Depiction is reference conveyed through pictures. Basically a picture refers to its object through a non-linguistic two-dimensional scheme. A picture is not writing or notation. A depictive two-dimensional scheme is called a picture plane and may be constructed according to descriptive geometry where they are usually divided between projections and perspectives. Pictures are made with various materials and techniques, such as painting, drawing, or prints mosaics, tapestries, stained glass, and collages of unusual and disparate elements. Occasionally, picture-like features may be recognised in simple inkblots, accidental stains, peculiar clouds or a glimpse of the moon, but these are special cases, and it is controversial whether they count as genuine instances of depiction. Similarly, sculpture and theatrical performances are sometimes said to depict, but this requires a broad understanding of 'depict', as simply designating a form of representation that is not linguistic or notational. The bulk of studies of depiction however deal only with pictures. While sculpture and performance clearly represent or refer, they do not strictly picture their objects.
