A nice big hi
res picture works best.
I use Photoshop 6, it's an older version and not as user friendly as the newer versions but this one is the one I taught myself on.
I first zoom in close around the
rim of the coin 200%. I then select the "background removal tool". I don't use the "select color tool" as I prefer to manually go in up close. This gives me more control of what gets removed.
I select black as the background rather than the "transparent" and I begin moving the
circle "paint brush" all around the coin. I zoom in so I can see the very edge of the coin. I then "paint" the background black. I ever so slightly overlap onto the coin so as to give a nice crisp edge. This can be difficult if it is a low
res picture because the pixels will be huge when you zoom in. A high
res picture has smaller pixels.
I then finish removing the background with the circular paint tool. I can make the
diameter as big or small as need be to get into every nook and cranny of the coins edge. I can also use a "block" tool to do large areas.
Once the background is black (or white or whatever color you choose) I then use the "adjust image" tab. There is a selection for "Auto Adjust image" I click that as it is usually smart enough to correct color and contrast on it's own. If not I click the "Adjust color" tab and back off the
red until the image looks like the coin in hand. I do the same for the other colors.
Then I move on to the "Adjust Contrast and Brightness" tab. Again I play with the values until it looks like the coin in hand. Usually this is minimal as over compensating with contrast and brightness makes the coin look bad.
If the photo is out of focus there is a "Sharpen" Filter which sharpens the edges. Again there is a way to crank this up more or less. A lower "sharpening" works best.
That's really it. Very simple but you need a steady hand. The "Step" backward tool is great for when you mess up!