Whether you are doing scrapbooking, cards, or collages, you might want to extract a particular element from a photo to use separately as a decoration. There are multiple ways to select the outline of an element, ranging from the simplest Magic Wand to the Object Extractor. What tool you will use will depend on various factors, namely the type of element you need to extract, and the background that needs to be removed. However, there is one technique that is less known yet it seems to be the easier to use than most of the others.
The starting image
For this demonstration, we will be using this image where the flags will be extracted from the background.
Traditionally, one could consider using the Point to Point selection tool, and since this element has some straight lines, it might be feasible. But let's looks at a different approach.
There is an icon in the Layers Palette to let you edit a selection.
If you had a selection, that area would have turned pinkish but here, you have no selection yet. What you should notice, however, is that there is now an additional layer in the Layers palette, that is all black and is named Selection.
From this point on, whatever is black, is NOT selected. So in order to add a selection, you will paint it in white.
Brush the selection
Activate the Brush tool set to a regular round shape, and a size that matches the element you want to extract. You can start with a larger brush and use a smaller one later.
As you start painting in white over the area you want to select, you will notice that area turning pink. That is exactly what you want. Continue painting in white all over the area you want to extract. If you make a mistake and you painted outside of the edge, simply paint back in black, which will remove that selection.
This way to select is the same as when you paint with the Brush (in fact, you are!) so if you have a straight line to select, you can click at one end, hold the SHIFT key and click at the other end and it will create a straight line between those two clicks.
Edit the Selection
Once you are done painting all the areas you wanted to extract, click on the Edit Selection icon again. Now, that white section you painted will become an actual selection with the familiar "marching ants".
If you want a perfect result, you will want to zoom in and check your selection. If you see some marching ants where there shouldn't be any, it means that you might have just missed a few spots.
How to fix this will depend on the size or location of these missed spots. You could simply use the Freehand selection tool and, holding the Shift key, you can circle around the missing spots, or you can go back to use the Edit Selection and paint on the area.
Now, it is time to either remove the background or copy your selected area and paste as a new image.
Although this technique is not the only one, it seems to be the most flexible to use in just about any situation (unless you have a solid color background where you can just use the Magic Wand, but that is not common). Check out this example of a photo where this technique was the only option available.