# Login Background Image Not Setting Correctly



## Parad0x_ (May 31, 2017)

Hello, I created a automator application to aid in changing the login screen background for company computers. I have gotten the script to work perfectly but have noticed some images take some strange tweaking to get to work correctly.

To put it simply my app deletes com.apple.desktop.admin.png, asked user for an image file through finder, copies and pasts the image into /Library/Caches, and then renames the image file to com.apple.desktop.admin.png and locks it to prevent non-admins from changing it.

Some issues I am already aware of is that the image file must be in .png format and the same resolution as the Mac. Most of what we use is 1920 x 1080 so our graphics person exports the images in this size. I also use preview to re-export non-png images into png.



My problem is that when doing this something breaks. Even though the images are 1920 x 1080, are .png format, and have the same name as the old image; my changes don't allow the image to be reset as the login background. The only fix I have found is to use preview and downsize the images to 1280 x 1024, save, and then change the size back to 1920 x 1280. If anyone knows how to fix this issue so I don't have to downscale and then upscale, please let me know.

We are currently using OS X Sierra.


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## justmacanswers (Jun 16, 2017)

Thats a strange work around. The only thing I can think of, is to make sure your ownership settings are correct.


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## sinclair_tm (Mar 11, 2005)

Which version of OS X are you running? Used to be all you had to do was replace the file like you have done. But now OS X caches everything, but I have yet to figure out where those cache files are so I can wipe them as well. This caching also has kept me from changing system dialog boxes too like I once did to personalize my Macs. Really helps if someone tries to walk off with it, but my name is in the system dialog boxes. Makes it hard for the crook to explain to the cops.


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