PNG and GIF thumbnails, poor quality

[kileytoo]

Hi all, I was wondering if anyone experienced the same issue: all my thumbs look awesome, but for some reason PNG and GIF images look very poorly, totally unreadable, seems like they are in black and white (as opposed to shades of gray or color.) They are also a lot slower to come up than for the other formats. The thumbs for all other formats like TIFF, JPG, etc. look just fine and are quick. I added a screenshot showing GIF and TIFF thumbs side by side, any help very much appreciated.
(I am using version 9.40 trial on Windows 7)

[admin]

Hi,

high-contrast black and white stuff is more difficult to shrink convincingly than color photos. Not much can be done. If you feel Explorer's thumbnails are better then tick Configuration | Thumbnails | Super-fast thumbnails to use that same algorithm.

Don

[kileytoo]

Thanks, I tried "super fast thumbs" already but had no effect (does not fix the quality issue, does not increase speed).

The issue is not present in Windows Explorer where thumbs for GIFs and PNGs look just like those for TIFFs and JPGs, so if "super fast thumbs" is supposed to show in XY the same thumbs as in WinExp, then is not working on my system. Maybe because it's Win7 64 bits?

By the way, when the issue is not present (for example for TIFF and JPG files) XYplorer does a very good job at showing the high-contrast black and white pages, the thumbs are crisp and detailed, which can not be said for Windows Explorer that shows rather blurry thumbs.

[nas8e9]

Thanks, I tried "super fast thumbs" already but had no effect (does not fix the quality issue, does not increase speed).

Just a hunch, but I'd try:
1. clearing XYplorer's thumbnail cache by way of Configuration > Thumbnails > Clear...;
2. restart XYplorer;
3. enter the folder with the thumbnails to have XYplorer start afresh with those.

[kileytoo]

Thanks, I tried that already (sorry for not mentioning I'm an advanced user and tried a number of things before posting.)
I just checked the image formats but they are all 8-bit images, though there may be some differences such as whether the color/grayscale palette is embedded in the files or not... not sure about that.
I just tried a popular image viewer and all the thumbs show just fine, but I need a file manager like XY that also shows thumbs for PDF files.
I am going to try other programs, gee I never thought it would be so difficult to get decent thumbnails on Windows 7!

[kileytoo]

I was playing with XY Preview feature and found out what the issue is: there's an option called "High quality image resampling," in the preview pane I can turn it on and off at will, but in the file list it is always on for TIFF and JPG files and always off for GIF and PNG files. Not sure how to fix this though...

[admin]

Could you send me one of the originals for testing, please.

[admin]

Thanks.

I made some tests and always with all settings the thumbnails came out totally pretty.

The setting of Configuration | Preview | High quality image resampling just makes in difference in the preview.

So, I cannot explain what you are seeing.

[kileytoo]

Thanks for trying.
I do have "High quality" in the preview options checked/active.
I dont see "High quality" in the Thumbnail options, but it seems to be always on/active by default, right? Because the thumbs for all the other image formats, as well as PDFs, are shown in high quality...

Also, I was wondering if file associations are relevant for thumbnails? Because I used to have some image formats (maybe including GIF and PNG) associated with some old graphics software which may not work properly on Win7-64. I did change this and GIF and PNG files are now associated with the standard Windows Photo Viewer, but you never know...

If I cant fix the issue, or find another software solution, I may end up converting all the GIF and PNGs images to TIFFs, the three formats are all lossless so it shouldn't be a problem.

[admin]

I dont see "High quality" in the Thumbnail options, but it seems to be always on/active by default, right? Because the thumbs for all the other image formats, as well as PDFs, are shown in high quality...

That's correct, "High quality" is implied with thumbnails when "super-fast" is unticked.

Nevertheless there are some internal conditions that *might* explain what you see. The next version *might* improve the situation.

Also, I was wondering if file associations are relevant for thumbnails? Because I used to have some image formats (maybe including GIF and PNG) associated with some old graphics software which may not work properly on Win7-64. I did change this and GIF and PNG files are now associated with the standard Windows Photo Viewer, but you never know...

Well, yes, you never know... these image files are loaded through GDI+, and who knows who is intercepting where and what...