I was able to change lock screen wallpaper but can't change of that screen which comes after sleep on MacBook pro I was looking some ways to customise my mac, and I saw a way to change lock seer wallpaper by keeping the same name "com.apple.desktop.admin.png" as of the automated lock screen wallpaper
 


When i opened my mac after shutdown


I got that blurred image after i closed my mac's flap or lid and even by pressing sleep in the apple menu, how can I change it also?
The best way to fix it instead of going through your cache is to use a free utility called Onyx.

It will enable you to change it very easily to whichever photo you like!