Viewing mountain crystals from all angles and spotting the little details in aerial photographs: thanks to a new viewer, this has now been possible in E-Pics, ETH Zurich’s image management platform, since 2015.
Why a new viewer for E-Pics?
The new E-Pics viewer all began with a desire to provide a 360-degree perspective of the rocks in the image catalogue of ETH Zurich’s Earth Science Collections. At the same time, Bildarchiv Online wanted to offer its aerial photograph collection with a good zoom to enable users to see the images in detail. Neither of these ideas was possible with the previous Viewer.
Given the sheer number available on the market, the first challenge was to find a decent viewer. Secondly, it had to be incorporated into the Digital Asset Management (DAM) software Cumulus and be able to cope with such a large number of images (currently more than one million). Ultimately, these two challenges narrowed down the choice considerably.
Advantages of the new E-Pics viewer
The Ajax-Zoom viewer more than fitted the bill. Moreover, the viewer software could also be used for other applications at ETH-Bibliothek in future. Consequently, it was selected for implementation.
The viewer’s zoom is smooth and loads immediately, which means users can especially zoom deeply into aerial photographs. The images are opened in a new window so they can be viewed as largely as possible.
Figure 1: Zoom viewer, full screen, 18%
Photo credits: ETH-Bibliothek Zurich, Image Archive / photographer: Swissair Photo AG (Zurich) / LBS_R1-734407 / CC BY-SA 4.0
For a better overview, the viewer displays a thumbnail of the image at the top left of the screen while zooming. If need be, this can be faded out manually.
Figure 2: Zoom viewer, detail, 100%
Photo credit: ETH-Bibliothek Zurich, Image Archive / photographer: Comet Photo AG (Zurich) / Com_F64-02145 / CC BY-SA 4.0
The images in the viewer are displayed as an “image pyramid”. In other words, the images are saved in different resolutions and subdivided into individual image tiles. Google Maps works according to the same principle.
If the user zooms in on an area of the image, only the image tiles from this section are loaded. These image tiles can be created manually, automatically or “on the fly”. Between 100 and 400 image tiles per image are created depending on the image size and resolution.
There are many possibilities for integration and adaptation. The colours and layout can be adjusted with more than 300 Parameters.
A practical E-Pics example: incorporating the viewer
The viewer is activated via a URL (e.g. http://viewer.e-pics.ethz.ch/ETHBIB.Sternwarte/index2.php?id=ETHBIB.Sternwarte_KGS_550-99) and can thus be integrated in various applications. In the following example, the URL is directed to the image with the image tiles via the “zoom Icon” (highlighted in yellow).
Figure 5: Zoom view of an image from the Collection of Astronomical Instruments catalogue
Photo credits: ETH-Bibliothek Zurich, Collection of Astronomical Instruments / KGS_550-99
So far, our experiences with the viewer in E-Pics have been positive. The software runs stably and we have not been able to identify any major synchronisation problems between the source system E-Pics and the viewer software. We would be delighted to receive any feedback from our users. Our team can be reached via email to firstname.lastname@example.org.
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International Public License.
DOI Link: 10.16911/ethz-ib-2472-en