elementaryOS-lockscreen-bgreplacer

This script is meant to be used in Elementary OS 6 Odin. You must be root user in order for it to work. You need an image called texture.png inside your Pictures folder. Everytime greeter is updated, you need to run this again.

What do you need

gnome-settings-daemon >= 3.27
libaccountsservice-dev
libgdk-pixbuf2.0-dev
libgranite-dev >= 5.5.0
libgtk-3-dev
libhandy-1-dev >= 0.90.0
liblightdm-gobject-1-dev
libmutter
libwingpanel-2.0-dev
libx11-dev
meson
valac
git
imagemagick-6.q16 (For blur version)

To install dependencies:

sudo apt install git
sudo apt install -y gnome-settings-daemon libaccountsservice-dev libgdk-pixbuf2.0-dev libgranite-dev libgtk-3-dev libhandy-1-dev liblightdm-gobject-1-dev libmutter-6-dev libwingpanel-dev libx11-dev meson valac imagemagick-6.q16

You need to put any png image called "texture.png" (with your desired resolution) in /home/your_username (or "$SUDO_USER")/Pictures, otherwise this won't work!

Installation

Become root user

sudo -i
cd /tmp/

Clone the repository

Open a terminal and run the following git command:

git clone https://github.com/Blackmanx/elementaryOS-lockscreen-bgreplacer bgreplacer
cd bgreplacer

Put an image in Pictures folder called texture.png (with its png format).

Run script

bash background.sh

or, if you want blur

bash background-blur.sh

Restart and done.

Source

https://www.debugpoint.com/2021/07/change-lock-login-screen-background-elementary-os/