Is this research not stating the obvious? As a painter I would differentiate background from foreground by decreasing its saturation, lightness and hue local c

Is this research not stating the obvious? As a painter I would differentiate background from foreground by decreasing its saturation, lightness and hue local contrast, softening edges, decreasing neighboring regional contrast and Lessing its average color values in relation to the foreground. Painters have been doing this for hundreds of years.