”We propose a simple image operator, we term seam-carving, that can change the size of an image by gracefully carving-out OR INSERTING pixels in different parts of the image”
That paper (which I think is the paper introducing the seam carving technique) also has examples of widening pictures.
https://perso.crans.org/frenoy/matlab2012/seamcarving.pdf (emphasis added):
”We propose a simple image operator, we term seam-carving, that can change the size of an image by gracefully carving-out OR INSERTING pixels in different parts of the image”
That paper (which I think is the paper introducing the seam carving technique) also has examples of widening pictures.