Rsizr is a website that offers access to a new technology for image resizing called “Seam Carving”. Seam carving has the potential to become a tool that will become an indispensable part of a graphic designer or web designer’s repertoire, and certainly we can see ourselves using this tool when designing a website, allowing us to have a greater flexibility choosing images for banners, sidebars and other areas of a website that, by their nature, have to be wide & short or tall & narrow.

Traditional Resizing vs Seam Carving

The traditional method of resizing an image requires you to either crop or squash the image.

Cropping the image is usually preferred as image proportions are kept the same and you discard some of the information from the edges of the image. However it can result in a sense that the photo is missing something, a fact that we attempt to turn to an advantage, but depending on the photo may not realistically be an option.

Squashing an image using a traditional resizing tool is usually avoided as it changes the proportions of an image and is usually only useful when a very small adjustment to the image size is required.

Seam Carving on the other hand works by analysing the content of your image and identifying “seams” which can be removed without dramatically altering the overall look of the image. In a sense, it is most like cropping the image, which means that the proportions are kept whilst you delete sections of the image.

To demonstrate this I have taken a suitable beautiful photo, taken by “es0teric” on Flickr. This is an image of Blood Falls, Dry Vall, Antarctica.

Demonstrating Rsizr’s Seam Carving Technology

Now the aim of this exercise is to make this image more useful as a panoramic image. Using traditional methods we would either crop or resize the image, the results of which are unsatisfactory. We want to take our image from 500px by 375px and reduce it to a height of 200px.

Using a standard resize tool we can squash the image. However, as you can see with the example on the right (click on the image to enlarge it), the image becomes completely disproportionate and looks, well, awful. The defined objects in this image - the tents - look flattened and unusual. In addition the background of the image looks stretched and out of shape.

Using a cropping tool, we get a better looking result, but due to the need to crop a large amount to reach our desired height of 200px, we have to remove quite a lot of the sky and mountains in the background of the image, thereby losing some of the sense of the place in which this photo has been taken.

Again you can see the result by clicking on the thumbnail.

Enter Rsizr

Using Rsizr’s simple web interface you can upload, edit and save your photo back to your computer. From the sounds of things, this new technology will likely be available in future versions of Photoshop seeing as the technology has been developed by one Adobe staff member and another scientist who has since been hired by Adobe. For those who like open-source alternatives, you’ll be happy to know that there’s already a plug-in for Gimp, the open-source competitor to Photoshop. However, for the purposes of this demonstration we’ll use the resizr website which is open to all (and free!).

Upload your image

Uploading your image is simple and straightforward.

Click “Open Picture” and browse to an image on your computer.

Rsizr then loads your image into its flash interface and you’re ready to carve some seams.

Protect certain areas of the image

An excellent part of this technology is that you can select areas of the photo that you need to prevent being touched in any way. This prevents an object or person in the photo from having seams removed. It can yield entertaining results though when used incorrectly).

In addition you can specify which areas of the image have a priority for removal. In this case, there are quite a few rocks in the foreground of the image that can definitely be removed.

Let Rsizr work its magic

Using the slider bars present above and to the left of the image, you can select how many pixels you would like to remove from the image. In this case we slide the vertical bar to 175px, giving us the option to resize this image to the desired 200px height.

Rsizr now calculates which areas of the image can be removed, quickly scanning through the image and ensuring that it avoids the areas you have protected and being ruthless with its carving of areas highlighted for removal.

Finish and Save

Finally, you use a standard tool to drag and resize your image, this allows you to see exactly what effect your resizing will have on the image, giving you the option to possibly choose to be less drastic in your resizing. In this case we can see that our mountain tops are preserved, and while we have lost some of the blue sky overhead, the effect is not nearly as dramatic as traditional cropping methods.

You can then save the image back to your computer, being careful not to save over the original of course.

The end result

Original Image:

Rsizr Image:

Traditional Resized Image:

Traditional Cropped Image: