Windows 8 is REDUCING the quality of wallpapers

Hi,

Thank you for choosing Windows 8 and joining us on our community.

 

It looks you are not able to set images as wallpaper with their actual size as they are getting compressed.

 

Could you answer few questions:

1.        What exactly happens when you set an image as a wallpaper?

2.       Is the image file getting compressed or only the image on the desktop getting compressed?

3.       Have you installed any program which compresses files or images?

 

I would suggest you to follow these steps to change the display settings and check.

 

a.       Right click on desktop.

b.      Click on Personalize.

c.       Select Desktop Background.

d.      Select picture position as Fill from the drop down list.

 

Reference:

Personalize your PC

http://windows.microsoft.com/en-US/windows-8/change-backgrounds-pictures#1TC=t1

 

Hope it helps. For further queries feel free to come back.

Dear Tadasha Mishra,

thanks for answering!
I will try to answer your questions as detailed as possible:

1.1. JPG files: If I set an image as wallpaper, it is getting compressed and stored in "%USERPROFILE%\AppData\Roaming\AppData\Roaming\Microsoft\Windows\Themes\" and is renamed to "TranscodedWallpaper" (without a file extension). Shortly after that the same compressed image is also stored in "%USERPROFILE%\AppData\Roaming\AppData\Roaming\Microsoft\Windows\Themes\CachedFiles\" with a filename beginning with "CachedImage" and ending with ".jpg".
The files are much smaller (< 1/2) than the original JPG file.
In rare cases, very big images can also result in a black background.

1.2. PNG files: same as above but they are only converted to JPG without getting compressed. The resulting "TranscodedWallpaper" and "CachedImage_XX.jpg" even tend to be bigger (filesize) than the original PNG file and show no artifacts.

2. The original JPG file remains untouched; only the (cached) desktop image is getting compressed and stored in the folder(s) as written above.

3. I have no programs installed as this is an absolutely fresh install of Windows 8 with no additional programs. Reproduced on two different PCs (one 32 Bit and the other one 64 Bit Windows 8)

(4.) The "Fill" option is already selected. Even the other options don't help as they only change the way the image is displayed but the compressed image still has its artifacts.

P.S. This is definitely a bug! In Windows 7, a JPG wallpaper was only _copied_ to the "Themes" folder mentioned above and renamed to "TranscodedWallpaper.jpg" (with the file extension) but the image itself remained untouched in Windows 7.

Someone needs to report this to the engineers/developers!

I have the same issue.  I'm setting the desktop background using a call from a C++ program:

I have same problem. Any ideas how to fix it?

So I know this is suuuper late, but if you still want to know, I can help. Windows compresses .jps when setting desktop wallpapers, but not .pngs. All you have to do to stop the terrible quality reduction is open the image you want in paint and save it as a .png instead. Then, in its location in windows explorer, right click and "set as desktop background". Again, really sorry this is so late. 

Thats i know, but i must convert any jpg images to png? O_o (I'm doing exactly the same, but I want to work properly out of the box)

Know a lot of perversion =)