You're not wrong! Windows 10 has a feature that optimizes the desktop wallpaper to a compressed image for quicker loading at boot (so they claim). Someone on here added this cool little tweak that disables that compression and thus renders the image in the full quality (just as it did in Windows XP). Open cmd as admin and run this. Code: reg add "HKCU\Control Panel\Desktop" /v "JPEGImportQuality" /t REG_DWORD /d 100 /f
Not only Windows 10. All Windows since Vista transcode/compress the Wallpaper to 80%/85% quality. However, only under Windows 10 it is configurable.
Yes, GOD666 is correct. By default a compressed version is displayed. Can't confirm if the reg works as I don't care!
You need to reboot for it to take effect (or at the very least restart explore.exe). But honestly, if you're using a good 1080p display with a good 1080p photo that isn't already compressed, you'll likely not notice any difference. The folks who do notice the difference is if the photo was already pre-compressed in which case Windows came along and compressed it a 2nd time which degraded the image. Or if you have something better than 1080p (4k perhaps), I've been told you notice it there too. The above tweak basically tells Windows to leave the imagine alone at 100% quality, uncompressed, and untouched from being optimized (which is exactly how Windows XP did it).