person responsible for the database”.

(2)You can also use our rating function to assess the quality of the images.
These ratings influence the ranking when displaying the relevant search results. In addition, the ratings and the number of ratings are sorting options that you can select for displaying your search results list.

Another theme of your comments are the
„differences in color, brightness“
- quality varies greatly and I don’t have a reference model (color wedge) to judge whether the colors are correct.
- sometimes there are differences in the color representation of the same painting and the big guesswork begins as to which one is closest to the original.
- resolution is very different, color calibration of different versions is sometimes so different it’s enough to drive one to despair.
- some of the same works in different chromaticity; makes it difficult to make out the original color.
- There are digital copies of old slides with the rot disease, there are very good ones, especially by large museums. It is a matter of luck.
- Overall, the images are sometimes of very poor quality, especially when it comes to color accuracy.
- The older digital representations are sometimes very poor and vary enormously in terms of color. Some of these are not good photographs of book illustrations.
- The color isn’t always there either.
- The same work of art is sometimes shown lighter or darker. Here you have to do additional research to find out which one is the right one.

Fabian Felder from the University of Basel has tackled this issue in his article „A rustle in the pixel forest! Or could it be a little less yellow?“ and concludes as soon as image archives access already existing heterogeneous image databases the results are inconsistent in terms of quality especially in terms of color.
We have been aware of this problem of different colors in one and the same work from the very beginning (for over 20 years), as Lisa Dieckmann elucidates in her lecture (German only) „Mona Lisa’s sisters – on dealing with redundancies, image quality and heterogeneous metadata“ .
She presents mechanisms with which redundancies in search results can be structured in prometheus and gives an example of the advantage of redundancies: when they open up opportunities for critical reflection on images.

We will be working on additional filter and display options to deal with the mass of images in a workshop with some imaging institutions in November.