Patent ID: 8560585

Claim:
A method for generating a tonal-reproduction-curve for a printing apparatus by combining digital lookup tables comprising: converting, using a processor, the values in a first lookup table from integer to a first set of floating point values the floating point values representing a function of an input variable; filtering, using an electronic circuit, the first set of floating point values to reduce quantization errors; converting, using the processor, the values in a second lookup table from integer to a second set of floating point values, the floating point values representing a function of an input variable; filtering, using the electronic circuit, the second set of floating point values to reduce quantization errors; applying a standard sequence of values as input to the function represented by the first set of filtered floating point values to generate a first transformed standard sequence; applying the first transformed standard sequence as input to the function represented by the second set of filtered floating point values to generate a second transformed standard sequence; quantizing the second transformed standard sequence to generate a combined lookup table; and storing, in an electronic memory, the combined lookup table as the tonal-reproduction-curve for the printing apparatus.