How can I resize pictures changing the aspect ratio?

Question

Currently running Ubuntu 15.04. I am trying to resize a set of photos where the original size of each is 3906*2602.

Whether I try with darktable or mogrify specifying 1920*1080 I end up with 1621*1080.

For mogrify, I used the following specifications:

mogrify -path resized -quality 95 -resize 1920x1080 -strip '*.jpg'

There is obviously something I didn't get about picture resizing, but couldn't find any hint anywhere.

Would anyone know why it gets resized to 1621 instead of 1920?

Answer 1

As per Adonis' comment, the exclamation mark, ! forces mogrify to ignore the aspect ratio of the original image. so using 1920x1080! in the size parameter did the trick.