Hybrid Algorithms for Digital Halftoning and Their Application to Medical Imaging

Error di usion ordered dither and patterning are well known digital halftoning tech niques each with its advantages and disadvantages Error di usion is known for correlated artifacts looking like zebra stripes Images produced by ordered dither and patterning su er from arti cial contours in slowly varying regions of pictures Use of ordered matrices by both ordered dither and patterning results in poor rendition of small details so the images appear blurred We discuss how the modi ed Floyd Steinberg error di usion algorithm reduces correlated artifacts compared to the classical Floyd Steinberg algorithm without increase in the amount of work It also simpli es combining of error di usion with other methods We introduce two families of hybrid algorithms One of them combines the modi ed Floyd Steinberg algorithm with ordered dither and the other one combines it with patterning We ght the correlated artifacts with ordered matrices while reducing the accompanying arti cial contours by error di usion The latter achievement allows us to use smaller matrices and thus a ect small detail representation at low resolutions We show that hybrid algorithms are useful for digital simulation of classical screens Combining error di u sion and patterning results in speedups essential for printing medical images at high resolutions The article considers application of the hybrid algorithms to printing of medical images on laser