Even though we have put transparent image as our login pictures, the white square box will still be there. This indicates that there is lack of transparency in displaying our login pictures.
But now, it’s not a problem. Mac OS X Hints has put up a really interesting topic about how to enable this transparency. All of the steps are done in Terminal.
In their article, Show User Pictures with Transparency, I can conclude three main steps used in adding transparency to login pictures.
dscl . -read /Users/[your username] Picture
This will help you identify which image you’re currently using for Desktop picture. As a response, Terminal will return the path of the picture.
Picture: /Library/User Pictures/Animals/Butterfly.tif
Don’t forget to copy the path to this file, as you will need it later.
sudo dscl . -delete /Users/[your username] JPEGPhoto
As explained inside the article, we will have a JPEG version of the image. This JPEG version is the culprit behind the inability to display alpha transparency. With the command line above, this JPEG version will be removed.
sudo dscl . -change /Users/[your username] Picture ‘/Library/User Pictures/Animals/Butterfly.tif’ ‘/Library/User Pictures/New/Smile.tiff’
The first parameter under the single quote is the path to the current login picture. This is the path that you’ve copied to clipboard at the 1st step.
The second parameter is the path to new login picture that you want to use. Obviously, use new login picture with some transparencies. You need to provide the full path of it. (Hint: You can use drag and drop to accomplish this task)
As usual, logout for the change to take effect.
I cannot fully guarantee that this trick will not harm your Mac. The only thing I can prove is that this trick didn’t harm my Mac. So, you can try it for your own risk.
Screenshot above shows how awful the login pictures without transparency compare to the one with transparency.
There are several resources you can use to beautify this trick.