The aspect ratio of an image describes the proportional
relationship between its width and its height.
It is commonly expressed as two numbers separated by a colon, as in 16:9.
For an x:y aspect ratio, no matter how big or small the
image is, if the width is divided into x units of equal length and the height
is measured using this same length unit, the height will be measured to be y
units.
Some common aspect ratios
