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Testing Genuine Fractals
Does it really deliver sharper digital image enlargements?
 Anytime one changes the original digital image file resolution to a different resolution and file size, the pixels in that file must be interpolated, and that interpolation almost always degrades the image. This is especially true when enlarging image files. The old adage, "you can't get something for nothing" is usually true, but when it comes to Genuine Fractals, it comes pretty darn close to producing a freebie: greater resolution with very little cost in quality loss! Altamira's Genuine Fractals software is a plug-in for Photoshop that they claim can "...enable you to increase the resolution and size of your images while preserving original sharpness and detail."
We've been using GF for two years now, with good results, and have been recommending it to our customers who have digital image files that they want enlarge, instead of having to rescan the original -- either because they don't have access to the original art or their own scanner could not resolve any higher. Some artists use GF because they don't want the inconvenience of having to spend additional time retouching or editing a larger version of an image that is finally "just the way they like it".)
NOTE: Altamira is being bought by LizardTech. You can purchase GF and learn more about the product at http://www.altamira-group.com/
- Genuine Fractals 2.0 sells for $159.00 (Windows or Macintosh)
- Genuine Fractals 2.0 LE sells for $49.95 (Windows and Macintosh)*
- Genuine Fractals PrintPro 1.0 sells for $299.00 (Windows or Macintosh)**
*LE is designed for the digital camera enthusiast. LE provides the ideal file capacity for home systems: 10MB input and 64MB output.
**PrintPro 1.0 provides the same quality of encoding and decoding as the regular GF 2.0, but has special batch processing capabilities that are useful for high production shops and is the only version capable of handling CMYK and other color spaces besides RGB.
Does Genuine Fractals really perform as promised? We think it comes pretty close, and here are some test results to support our findings:
So as not to let the quality of the scanner be a factor in our comparisons, we chose to use a "vector" image file (from a royalty-free collection of clip art images by Aridi). Vector images are drawn on a path like type fonts, and can be scaled to any size and rasterized (turned into a bit mapped image, i.e. a TIFF) without any loss of quality whatsoever.
We chose the following EPS image, and rastered it in Photoshop to a size of 700 pixels by 700 pixels (shown here at 1/2 size). |  |
We then cropped the image down to this 255 pixels x 77 pixels section:
We then encoded the image file (more on this later) using Genuine Fractals (as a plug-in within Photoshop), producing a GF's ".stn" file. This encoded file, which even in its "lossless" version (no image quality loss due to encoding compression) is about 1/2 to 1/3 the size of the original Photoshop TIFF or Photoshop ".psd" version (the image must be flattened, however - no layers). We then opened the encoded GF ".stn" file in Photoshop. With the GF plug-in installed, Photoshop immediately recognizes the file and presents you with a pop-up window (more on this later) that asks you to what size you would like to "res-up" or enlarge (interpolate) the new output file.
For this test, we chose a file size that was 3 times (3X) larger than the original 255 x 77, or 765 x 231. GF also gives you the option to crop into the enlarged output file. For the sake of Web speed, we chose to crop in even closer on this first page (you can see the uncropped versions on this next page).
You may want to print these out (using a fine, photo quality setting) and view them side by side, so that the quality of your monitor is not affecting the comparison.
What you are going to see now are 4 versions for comparison:
- A "control" image that was rasterized from the vector clip art.
- A Genuine Fractals interpolated image (enlarged 3X).
- A Photoshop "nearest neighbor" interpolated image (enlarged 3X).
"Nearest neighbor" interpolation is what your printer would do to your image "on the fly", if you sent a small image file to it and asked it to enlarge the image -- the result can be quite "jaggy" or "pixelated".
- A Photoshop "bicubic" interpolated image (enlarged 3X).
"Bicubic" interpolation is Photoshop's best interpolation and its default. Bicubic smooths out the "jaggies", but softens the image as it enlarges.
1. Control image - rasterized from vector original | 
2. Genuine Fractals - enlarged 3X |
3. PS "Nearest Neighbor" - enlarged 3X | 
4. PS "Bicubic" - enlarged 3X |
CONCLUSION:
Genuine Fractals method of digital enlarging produces an image that is much sharper than Photoshop's standard "bicubic" method of interpolation. Although GF does not produce an enlarged image that is quite as sharp as an image scanned at the desired resolution, it appears to us to be at least 50% better than Photoshop's -- or a little better than half way between the best Photoshop interpolation results and a new higher resolution scan. Not bad!
Additional tests showed that GF is best when making "significant" enlargements to the original file. If your needed enlargement is less than 50% (enlarging the image to less than 1.5X), then the improvements afforded by GF will be hardly noticeable, and probably not worth the trouble. GF shines best when it is asked to enlarge an image two times (2X) or more.
NOTE: It should be noted that we're talking about doubling the image dimensions, not the file size -- a 2X image enlargement will actually quadruple the image's file size! Which points to another reason GF can be so valuable. Example: A file scanned to make an 8"x10" image @ 300 pixels per inch (ppi) would have an RGB file size of 20.6 megabytes. If you were to print the same image to 13"x19", you would need 63.6 megabyte file, if you wished to have the same 300 ppi resolution going to your printer. Having to rescan, retouch and re-manipulate a file that is over 3X larger can be a real hassle. GF makes for a very wise compromise in time savings verses acceptable quality. These same benefits can become even more significant if you are working with large-format printers, where file sizes can be in the hundreds of megabytes!
Click here to see learn more about how to use Genuine Fractals and to see uncropped versions of the above examples. (NOTE: be prepared for a bit of a wait as the JPEG images are compressed at a higher quality so compression artifacts do not play into the comparisons.)
Q and A:
Question:
Your test was with a high contrast drawing. When I tried it on a
photograph, I don't see much difference between Genuine Fractals and
bicubic interpolation. I have heard that it helps photographs if they
contain some high contrast objects. I'd like more discussions and
examples on using it with photographs. If it really worked, it would be
great for pictures taken with 2 and 3 megapixel digital cameras.
--Dewey
Answer:
Dewey,
Thanks for the feedback. Believe me, GF does work well on photographs (the "LE" $49.95 version of GF is made just for digital camera files up to 10 megabytes). These illustrations were not really high in contrast (no more contrasty than most photographs), but they did have a lot of definite or hard edges (higher contrast between adjacent pixels), and they had a lot of diagonal and curved lines -- which is where GF really shines. Regular interpolation (in Photoshop) has a real hard time keeping these areas sharp when it interpolates and enlarges the images. But GF maps these areas with a special algorithm that treats them almost as if they were a vector segment of the file (which can then be enlarges with almost no loss, like "res"-ing up a type font). In smooth or "bland" areas of a photographic image (low contrast between adjacent pixels), GF does no better than Photoshop interpolation in these areas. Examples would be sky, still water, lawns and meadows (without flowers), smooth flesh areas on people.
However, the eyes, eyelashes, nostril hole, mouth edges and teeth, hair detail, tree leaf and branch detail, flowers popping up in a meadow -- the list can go on and on....
....these areas greatly benefit from the GF technology.
One other thing that I failed to mention: There is something extra about GF in how it PRINTS. Some images don't seem that much different than Photoshop interpolation when you compare sections side by side at monitor (72 ppi) resolution, but when you PRINT the two files at normal printer resolutions (i.e. sending a 300 ppi file to a 1440 dpi printer), you notice a much greater difference. Somehow, GF just makes the TOTAL image work better at the printing stage. This is another reason we suggested that you print out the four test samples, especially the uncropped version. You may wish print a version at 1/2 sise by "reducing" the size of the printed page to 50% in your web browser (go: file menu / page setup / type in 50%, rather than the regular 100% default). This will send a file to your printer that has 144 pixels per inch, rather than the normal resolution of 72 ppi, like your monitor's resolution.
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