Resize image with mogrify without keeping aspect ratio

After another half hour of searching I have stumbled upon the overly simple answer. The following will resize an image with the exact dimensions given:

mogrify input.png -resize 256x256! output.png

If you want to read more about it, I got the answer from this link:

https://superuser.com/questions/212752/how-to-stretch-an-image-in-one-dimension

use "!" in convert -resize, for ex:

convert "from-img"  -resize 800x480! "to-img"