Thumbor regularly errors on giant JPGs because ImageMagick runs out of memory attempting to generate thumbnails for them. We fixed the very same same problem for giant TIFFs and PNGs with VIPS, which is designed for low memory consumption and resizing of giant images.

Special care should be applied to reproduce the existing conditional sharpening applied with ImageMagick. If the same strategy as for TIFFs and PNGs is used, there will be an intermediary image roughly twice the size of the target. The conditional sharpening kicks in when the target size is at least 15% smaller than the original. With a VIPS intermediary step, it means it would only kick in when the image is at least 15% than the intermediary step. There might be edge cases where the sharpening won't kick in anymore as a result of the intermediary step.