I recently had a chance to ask Graeme Frost of Grasshopper Limited (makers of ImageAlign™) a couple of questions about Grasshopper and ImageAlign™. ImageAlign™ is the Premiere Sponsor of our 2006 Photograph of the Year contest, and if you haven’t had a chance to check out the software, make sure you drop by and try the free trial.

Tell me a little bit more about Grasshopper and ImageAlign™.

Grasshopper was formed to develop and commercialize an ‘idea’ that became ImageAlign™. Initially focused on perspective distortion correction, the ‘idea’ came from an non photographer, non software developer who was bedridden for several months after an accident. He became fascinated by the perspective distortion in a landscape photograph and over time thought through the ‘mathematics’ of fixing it. Once that was developed into working software, barrel distortion correction, skew correction and rotation were added.

Now ImageAlign™ basically is distortion correction software, used to correct barrel and perspective distortion. Can you describe what causes this distortion, and why it’s important to correct it?

The causes of the two types of distortion are quite different. Perspective distortion happens when you photograph a subject with vertical or horizontal lines and you don’t have the film plane perfectly perpendicular to the centre of the subject. The effect of it is that perpendicular lines appear to be converging, and the objects seem to lean away from or towards you. These are possibly the most difficult photographic distortions to rectify, and yet there are so many situations where you just cannot place the camera in the right spot to avoid this! Expensive tilt-shift or rectilinear lens to a large extent also solve the problem, but even then, the camera position has to be perfect. ImageAlign™ fixes Vertical and Horizontal perspectives.

Barrel distortion occurs when you use a fish-eye or other wide-angle lens. The lens rounds the image as if it was on a ball. ImageAlign™ fixes this, effectively flattening out the image.

How does ImageAlign™ correct these distortions?

ImageAlign’s algorithms were developed to reverse the effect of the bending of light that caused the distortion in the first place. It has sliders for each distortion correction that can be operated independently or together - allowing the user to correct multiple problems at the same time – and see the effect of each adjustment of the other.

What other benefits does ImageAlign™ provide to the amateur and professional photographer?

As well as been able to correct barrel and lenses distortion, ImageAlign™ can correct skew and rotation. It can resize the image to eliminate ‘white space’ when a correction is complete.

There is a Home version of ImageAlign™ and a Pro version. What are the differences between the two?

Home edition doesn’t include barrel correction, is only supported on PC’s (ie not on mac), does not act a photoshop plugin and is limited to Images of 5MB.

To download a free trial version of ImageAlign™, visit http://www.imagealign.com/demo.asp.