Usually only one record is stored in E-Pics, from which other formats and sizes are converted. This so-called "digital master file" should meet a few basic requirements (as of March 2019):
- Picture format: Tiff format
- Color depth: 8 bitImage resolution: 300 dpi
- Image resolution: 300 dpi
- Color profile: RGB
- Image size: Max. 150 MB
- No layers
In the case of art photography, 16 bit TIFF and 600 dpi may be useful, but for photographs / scans as documentation, 8 bits are sufficient. Jps can also be master files, provided they are imported with a high resolution. TIFF is always recommended.
A baseline Tiff is the best prerequisite to ensure that these master files can be long time archived later on. These tiffs do only have a very specific number of elementary tags and are therefore less complex (see also Tiff 6.0 Part 1). The ETH Library compiles a specification for long term archiving.
The Cumulus software can handle a large number of different formats. It is also possible to archive RAW, psd, png, gif, etc. However, according to current knowledge, such formats cannot be long term archived in a reliable way, so that these formats may only be saved for the next few years in Cumulus, but not intended for long-term archiving. In addition, E-Pics emphasizes the fact that the frontend contains formats that customers can use in a simple and versatile way. Therefore, Tiff (or jpg, if Tiffs are not available) are also recommended for this purpose.
Please be aware that E-Pics is not a database for the long-term preservation of image files. Unfortunately, our customers repeatedly misunderstand this. Images in E-Pics that need to be archived in a suitable system for a long time, have to be available in a valid form. Uploaded images and metadata are stored unchanged in E-Pics. When uploading images, no validation takes place. Therefore, the validity of the images is the responsibility of the customer. Since errors can occur during import, if possible visually check the images immediately afterwards (preview).
