This is my personal favorite method for extraction. Given the right image, it is absolutely precise and leaves edges as soft or as harsh as in the original. To use it, the image should meet the following criteria: 1. High resolution (always use high-res when photoshopping)2. The edges around the subject are distinctly different from the background.3. No small little bits (though there are ways to recover these - you can still use this tool to extract most of the image)4. NO FUR OR HAIR! (You CAN do it, but you will not get a good result. HOWEVER, NO method will give you a good result - you must rebuild hair and fur - to be mentioned in later tutorials. You can still use this tool to get the main image extracted and ready to be rebuilt.) I've chosen the following picture. There's a good color difference between the snail and the background, and the edges are fairly smooth with no itty bitty bits. Perfect for this method
IMPORTANT!!! First duplicate the layer!!! You can do this by dragging the background layer to the little icon showing a piece of paper. A new layer will appear. Then, turn off the background layer (so that we can see how nicely the snail extracted later).
Now we open the extract tool. Go to the filter menu and click on extract
Let me explain the extract screen. 1. Highlighter2. Image recovery tool (very important)3. Zoom4. Preview5. Brush size (I like to use 11 or 20)6. Smart highlighting (you should always have this checked)
We need to start by highlighting the edges. Don't worry about being too exact, the smart highlighting will automatically make your line fit to what it detects as the edge (very useful!). Use a brush of about 11 or 20, make sure you check smart highlighting and go to it.
Once you'e highlighted the entire edge click the fill tool and fill. (If your highlighted edge wasnt completely closed, it won't work, but you can click on the highlighter again and fix the hole, then fill again)
Now hit PREVIEW, NOT OK. If you hit OK now, you can't fix the little problems! Once I hit preview, I dont need to zoom in to immediately notice some problems. Some of the background didn't get erased. If I did zoom in really close I'd also notice that the edges arent QUITE perfect. They will in fact be a little transparent.
This is where that little button I called image recovery tool comes in handy, and makes all the difference in the world. When you zoom in and run it along the edges, they will suddenly become perfect. Some areas, like the ones I pointed to will require you passing over many many times before the extra background disappears. Other spots will only need one pass. Just keep painting with it until you are satisfied that the edges are perfect. (be careful around sharp angles, often they get messed up. If you can't fix it, don't worry, we can fix it later with history brush or quickmask. I will show this in a later tutorial)
When the edges look good, now you can hit ok!