anamorphical widescreen
Anamorphical Widescreen is a compression method for displaying widescreen footage with an aspect ratio of 1.78:1 (16:9) and Panavision footage with an aspect ratio of 2.35:1 on displays with an aspect ratio of 4:3 and Panavision footage on displays with a widescreen display of 16:9.
Anamorphic Widescreen prevents the black bars at the top and bottom of the screen by compressing the image format horizontally when it is stored on DVD-Video and decompressing it when it is displayed.
The displayed image has the full number of lines, but is distorted horizontally. A 16:9 format, displayed in 4:3 aspect ratio, experiences a horizontal compression.