Vectorscopes are a standard tool in professional video/film color
grading. *Very* simply, the Vectorscope shows image colors with hue as
the angle and saturation as the radius; brightness for each point in the
scope is determined by the number of "color vectors" at that point. More
specifically, the Vectorscope shows a 2D UV histogram of the image,
where U and V are the chroma ("color") channels of the image.
Co-authored-by: MacDue <macdue@dueutil.tech>
