Using Genuine Fractals I have blown up the image to 10" x 8 " at 360
d.p.i., ideal for printing on my Epson 750. I have also used the Bicubic
resample filter in Paint Shop Pro to interpolate another copy of the image
to the same size. To save you download time I've simply selected a small
section of each image around the mouth. This section shows the differences
between the techniques quite well.
As you can see the difference is small but noticeable. It may not be
as visible on your screen as when printed, so to demonstrate better, I've
zoomed in to both these images:-
 |
 |
|
|
|
As you can see the close-up on the right is noticeably sharper, but interestingly it does not accentuate the camera's JPEG artefacts as much as the interpolated image. It does however make the gap between the teeth look slightly larger, which could be considered a fault. For reference, this is the original image magnified to approximately the same size:-
