Before we start our discussion about seam carving, we need to understand why it is needed in the first place. Why should we care about the image content? Why can't we just resize the given image and move on with our lives? Well, to answer that question, let's consider the following image:

Now, let's say we want to reduce the width of this image while keeping the height constant. If you do that, it will look something like this:

As you can see, the ducks in the image look skewed, and there's degradation in the overall quality of the image. Intuitively speaking, we can say that the ducks are the "interesting" parts in the image. So when we resize it, we want the ducks to be intact. This is where seam carving comes into the picture. Using seam carving, we can detect these interesting regions and make sure they don't get degraded.