Barbara Urquhart wrote:
Hi there,
I wonder is you could advise me how to upsize, increase both size and resolution for enlarged printing. I find that if the initial picture is not the best then it enlarges so poorly. Is there a way of getting a good result?? I am using Photoshop 7. Is there a good software for doing this? thanks,
Barb
"I find that if the initial picture is not the best then it enlarges so poorly."
In computing, the principle is called GIGO, "garbage in, garbage out." More colloquially, "You can’t make a silk purse out of a sow’s ear." If the initial shot isn’t good, you may be able to improve it somewhat with processing (sharpening, curves, etc.), but it is unlikely that such a shot, even after processing, will scale successfully.
"… upsize, increase both size and resolution for enlarged printing."
You can increase the pixel dimensions (size) and alter the resolution (PPI), although in this case I believe that you are confusing resolution with detail. Altering the resolution will _not_ increase the detail. If an image feature is indistinct at 300 PPI, it will still be indistinct at 600 PPI; you cannot add information which does not exist in the shot. All that the PPI resolution determines is the number of pixels per inch, it does not determine the amount of detail represented.
Results will depend greatly on the nature of the subject. I will use an example I have seen used here before because it is apropos. A portrait shot at, say, 1200 x 1600, which prints well at 8" x 10", will probably incrementally scale up to 16" x 20" acceptably and still appear fairly clean and sharp. A photo of a graduating class of 120 people at 1200 x 1600, printed at 8" x 10" and with barely discernible individual faces, which has been scaled by the same amount will reveal no more individual facial detail of the subjects at 16" x 20" than it did at 8" x 10". It is the nature of the subject and the way that the human eye functions.
There are some techniques which do show a degree of success in reasonable amounts of upsizing, especially if you start with a very clean, minimum jitter (tripod mounted) original. One that I have used fairly successfully for shots taken at the Brickyard 400 is the "10% increment" method. Rather than go directly to the target size, increase the size in 10% increments until the eventual target size is reached. Apparently the algorithms are much more accurate when dealing with the smaller changes than with larger changes, which possibly has something to do with the relative difference in the amount of data which must be manipulated. There are actions available on the Web which will do incremental resizing for you automatically. Give it a shot. But don’t expect to start with crap and end up with gold. ‘Tain’t gonna happen, no matter how hard you wish.
Cheers,
Scott
