title: Perceptual coding of images for halftone display.
abstract: We present a new technique for coding gray-scale images for facsimile transmission and printing on a laser printer. We use a gray-scale image encoder so that it is only at the receiver that the image is converted to a binary pattern and printed. The conventional approach is to transmit the image in halftoned form, using entropy coding (e.g. CCITT Group 3 or JBIG). The main advantages of the new approach are that we can get higher compression rates and that the receiver can tune the halftoning process to the particular printer. We use a perceptually based subband coding approach. It uses a perceptual masking model that was empirically derived for printed images using a specific printer and halftoning technique. In particular, we used a 300 dots/inch write-black laser printer and a standard halftoning scheme ("classical") for that resolution. For nearly transparent coding of gray-scale images, the proposed technique requires lower rates than the standard facsimile techniques.
authors.affiliation: Dept. of Electr. Eng. and Comput. Sci., Michigan Univ., Ann Arbor, MI.
authors.forename: D I
authors.initials: DI
authors.lastname: Neuhoff
authors.forename: T N
authors.initials: TN
authors.lastname: Pappas