Method and device for mapping input grayscales into output luminance

A device for mapping an input grayscale into an output luminance comprising:

• a lookup table unit, for storing a plurality of reference grayscales corresponding to a plurality of reference luminance, respectively;
• and
• a logic unit, coupled to the lookup table unit, for selecting a first reference grayscale, a first reference luminance, a second reference grayscale and a second reference luminance according to an input grayscale to generate a middle reference grayscale and a middle luminance by computing first and second equations of:
• X_MID=(X1+X2)/2;
• and
• Y_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 to generate an output luminance by computing a third equation of:
• Y=Y1+(Y2−Y1)/(X2−X1)*(X−X1), wherein Y denotes the output luminance.

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;
• and
• generating an output luminance by computing a first equation of:
• Y=Y1+(Y2−Y1)/(X2−X1)*(X−X1),
• wherein Y denotes the output luminance, 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;
• and
• generating a compensated luminance according to the output luminance, at least one slope compensating values, and the input grayscale, wherein the compensated luminance is generated by computing a second equation of:
• Y_CP=Y+Y_OFS, wherein Y_CP denotes the compensated luminance, and Y_OFS denotes an offset luminance.

A device for mapping an input grayscale into an output luminance comprising:

• a lookup table unit, for storing a plurality of reference grayscales corresponding to a plurality of reference luminance, and a plurality of slope compensating values;
• a logic unit, coupled to the lookup table unit for selecting a first reference grayscale, a first reference luminance, a second reference grayscale and a second reference luminance according to an input grayscale to generate an output luminance by computing a first equation of:
• Y=Y1+(Y2−Y1)/(X2−X1)*(X−X1),
• wherein Y denotes the output luminance, 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;
• and
• a compensating unit, coupled to the logic unit and the lookup table unit, for generating a compensated luminance according to the output luminance, at least one slope compensating values, and the input grayscale, wherein the compensated luminance is generated by computing a second equation of:
• Y_CP=Y+Y_OFS, wherein Y_CP denotes the compensated luminance, and Y_OFS denotes an offset luminance.