|
 |
Quick Find |
 |
|
|
|
Categories |
|
|
|
|
Information |
|
|
|
|
| 
Testing Genuine Fractals
Part 2 - a closer look
Return to Part 1
Your first step in using Genuine Fractals is to produce an encoded ".stn" file from the original digital image. Under the Photoshop "File" you choose "save as". With the GF plug-in properly installed you'll now have a choice of "Genuine Fractals" as a file format choice. Choose the "Genuine Fractals" file format, and you'll be presented with this pop-up menu:
Unless file compression (smaller file sizes) is more important to you than the upmost quality, alway choose "Lossless". Lossless will give you an encoded ".stn" file that is a digitally exact reproduction of the original, if the ".stn" file is decoded to the same size as the original. NOTE: If super compression is more important than being able to make sharp enlargements, then LizardTech's "MrSID" software would be a better choice for you. MrSID can compress a Photoshop file to less than 5% (20:1 encoding ratio) of its original size and still decode to a higher quality than a file that was given a 6:1 JPEG compression. (LizardTech is purchasing Altamira, the software company that produces GF.)
The next step is to decode the GF ".stn" file in Photoshop. Under the Photoshop "File" menu, choose "Open", then select the GF ".stn" file. You will then be presented with a GF menu like this one:
The top third of the menu shows your GF encoded file's original dimensions and file size (as well as its encoded or compressed file size). The middle part of the menu allows you to crop the image if you only need a portion of the image. (Although you can decode the whole file and crop it later in Photoshop, big enlargements can take several minutes to decode and scale, so doing a rough crop before decoding can greatly speed up the decoding process.) The bottom part of the menu allows you to choose the size you want to scale or enlarge the file to, and to choose the quality of the decoding. Allows choose the highest "Q1" quality of decoding, which takes longer, but is worth the wait.
As mentioned in Part 1, we chose an EPS (vector) clip art image, and rastored it in Photoshop to a size of 700 pixels by 700 pixels. We then cropped the image down to this 255 pixels x 77 pixels section:
We then encoded the image file using Genuine Fractals (as described above), 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 the pop-up window (describe above) that asks you to what size you would like to "res-up" or enlarge (scale) the new output file.
For this test, chose a file size that was 3 times (3X) larger than the original 255 x 77, or 765 x 231.
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.
Here are 4 versions for comparision:
1. Control image - rastorized from vector original
2. Genuine Fractals interpolated image (enlarged 3X dimensionally from the encoded ".stn: file).
3. 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.
4. 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".
CONCLUSION:
Genuine Fractals method of interpolation produces an images 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 al 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!
This info page sponsored by:
Inkjet Solutions for Photo-realistic and Fine Art Printing
Big savings on a
popular paper type
Are you currently using one of these inkjet papers?:
- Epson Premium Luster Photo Paper
- Ilford Galerie Smooth Pearl
- Lyson Professional Photo Satin
- Lumijet Genuine Pearl
...then basically, you've already used our Inkjetart Micro Ceramic Luster -- you just paid too much!
Save 30% to 50% on our Inkjetart Micro Ceramic Luster
|
|
|
Tracking
My Account
Cart Contents
Checkout
Home page
Forum
Contact us
Links
Newsletter
Finishing