We have been talking about image resizing and how we should consider the image's content when we resize it. So, why on earth is it called seam carving? It should just be called content-aware image resizing, right? Well, there are many different terms that are used to describe this process, such as image retargeting, liquid scaling, seam carving, and so on. The reason it's called seam carving is because of the way we resize the image. The algorithm was proposed by Shai Avidan and Ariel Shamir. You can refer to the original paper at http://dl.acm.org/citation.cfm?id=1276390.

We know that the goal is to resize the given image and keep the interesting content intact. So, we do that by finding the paths of least importance in that image. These paths are called seams. Once we find these seams, we remove them from the image to obtain a rescaled image. This process of removing, or "carving", will eventually result in a resized image. This is the reason we call it "seam carving". Consider the image that follows:

In the preceding image, we can see how we can roughly divide the image into interesting and uninteresting parts. We need to make sure that our algorithm detects these uninteresting parts and removes them. Let's consider the ducks image and the constraints we have to work with. We need to keep the height constant. This means that we need to find vertical seams in the image and remove them. These seams start at the top and end at the bottom (or vice versa). If we were dealing with vertical resizing, then the seams would start on the left-hand side and end on the right. A vertical seam is just a bunch of connected pixels starting at the top row and ending at the last row in the image.