How do i put a background on GIMP 2.6?

Please Read!!! Help with GIMP!!!!!?

• I need help with using gimp or flickr (if it doesn't cost anything). I want to know how to make the background of a picture black. I want to know how to do this particually for pictures of myself,like a pic i would put on facebook,a profile picture. click on the link to look at the type of picture im talking about. please help!!!! http://www.public-domain-photos.com/free-stock-photos-4-big/flowers/african-daisy-on-black-background.jpg and btw this picture is of a flower, i would want it this effect for a profile picture of myself

• Answer:

  That flower could have been photographed with a flat-black backdrop, but you can do background removal after-the-fact. The easiest way to to use a "green screen" background, then do a "fuzzy select" for that background color, adjusting the threshold until you get the right select, approximately. Erase that selection (if you want transparency, copy the image to a new layer, then clear the background layer to white, black, or whatever contrasting color doesn't make you ill when working up close.) Clear the selection to transparent (Edit>Clear or Delete key). This will do a rough removal. Then select all (otherwise it will look like your eraser doesn't work), zoom in, and use the eraser tool to do fine clean up around the borders. It's tedious, but that's often the price of having a lot of control. Play with hard vs. fuzzy edges and brush dynamics to get things with fuzzy edges (hair, sweater, wool hat, Santa's hat trim, etc.) looking about right. If you've used a foreground layer with transparency, then you can insert different background layers to see what the combination looks like, and then maybe tweak some more. If your bacground is not flat, you'll have to the coarse background removal by hand, too. Stroking a boundary path around the face/flower/whatever you want to keep, converting that to a selection, then inverting the selection, then clearing the selection is a good sequence.