Image Retargetter is a bit of software I wrote after being blown away by Dr Ariel Shamir's and Dr Shai Avidan's presentation from the SIGGRAPH2007 conference entitled "Content Aware Image Resizing".

Their idea involves calculating arbitrary "seams" of "least interest" that cross an image and then either removing or doubling those seams. The effect is that you can change the width or height (and therefore the aspect ratio) of an image without distorting the image's subject. Sounds bonkers, but it works. How well it works depends on the source image: some are ideal, others can't be retargetted at all.

The program features a huge range of pre- and post-processing options and a number of seam computation methods to provide the best possible change of acheiving a workable retargetting of any image.

So the challenge with the interface was to model a potentially rather confusing process with a great deal of complexity and flexibility into a layout that folks would find easy to use and understand.

The result uses a sleek graphite theme similar to PSPX2. The interface features a large context-aware HTML help panel which constantly updates as the user progresses through the steps of the retargetting process; various accessible view modes and zoom options including a contant-best-zoom mode which continuously updates as the image is resized to ensure the best zoom level is maintained; a straightforward slider bar for resizing; and models the retargetting process by breaking it down into five distinct, sequential stages and grouping their relevant interface components in an intuitive, readable, left-to-right layout.

You can see some results of the program, including an interactive demo of a context-aware-self-resizing image on the applications homepage, here.

The image here shows the retargetter's analysis of an image of horseriders on a beach. The blue lines indicate seams that can best be added or removed without distorting the image, the green areas guide the seams' paths and red pixels generally cluster around sensitive parts of the image which the seams should avoid. Resizing this image horizontally with the retargetter would create/reduce space between the riders (just like using crop/clone in PSP, but totally automated and instant) without distorting the shapes of the horses or their riders.