Figure ground discrimination

In visual perception, figure-ground refers to humans' ability to separate elements based upon contrast. The principle of figure/ground is one of the most basic laws of perception and one that is used extensively to help artists and designers in composition of a 2D piece. In its basic sense, it refers to a cognitive ability to separate elements based upon contrast, that is, dark and light, black and white. Many times this definition is expanded from a simple perception based on contrast to include abstract concepts such as subject/background and positive/negative space.

The famous optical illusion image depicting both a vase and two profiles of a human face is often used to illustrate the concept of figure ground: Depending on whether the white or black color is seen as the figure (forefront) or the ground (background) the brain will interpret the picture as two different images, and it may be difficult to perceive both meaningful images simultaneously.