Patent Number: 6,295,137

Title: Method of color correction using multi-level halftoning

Abstract: A method is proposed for reducing the cost of color transformations implemented by multi-dimensional lookup tables, especially in the case where the input space is a luminance-chrominance color space. Multilevel halftoning is applied to the two chrominance coordinates in order to map them to the chrominance node values of the lookup table. Multilevel chrominance halftoning introduces chrominance errors at high spatial frequencies, where the human visual system is insensitive. 1-D interpolation is then applied on the luminance coordinate to obtain the output color value. This method therefore reduces 3-D interpolation to halftoning and 1-D interpolation, thereby saving computational cost without introducing objectionable image error.

Inventors: Balasubramanian; Thyagarajan (Webster, NY)

Assignee: Xerox Corporation

International Classification: H04N 1/60 (20060101); H04N 001/40 ()

Expiration Date: 09/25/2018