A number of old favorite Photoshop plug-ins by different manufactures are now under the label of onOne Software. The two programs I am reviewing are Genuine Fractals Print Pro 4.1 and pxl SmartScale 1.0. They are both Photoshop only plug-ins and both are supported by Photoshop CS and CS2. Why should one use either of these programs and not simply Photoshop to increase the size of an image?
I have written articles on interpolation and resampling. In brief, sampling up means adding pixels and sampling down means deleting pixels from an image. All involve degrees of guesswork usually by the use of mathematical formulae.
Photoshop's best method is Bicubic. This method is based on an examination and calculation of the values surrounding each pixel. Each time you increase the pixels, you do this step again and again using the new pixels in the same manner. As you can see, this can lead to complications and potential problems with color accuracy.
Genuine Fractals 4.1 (GF) tries to avoid this pitfall by sampling 16 pixels that surround each target pixel. In brief and not scientifically, GF uses what the image used to look like with what it presently looks like and applies that knowledge to what one wants it to look like in the future (its new size). It does this by downsampling by 50% and comparing it to the original so it can use that information over the pixel blocks of the image. It then upsamples by a factor of two (100%>200%>400%etc) and feeds the scaled image back into the algorithm.
The other scaling product, pxl SmartScale 1.0, examines the image and calculates a mask where the edges of the image are. It, then, scales the image and ensures that the edges are sharp. It has a number of controls that deal with edges. Genuine Fractals Print Pro 4.1 differs from Genuine Fractals 4.1 in the fact that it can deal with CMYK images and CIE-Lab images as well as RGB images. Genuine Fractals 4.1 can only deal with RGB images. Both Genuine Fractals 4.1 and Genuine Fractals Print Pro 4.1 have the characteristics as described below.
The other scaling software, pxl SmartScale, has a different function.
Genuine Fractals 4.1 and Genuine Fractals Print Pro 4.1 differ from pxl Smartscale according to the company in that both version of GF are used best in natural images, landscapes, and portraits while pxl SmartScale is best employed where edges are well defines and hard, and keeping them that way is important.
In this review I will test both products using various images. First, I cropped an image of myself taken with a digital camera. Without any type of resampling, the head part was about 1.25" x 1" at 300 dpi. I, then, enlarged that head by 500% and, then, starting fresh from the 1" original, I enlarged it again by 800%. I put these on an 19" x 13" piece of Lustre paper using my Epson Stylus Photo R2400 printer and printed it from CS2, using specific profiles and the Best Photo setting. Do not judge by the image below; it was reduced many times to fit the review. I did both the 500% and the 800% enlargements in Photoshop CS2 using the Bicubic method and in Photoshop CS2 using Genuine Fractal Print Pro 4.1.
The results were more pronounced in the 800% resampling. It was very good in Genuine Fractals Print Pro 4.1 and good in Photoshop CS2. The image was crisper as a whole in GF and the catch light in the eyes was much crisper in GF.
The differences in the 500% resampling were not as obvious. The catch light was still crisper in GF, but Photoshop CS2 did a good job of resampling just using the Bicubic setting. I showed the collage to a number of people and they all chose the Genuine Fractal Print Pro 4.1 images. The unanimous consensus was that the fine details were sharper when enlarged using Genuine Fractals Print Pro 4.1 although at 500%, as I stated, Photoshop did a good job.
For my next test, I took an image I had created in Vue 5 Infinite that included an Xfrog 3.5 Willow tree version2 and a Poser 5 person. I tested it in the same manner as I did the image above.
The results of the tests were similar, however, there were small differences. There was more of a noticeable difference in the leaves between all the 500% and 800% resampled images when seen with a magnifier. There was a hint of blurriness with the 800% resampled images. The details of the Poser image were better in the Genuine Fractals Print Pro 4.1 image even without a magnifier when comparing the 500% Photoshop CS2 Bicubic resampled image with the Genuine Fractals Print Pro 4.1 resampled image. The same held true for the 800% resampled images.
In older versions of GF, the images had to be saved in the STN format. While this was useful for it cut down on the size of resampled images (sampled up), it could also be cumbersome each time that image had to be used. Now one has the option of converting a PSD file, for example, to a STN file.
Pxl SmartScale is a different type of scaling plug-in. It is versatile in that you can control how the edges in the image look - contrast and sharpness and how the whole image looks from the gamut of sharpest to smoothest. It works on analyzing and storing the brightness and color of an image and generating an equation for scaling from that information. It works in either CMYK, RGB, grayscale and in 8-bit.
Above is an example of the types of categories one has in order to control how the image will look when scaled. In Overall Sharpness, there are four choices - Sharp, Normal, Smooth, and Smoother. Edge Contrast and Edge Detail have a high and a low setting. A good illustration of this can be seen on a posterized image that I created.
Edge Detail will also change; however, the screen shot did not show it well enough to show it here.
The Extreme Edge Setting can be turned off and on. This setting is used mainly for illustrations and computer generated work according to the quick movie on onOne Software's web site. There are short QuickTime movies about all the products.
I found that the Overall Sharpness on my tests did not have too much of an affect. The biggest affect was caused by turning off or on the Extreme Edge setting. With the setting on, a posterization effect happened.
The following shows it even more so. It is an interesting effect even though it is a byproduct of the plug-in. Below, are pieces of two autumn leaves touching each other.
I agree with onOne Software when they stated that this filter was not as good as Genuine Fractals for natural scenes. I tried it with the same scenes as I did Genuine Fractals, and while it did produce decent resampled images, they were not as good as Genuine Fractals. In addition, at 1200% and above, they were very soft.
I still really like Genuine Fractals and how it has evolved over the years. I find that Genuine Fractals Print Pro 4.1 did a little better in preserving fine details than did resampling in Photoshop CS2. I did a comparison test between Genuine Fractals Print Pro 4.0 and 4.1 using Photoshop CS2 scaling the image by 600% and I think, although it was very close, that the image enlarged in Genuine Fractals Print Pro 4.1 had a little more detail than did the one enlarged using version 4.0. I think either version of Genuine Fractals is more versatile than pxl SmartScale unless one has a specific reason for purchasing the latter. However, pxl SmartScale performed according to specifications.
Test these two programs out yourself. All have 30 day trials. I find that I use Genuine Fractals a lot when rendering. I will render a smaller image than I eventually want, but make sure that I have enough detail in the image. Then, after doing post work on it in Photoshop, I increase the size before I print it. I usually print on a 13" x 19" sheet and have looked at details with a magnifier. So far I have been very satisfied with the results.
The Paula Sanders Report is a regular Renderosity Front Page featured column, where Paula investigates and comments on graphic software, techniques, and other relevant material through her reviews, tutorials, and general articles.
January 2, 2006