I wonder if there is a way to copy the link of an attachment from the Forum Gallery and put the attachment in the ArtRage Gallery?

I find that I can quite easily attach a reproduction of my painting if I attach it from my computer to a thread in the forum titled "Gallery" but when I want to attach the same reproduction of the same file from my computer into my personal gallery in "The ArtRage Gallery" it will tell me that it is too big to load when it is bigger than 500 kb.

I'm assuming that when one adds the attachment in the forum there is some sort of widget thing going on in the background that converts the file to a "Forum" compatible file size thingy. Is there a way of copying that resultant reduced size picture into my "Artrage Gallery". If it has already been converted, it seems silly to me to have go back to my computer and resize the same picture just so that I can post it somewhere else in the forum.

I'm just trying avoid the "harrumph" feeling and to streamline things a little, 'cos sometimes I don't realise I'm uploading a file that is just outside the size parameter until it kicks me out.