This page is a part of CVprimer.com, a wiki devoted to computer vision. It focuses on low level computer vision, digital image analysis, and applications. It is designed as an online textbook but the exposition is informal. It geared towards software developers, especially beginners, and CS students. The wiki contains mathematics, algorithms, code examples, source code, compiled software, and some discussion. If you have any questions or suggestions, please contact me directly.

From Computer Vision Primer

It is a function from the rectangle (in 2D) to the parameter space which is usually an array.

Parameter spaces:

• Binary Images: {0,1} (1 parameter)
• Gray scale images: {0,...,255} (1 parameter)
• Color Images: {0,...,255} x {0,...,255} x {0,...,255} (3 parameters)

For videos add another parameter (time).

Also "Almost all physical units can be used to make images and multivariate images: temperature, gravitational field, impedance, magnetic field, electrical field, mass, wavelength, ultrasound wavelength, polarization, electron energy etc." [1].