Introduction - If you have any usage issues, please Google them yourself
With R, G, B axis to build the space right angle coordinate system, then each pixel of RGB graph colors can be used for a point in the three-dimensional space to represent,
Each pixel of Gray graph colors can be used for a linear R=G=B to indicate. The essence and RGB transgenic gray map is looking for
The mapping of one dimensional space into a three-dimensional space, the most easy to think of is projective (a point that RGB space to do a line perpendicular to the line R=G=B)