Why are the thumbnails blur?
First some basic info regarding thumbnails: XnView MP has a "view thumbnail size" and a "cache thumbnail size".
How to get sharp, large thumbnails
- In View>Thumbnail size you set the view size, i.e. the size the thumbnail is displayed, but not the size the thumbnail is created and cached.
- By default, XnView MP uses a maximum "cache thumbnail size" of 192x144 for caching thumbnails.
- By default, XnView MP uses the EXIF thumbnails embedded in your image files. The embedded EXIF thumbnails can be read very quickly but the size (width x height) is limited, e.g. something like 150x150 pixels. If you make your thumbnails larger than the size of the embedded thumbnail, they will look blur.
You can force XnView MP to...
1.) ...calculate the thumbnail from the original image if the embedded thumbnail is not large enough and not sufficient.
2.) ...use larger thumbnails in the thumbnail cache.
WARNING: Creating thumbnails from the full image (not the embedded thumbnail) may result in a big slow down of XnView.
You have been warned, if you still want large thumbnails you:
1. Select "Tools > settings..." menu
2. Select "Browser > thumbnail" category
3. On tab "Misc" you will find the setting "Use embedded thumbnail". And underneath there is the setting "Create from original image if embedded thumbnail is smaller than thumbnail size". Check this setting (not recommended, see above warning).
4. Select "Browser > Catalog" category
5. In "Thumbnail caching" panel, set a size for your thumbnails. All thumbnails will be created and stored in the thumbnail cache using this size.
Please check this setting and save your changed settings with "OK".
Your changes in the setting will apply when creating new thumbnails. This means: At first, nothing will happen, because the thumbnails have been built already and are read from the thumbnail cache. Select "View rebuild" thumbnails to force XnView to rebuild the thumbnails and you will see your thumbnails at high resolution.
Note: If you want XnView to apply some sharpening, then check the setting "Sharpen thumbnail" in the settings (Browser > Thumbnail" category, tab "Misc".).