On 04/24/2014 12:29 PM, Aaron Schulz wrote:
This is similar to what I proposed to Ori. For multi-page file (pdf,djvu,tiff) we'd prerender base thumbnails and use them for downscaling in thumb.php on demand. The base thumbnails would only be so large (e.g. not 10000px width) since there isn't much use case for massive thumbnails vs just viewing the original. This would also apply to single page TIFFs, where one reference thumbnail of reasonable size would be used for downscaling on demand.
It might even improve performance to do this for all (or at least overly large) images after looking a bit more into the distribution of typical thumb sizes and their quality when scaled from a reasonably-sized base thumb. With higher camera resolutions even JPG originals can be fairly large. 2560×1600 for example should cover the vast majority of current screens well, and could be referenced by the MultimediaViewer on high-res screens where it currently falls back to the (potentially huge) original.
Gabriel