Methods for characterizing CRT displays

Computer-controlled CRT displays can be described by a two-stage model. The first stage consists of a linear transformation matrix relating radiometric scalars of each channel with either spectral radiance or tristimulus values. The second stage is nonlinear and relates digital counts with the radiometric scalars for each channel. The term system gamma, Gamma, is introduced to define the non-linear stage. Gamma can be characterized by either direct measurement or using a theoretical model with gain, k(g), offset, k(o), and exponential, gamma, parameters. Techniques and recommendations are given both to determine the transformation matrix coefficients and estimate Gamma using several methods. Special attention is given to Macintosh imaging systems. Key issues include channel and spatial independence tests, including optical flare due to internal reflections, and problems arising from preset video look-up table entries.