This paper deals with the permanent storage of previews for file content. In particular, it tries to define a general and widely accepted standard for this task. That way, it will be possible to share these so called thumbnails across a large number of applications.
The current situation is, that nearly every program introdues a new way of dealing with thumbnails. This results in the fact, that if the user uses 4 or 5 different programs, they will end up with 4 or 5 thumbnails for the same file. It's obvious that this is not only a waste of the user's disk space, but also makes the managing of large collections harder.
But why does a program use thumbnails? Often these are presented in file operation dialogs to give the user a hint what a certain file is about. This can be seen as information in addition to the plain filename which helps to identify the desired file faster and more easily. But the idea isn't limited to images and file operation dialogs. The additional value of previews is also applicable to other file types, like text documents, pdf files, spreadsheets and so on. The reason why this isn't deployed widely so far is, that it requires a lot of effort and is only of little use for a single program (for example, if only the spreadsheet program can create and view it's previews). But imagine if your filemanager could display all these previews too, while you are browsing through your filesystem.
If there is a general accepted, file type independent way how to deal with previews, the above sketched vision can come true. Every time an application saves a file it creates also a preview thumbnail for it. Other programs can check if there is a thumbnail for a specific file and can present it. This proposal tries to unify the thumbnail managing and constitutes the first step to a better graphical desktop.