2D to 3D conversion into account that more distant objects, besides being hazy, should be more desaturated and more bluish because of a thick air layer. The idea of the method is based on the fact that parallel lines, such as railroad tracks and roadsides, appear to converge with distance, eventually reaching a vanishing point at the horizon. Finding this vanishing point gives the farthest point of the whole image. The more the lines converge, the farther away they appear to be. So, for depth map, the area between two neighboring vanishing lines can be approximated with a gradient plane. 2D to 3D conversion
Horizon the distance, stimulated the development of projective geometry which posits a point at infinity where parallel lines meet. In her book "Geometry of an Art" (2007), Kirsti Andersen described the evolution of perspective drawing and science up to 1800, noting that vanishing points need not be on the horizon. In a chapter titled "Horizon", John Stillwell recounted how projective geometry has led to incidence geometry, the modern abstract study of line intersection. Stillwell also ventured into foundations of mathematics in a section titled "What are the Laws of Algebra ?" The "algebra of points", originally given by Karl von Staudt