Unfortunately, there are two problems using this as a starting image: (a) it has lots of block jpg compression artifacts in the shadow areas and (b) the guy's jacket is so dark that it merges into the background. Fortunately, these can be dealt with.
It was relatively easy to get rid of the JPG artifacts - I just ran it through Topaz's deJpg filter and it looked much better.
Extraction of a subject like this is particularly difficult because there are two distinct regions that must be dealt with separately - the frizzy hair and the sharp, almost straight line edges of the jacket against the background.
I separated the two onto different layers and extracted them separately.
In both cases, I first did a rough selection of the subject using the quick select tool. I then used "refine edges" to optimize the extraction. Since, at this point, you don't know whether the subject is going to be put in front of a light or a dark background, when you are adjusting the "refine edges" parameters, you absolutely must keep switching back and forth between a pure white and a pure black background. One can easily find yourself terribly mislead if you don't do this. Adjust the various sliders until the extraction edges look as good as possible against both backgrounds.
Save the results as separate selections for the two different parts of the subject, the head and frizzy hair, and the torso with relatively hard straight jacket edges.
Even using "refine edges" twice, the resulting selections will never look perfect, so make a 2nd copy of each of them, and carefully tweak each (always checking against both black and white backgrounds) to eliminate any odd looking halos and other edge problems. To do this, I use a combination of painting while in the "Edit in Quick Mask Mode" as well as the other selection tools such as the "Polygonal Lasso" tool.
Because the arms of his jacket were so dark that they blended right into the background on the original, it was impossible to get a good extraction using the above techniques, so, using the polygonal lasso tool, I simply used straight lines for these parts of the selection. If I was doing this for real, I would probably found another photo of a guy in a suit and did a selection on it to get some realistic creases and bumps, and then transfer that to this image.
At this point, you can merge the two sections of the subject and place him in front of any sort of background.
Pay special attention to the areas likely to be most problematic: (a) the transition between the background and the hair, and (b) around the edges of the jacket. They are certainly not perfect, but if you are going for realism, compare them to some of the extractions in this thread.
HTH,
Tom M
