Method and Device for Mapping Input Grayscales into Output Luminance

摘要

A method for mapping an input grayscale into an output luminance includes selecting a first reference grayscale, a first reference luminance, a second reference grayscale and a second reference luminance according to an input grayscale, generating a middle reference grayscale and a middle luminance, replacing a value of the first or second reference grayscale by a value of the middle reference grayscale, and replacing a value of the first or second reference luminance by a value of the middle luminance according to the middle reference grayscale and the input grayscale, and generating an output luminance by computing a linear transformation equation.

主权项

1. A method for mapping an input grayscale into an output luminance comprising:
selecting a first reference grayscale, a first reference luminance, a second reference grayscale and a second reference luminance according to an input grayscale; generating a middle reference grayscale and a middle luminance by computing first and second equations of:
X_MID=(X1+X2)/2; andY_MID=(Y1+Y2)/2±Δ,wherein Δ denotes an offset, X1 denotes the first reference grayscale, X2 denotes the second reference grayscale, Y1 denotes the first reference luminance, Y2 denotes the second reference luminance, X_MID denotes the middle reference grayscale, and the Y_MID denotes the middle luminance;
replacing a value of the first or second reference grayscale by a value of the middle reference grayscale, and replacing a value of the first or second reference luminance by a value of the middle luminance according to the middle reference grayscale and the input grayscale; and generating an output luminance by computing a third equation of:
Y=Y1+(Y2−Y1)/(X2−X1)*(X−X1), wherein Y denotes the output luminance.