One thing I have to do more often then not is enlarge my digital prints for printing. Unlike with traditional film which you can scan on a flatbed scanner and get incredible resolution for printing, I have to use Gimp or Photoshop to enlarge my prints for the final print size. Most of the time I am not enlarging my prints by that much but since I am using the Sigma Sd-14 Digital camera with the Foveon censor and it only has 4.6MP I have to enlarge most of my prints by some degree for printing. The Sigma Foveon digital files do enlarge extremely well and outperform other cameras with higher Megapixels count. But what if I wanted to make a print 63x42cm? Enlarging a digital SD-14 file from 2640×1760 pixels (4.6mp) to 7500×5000 pixels (36mp) is no problem for Foveon but I need a program to enlarge the print. How well will the open source Gimp performe up against Photoshop CS2 and Qimage (version. 2010.210)? Well lets find out.
I started out with the native resolution Sigma file and enlarged them in Gimp, Photoshop and Qimage. Lets see the results, you are looking at a small area in the print at 200% resolution or zoom in Gimp.
Qimage creates the best version with a cleaner, sharper and less pixalated image. Gimp comes second and then Photoshop. But have in mind when I enlarged the file in Photoshop I used Bicubic sharper setting instead of Bicubic smoother. When I enlarged the file in CS2 via bicubic Smoother it created a better photo than Gimp. But not by much. Does this mean Gimp is crap? No not at all, the difference was minor and hardly visable. When I printed these files on photographic paper via Epson 1270 printer and from a normal viewing distance it was hard to tell them apart but there is a small difference. The Gimp and Photoshop image look the same while the Qimage program clearly does a better job.
If you want to make your own print and download my A4 test print which I used for evaluation. The test print show the three version at print resolution of 7500×5000 but only the area I was looking at. Also if you want to redo this test you can download the original Sigma file in it’s native resolution.
Now I only need to get Qimage to work on Ubuntu via Wine.