If you right click on the folder in PCManFM-Qt (Lightweight file manager) and select ‘Properties’ you can change the folder icon with something from the system’s icon files.
- Right click on the folder then select ‘Properties’
- The File Properties window will open; notice the file icon button to the left of the text box containing the file’s name. Click on the file icon.
- A window will open allowing you to ‘select an icon’ from /usr/share/icons.
- The file type of the icons is .svg
I hope that helps. I am not sure how to create a .svg file, so I usually just use the icons supplied by the system. I’m not sure how to get a custom picture on your folder icon, which I assume is what you wanted, but I hope this helps you to further customize your system.
If you can find a way to convert the image that you want into the proper file type, you should be able to create your own directory of custom images.