Fast and Adaptive Color-to-Grayscale Conversion (sketches 0223)

Despite the widespread availability of color cameras and color displays, there is still a demand for black-and-white imagery due to three main factors: (1) artistic effects (e.g. Ansel Adams), (2) the cost gap between color and black-and-white printing, and (3) the design of many algorithms in image processing and computer vision that require a single value per pixel. Recent research [Rasche et al. 2005; Gooch et al. 2005] has focused on constraining the mapping of colors to grayscale values based on an image’s color content to produce good results with few parameters. Both groups tried to preserve the original distances between colors after they have been mapped to grayscale values.