Suppose you want to create a web 2.0 design with all those wonderful layers, the first thing you do is hunt down the photos you need. The second thing you need to do is to pull out the sections you want so you can layer those together.
The simplest way I have found to do this in Gimp is not to use the cutting tools to cut out the part I want, but to cut out the parts I don’t want.
First make a copy of your image.
Open the image in Gimp.
Go into the image and select Edit->Copy
( now you have a copy of the full image in the buffer )
Go to the Gimp window and select File->new
( a pop up window will appear with the width and height of your image in it )
Select Advanced Options->Fill with: ->Transparency and click ok.
Now we have a transparent image open. Select Edit->Paste
Then select Layer->Anchor
Now we just have to erase the parts we don’t want. I usually start with the rectangle select tool in the top left corner. Select areas to erase and Click ‘Edit->Cut’
Cut out everything you can using the rectangle-cut method.
Ok now blow up your image so you can see to do the detail work View->Zoom
Now select the eraser ( it looks just like an old fashioned pink eraser ). You can start with a large brush and go to smaller brushes as you need to erase smaller areas. One thing that will make you crazy in Gimp is you select and use the eraser and it ignores you. If this happens click Select->None the erase only works in selected areas.
You will also find the color wand ( tool that looks like a magic wand on the top row is good for erasing sections you don’t want to keep. Select an area then crtl-x or Edit->delete.
Another tip is to erase small sections at a time. If you try to do a large area and erase a section you want to keep you’ll have to do the whole large area again. So erase a small section at a time by letting the mouse button up occasionally.
Zoom in and out as needed to see how you are doing.
Theres a few spots that need to be smoothed out here but the sea plant has been pretty much removed from the original image. Because it is on a transparent background you can paste it into your layered image that you are building.
Removing Backgrounds Quickly in Gimp