Yesterday, 07:55 AM
(06-13-2025, 11:29 PM)kdaunt Wrote: Here's the situation:
1. I edit a jpg image from my camera, add a layer or two and complete other edits, then export as another jpg.
2. When I open the jpg, either to preview it in windows or load it into Gimp, it takes noticably longer to load and render.
3. The image initally shows but is out of focus, then seems to load the second layer and appear sharp.
Does the jpg format maintain the two layers?
How can I fix this?
Thanks in advance.
A Jpeg image contains one or more thumbnails. Looking at the metadata, those from my camera come with a 160x120 "ThumbnailImage" and a 1620x1080 "PreviewImage".
To speeds things up, many applications first decode one of the small images and display it (perhaps upscaled, therefore blurry) and then replace it by the actual image when it is ready (this takes 10-20 longer to decode).
In addition, many applications also maintain a cache of thumbnails for images they have already loaded so when you return to the image it loads even faster because going to the cache avoids a lot of disk I/O. But the JPEG you just edited isn't in cache yet.
So it's not Gimp, it is your system reacting to a new image. On the Gimp side, in the JPEG export options, what you can do is make sure that Gimp saves a thumbnail, so that the thumbnail is updated with the edited image.