I need to know if there is another way, I always have to wait a day to start using the image and I have a big delay in my progress of work.
Using the rbxasset:// protocol, you can reference materials inside of the content folder in your User/AppData/local/ROBLOX/version<>/content folder.
Some ROBLOX tools and things use this which you can use as examples.
(These obviously are only available locally)
I don't think it's really possible, otherwise you'd see loads of inappropriate images on Roblox.