1.8.3 Blurred thumbnails

[Smeeta]

The thumbnail on folders in browser view mode looks clean and sharp (left), while all the thumbnails of the images inside the folder are very blurry and unsharp (right).

I'm aware of settings as "sharpen thumbnail", "use embedded thumbnail" and few other managing settings such as the thumbnail size and catalog storage ones.

Apparently there are familiar topics which are perhaps related to this problem:
The problem back then was the opposite and seems to be fixed
viewtopic.php?t=39916

The user(s) were reporting this bug and it was stated, that the problem is with specific file properties (8bits+colormap), but it led to no conclusion - while other image viewers seem to be be able to handle it well.
By chance my images look familiar to the reported ones, maybe it also afflicts the thumbnails somehow as well?
viewtopic.php?f=62&t=46440

[user0]

upload your original image somewhere and share the link

if you are talking about

• folder and file thumbnails
  try to (in Settings > Catalog):
  - 'Delete all' from Catalog OR
  - Disable Catalog

• folder thumbnail and image in Preview panel
  - check 'High zoom quality' settings (in Settings > View)

[Smeeta]

https://imgur.com/a/gqDJXIh
https://www.dropbox.com/scl/fi/l5czglpr ... h8r44&dl=0

Additonally to test it out, I've downloaded the imgur link and compared it to another image browser (Pictureflect).
https://www.dropbox.com/scl/fi/1l9q7ma4 ... vu1ga&dl=0

I'm also using the "Rebuild thumbnail" function in the View menu bar (Ctrl+R) to test if it has improved, when changing settings. Catalog On/Off doesn't affect the generating quality here. If I change the size of the thumbnail itself or the way it is stored in the catalog, I immediately see changes when using the rebuild function.

The "High zoom quality" settings affect the image itself, not the generating of the thumbnail. Either way by changing from None, to Bilinear, to Lanczos it doesn't change. The settings in the "Thumbnail" tab "Create high quality thumbnail" and "Sharpen thumbnail" greatly affect the generating of thumbnails, but I've already turned them on.

[user0]

ok, you are talking about folder and file thumbnails

1. increase size of cached images from default 192x144 to the size of your thumbnails (in Settings > Catalog)
2. open folder with your files, select them or select none
3. press Rebuild thumbnails (in Browser > View)

[Smeeta]

Yes, I'm talking about how the thumbnails of images inside a folder are blurry, while the thumbnail of the folder itself (using the 1st picture inside of it) is sharp and clear.

The catalog itself doesn't matter in this case, I've disabled it, the quality was still bad when I've downloaded the images from imgur/dropbox again to the desktop and viewed them there.
I've used the "Get thumbnail size" function to make the catalog the same size as the thumbnails, while catalog was enabled.
As I stated previously, I'm already using the thumbnail rebuild function in the Browser - View menu to check, so the thumbnails are freshly generated.

Perhaps it helps to clarify I'm using 256x356 as the thumbnail/catalog size, if you are using a much smaller size or a default image format such as 192x144 you probably won't spot a difference because it's too small.

This is the reason why I've linked the 2nd forum topic in the first post, the problem seems to be about the file properties. For some reason XnView has problems with those as stated by Pierre before, without conclusion.
viewtopic.php?p=194330#p194330
But it seems to affect those thumbnails and viewing the images in view mode as well.

[user0]

I cannot reproduce with disabled Catalog as well


try to reproduce starting from default settings:
1. rename your xnview.ini file (check location in Settings > Integration > Paths)
2. start app
3. change default Settings
- disable Catalog
- disable Show 4 thumbnails in folder's thumbnails (instead of 1) guess you use it
- set Custom thumbnails size to 256x356
- press OK
4. select Custom in Browser > View > Thumbnail size
5. restart app

ps. linked topics are about different issues

[xnview]

please send your xnview.ini to be able to reproduce...

[Smeeta]

I followed the steps to reproduce by creating a new xnview.ini config and changing the listed settings.
https://www.dropbox.com/scl/fi/kqt9nbuc ... bapdq&dl=0
My new config does still not seem right. You are sure your folder thumbnail couldn't be sharper with settings as "Create high quality thumbnail" "Sharpen thumbnail"? Those were already active on a new default xnview.ini config (besides "Use embedded thumbnail" was also checked, but doesn't make a difference).
I've attached the original xnview.ini as a .zip here.

[user0]

well, it looks like you are right, its related to viewtopic.php?t=39916

- ☑ 'Sharpen thumbnail' does not apply to thumbnails of 8bit grayscale JPEG, PNG files
- ☑ 'Use gamma correction' does not apply to folder thumbnails
- ☐ 'Create high quality thumbnail' still applies to folder thumbnails

[xnview]

Thanks to your detailed description I can reproduce the problem.

[Smeeta]

I'm glad the bug was finally found and not an error on my side, thank you for bearing with me
On a sidenote, does this also affect the problem of the previously second linked topic due to the 8bit grayscale property?
viewtopic.php?f=62&t=46440

[xnview]

This problem is supposed to be fixed in XnView MP 1.8.4. Please check and confirm the bug fix here.

[Smeeta]

The new 1.8.4 version fixed the bug successfully, thank you again. But still is there some insight for the other linked thread's bug being connected to this topic? On second thought I seem to be affected by this bug as well, due to using the same kind of images.

Should I refer this solved thread to the other thread to basically put them together?
viewtopic.php?p=194330#p194330