I’ve been playing with Picture Libraries, and I began to wonder, where are the thumbnails stored?
Picture ListItems have 3 different sizes…
And the original image itself:
Looking at the URLs for these image, the thumbnails seem to be under a hidden folder in the Picture Library called
_t, and the previews are under
_w . Looking at the Picture Library in SharePoint Designer, the images themselves seem to be related to each other by filename:
Looking at the file sizes, you can see a massive difference in the file sizes between the original and the thumbnail – 496k vs 5k, or about 1% the size.
Neat, simple. I’m not sure what it is generates the thumbnails, but they’re definitely done at upload, and it seems to make a pretty good job of it.
Of course, image files being stored in a document library don’t have thumbnails, so that won’t work so well if you’re wanting to display thumbnails in something like the Search Results.