Picture function
Encyclopedia
A picture function is a mathematical representation of a two-dimensional image as a function
of two spatial variables. The function f(x,y) describes the intensity of the point at coordinates (x,y).
Function (mathematics)
In mathematics, a function associates one quantity, the argument of the function, also known as the input, with another quantity, the value of the function, also known as the output. A function assigns exactly one output to each input. The argument and the value may be real numbers, but they can...
of two spatial variables. The function f(x,y) describes the intensity of the point at coordinates (x,y).