Source image:
Scaled wider and shorter:
Scaled narrower and taller:
Download the ImageJ macro here.Software used:
Image creation: ImageJ
From experimental art, photography and image generation to microscopy and science by Richard Wheeler. I run a research lab in the University of Oxford, with a focus on parasite cell biology, microscopes, and computational analysis.
The edge detection to find objects:
And 5 example low detail vertical "seams" which run through the image. These are the lines of boring pixels which will be removed to make the image narrower.
Removing 100 seams of pixels makes the image 100px narrower. See the following images for an example of the resizing in progress:

You can watch the scaling of four example images at YouTube.
Download the code for the ImageJ macro (used for rescaling of these images) here.