Ciaran McNulty

Sometimes it's useful to be able to change the shape of a photo - on our website PropertyMall, we like the thumbnails on our property search results to be a nice uniform size. Rather than stretch the images, we've chosen on that site to crop them down to the correct size, however this approach can sometimes have odd results.

I've just been looking at the Liquid Rescale plugin for GIMP, which attempts to let you rescale images to different aspect ratios without having to distort or crop out the important details. The technology used is Seam Carving, which you can read about in this paper by Shai Avidan and Ariel Shamir, or watch a video about it on Youtube.

As an example, imagine I had a system that only accepted square images. Here is a picture I took a while back of some elephants:

16th April 2009, 13:23 (tags: photography ) Read more »

Arthur C Clarke once said that any sufficiently advanced technology is indistinguishable from magic. I always knew that some day something would come along that my brain just couldn't comprehend, I didn't realise that would happen before I was thirty.

Stitching panoramas together is something we've all tried to do. I've in the past spent some unproductive hours in Photoshop trying to scale, skew and match snaps together myself. I've also spent hours adding 'control points' to images in various shareware applications, all with middling results.

However, I appear to have been missing out on a big revolution. Nearly five years ago M. Brown and D. G. Lowe presented a very interesting paper that you can read here (PDF). They came up with an algorithm called 'Autostitch' that had some interesting properties - given a large set of photos it can identify which of them have common features and stitch them together on its own - without any user input at all!

Frankly I was suspicious that it would work, but I gamely downloaded the demo of Calico, a Mac app that implements Autostitch.

13th June 2008, 20:04 (tags: photography ) Read more »