1.8.3 Blurred thumbnails

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hue
Posts: 31
Joined: Mon Jan 06, 2020 10:14 am

Re: 1.8.3 Blurred thumbnails

Post by hue »

XnView MP 1.9.10 64-bit

When I go to Catalog then Rebuild thumbnails, all my thumbnails are still blurry. I have to manually select the files from Browser mode then choose View - Rebuild thumbnails. Only after doing that, then my thumbnails will become sharper.

Does anyone know what causes this? Why my Rebuild Thumbnails from Catalog doesn't work?
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user0
XnThusiast
Posts: 2785
Joined: Sat May 09, 2015 9:37 am

Re: 1.8.3 Blurred thumbnails

Post by user0 »

hue wrote: Thu Jan 22, 2026 6:45 am Why my Rebuild Thumbnails from Catalog doesn't work?
try to press 'Synchronize folders...' before pressing 'Rebuild thumbnails' button
hue
Posts: 31
Joined: Mon Jan 06, 2020 10:14 am

Re: 1.8.3 Blurred thumbnails

Post by hue »

user0 wrote: Thu Jan 22, 2026 6:58 am
hue wrote: Thu Jan 22, 2026 6:45 am Why my Rebuild Thumbnails from Catalog doesn't work?
try to press 'Synchronize folders...' before pressing 'Rebuild thumbnails' button
It still doesn't work, the thumbnails generated from (Settings > Catalog) are always blurry. In the end, I decided to just purge all my thumbnails (Settings > Catalog > Maintenance). I'll let XnView generate the thumbnails by itself when I'm browsing. Thanks
jkm
Posts: 260
Joined: Sat May 11, 2024 12:43 am

Re: 1.8.3 Blurred thumbnails

Post by jkm »

hue wrote: Thu Jan 22, 2026 6:45 am XnView MP 1.9.10 64-bit

When I go to Catalog then Rebuild thumbnails, all my thumbnails are still blurry. I have to manually select the files from Browser mode then choose View - Rebuild thumbnails. Only after doing that, then my thumbnails will become sharper.

Does anyone know what causes this? Why my Rebuild Thumbnails from Catalog doesn't work?
Hue, you said ALL your thumbnails are blurry...

This is not necessarily a problem with thumbnail generation or the database, as you're assuming.

It can also be caused by inappropriate thumbnail display settings.

In Settings:Thumbnail, if you have use embedded thumbnail turned on, and "create from original..." turned off, then you will be using the embedded thumbnail, regardless of its resolution.

If your Thumbnail display size (from the View menu, or using the toolbar) is much larger than the embedded thumbnail, then the thumbnail you see will be blurry, because it is being upscaled from too few pixels.

If you DO have "create from original..." turned on, you still have to be careful...

In Settings:Catalog, under thumbnail caching, there will be a size set. If it is smaller than your thumbnail display size, then again, your thumbnails will be blurry.

Maybe you know these things, but it is not clear that you do from your post. So here's something you can try:

Enable "create high quality thumbnail" and "use embedded thumbnail" and "create from original..." and "use sharpen"
In Settings:Catalog, enable thumbnail caching and set the size for 400x300.
Set your thumbnail display size to be 400x300 or smaller.
Now purge and rebuild your thumbnails.

They should be sharp, as long as your display size is not significantly larger than the cached size.

If you don't want to use cached, generated thumbnails, and you want sharp thumbnails, then you should keep your display size equal to or smaller than the embedded thumbnail size. A common size for jpeg embedded thumbnails is 160x120.

Hopefully this helps.