How do I change the lock screen image on OS X?

To lock my Mac, I hit Ctrl-Shift-Eject, which puts my display to sleep. When I get turn it on again it asks me log back in and displays the current image in the desktop cycle as a background. I would like to change this image.

I have tried onyx's Parameters > Login > Background but that changes the static image on the startup login screen.

Is there a way to set a static image for that lock screen?

Solution 1:

Mountain Lion defaults the lock screen background to the last desktop background image that was up before the computer locked. AS, Yet, the only way to influence this behavior in 10.8 is so set a static background image that you don't mind having as your lock screen, or use an app like Lock my Mac

Otherwise, here's how to Replace the Login Screen Wallpaper in Mac OS X Lion/Mountain Lion

1. Open the image you’d like to use for the wallpaper in Preview and convert it to PNG format by clicking File -> Export.
2. In the dialog box that appears, select PNG from the Format dropdown list and change the filename so it reads “NSTexturedFullScreenBackgroundColor.png”.
3. Back up the original wallpaper image by opening a Finder window, hitting Shift+Command+G and typing the following path:

/System/Library/Frameworks/AppKit.framework/Versions/C/Resources/

4 .Now copy the NSTexturedFullScreenBackgroundColor.png file to a safe backup location.

5 . Then click and drag your new image onto the Finder window so it overwrites the original. You’ll be asked to authenticate, so click the button in the dialog box that appears and type your login password when prompted. Choose to replace the original file when prompted.

That’s all that’s required, but you’ll have to reboot your computer for the change to take effect.