by Dan Delong
From the author: "This software implements an alternative image upscaling technology. You can use it to increase the resolution of your images, or details taken from them... the benefit of the algorithm depends on the quality and the special characteristics of the image."
After using this program to enlarge a few sample digital images, I feel it has proven itself, by providing better quality results than simply upscaling / enlarging / resizing with a photo editor. Depending on the hue range of adjacent pixels, results may be subtle or more obvious. PhotoShop's "Preserve Details" enlarger came very close in most cases. But, PhotoShop is both expensive and requires a lot of hard drive space.
Figure 1 Screen grab of original - not yet upscaled
Let's say you have a photo of a building, taken from ground level, and you find the perspective needs correction, or the horizon is not straight, and you wish to level the horizon line. Your chosen editing software will perform this action, by analysing each pixel and relocating it in the frame, using a couple of interpolation routines; either Bicubic or Bilinear. The areas of the photo needing the greatest adjustments will degrade in quality. However, if the image is first upscaled, using the A Sharper Scaling program - perhaps by 200% - then, corrected for perspective, followed by downscaling to the original dimensions, the results will be much better.
Figure 2 at 400% upscaling - Bicubic method compared to A Sharper Scaling
Scaling Factor: 50% to 400%
Figure 3 Smilla Enlarger alternative at 400% - program may no longer be available
Smilla Enlarger is an upscaling program that I have used in the past. It has a wide range of smoothing options. A Sharper Scaling does a better job of maintaining pixel integrity, and should be used prior to a smoother, like Smilla Enlarger.
The sample images in this document may not show the true effects of enlarging because browsers perform their own resizing algorithms. Go to the download page for a full explanation by the author, and examples of his methods.
Platform: Windows all - needs .NET 3.5 for Vista
Version: version 1.1 as of November 2016
Download Size: 639 KB
Installed Size: 1.3 MB
Download Site: here.