Patent ID: 7328116

Claim:
For a display monitor subject to a power law equation L=(αD+β) γ +φ, where: L=output luminance; D=input digital gray level; α=gain; β=offset; φ=external light flare; and γ=gamma, a method for deriving gamma based upon visual output of the display, the method comprising: displaying test pattern to a user on the display monitor, the test pattern comprising at least one of: a pattern of alternating light and dark regions displayed to the user at different gamma correction levels; a grayscale character string displayed to the user at different digital gray levels against a background of two known luminance levels; receiving input from a user as to at least one of: (i) a gamma correction level that results in the pattern of alternating light and dark regions having light and dark regions of perceived equal size as viewed on the display monitor and judged by said user; and, (ii) a luminance level for the grayscale character string that results in the user perceiving maximum readability of the grayscale character string relative to the two known background luminance levels as viewed on the display monitor and judged by said user; and, deriving gamma for the display monitor based upon the user input and using the derived gamma value according to said power law equation to calibrate the display monitor and thus adjust the output luminance (L) of the display monitor for given input digital gray levels (D).