Abstract: A method of generating an output device control signal having portions representing the content of pixels of an image including at least two types of image content, in which data defining the content of each pixel of the image at a lower, first resolution and a higher, second resolution are passed respectively through a pair of processing paths, one corresponding to each image content type. A binary control signal is generated from the first resolution data in the first path by applying a stochastic screen. The binary control signal resulting from the stochastic screen is adapted to conform with the data at the second resolution, and the output device control signal is generated by combining data from the two processing paths.

Abstract: A method and apparatus for generating a representation of a half-tone image including areas of different resolution. The apparatus comprises stores (2, 26) for storing digital color data representing color density information at low and high resolution respectively. A second store (25) stores spatial data indicating the type of image data to be used at each position on a record medium (7). A third store (2') is provided for storing half-tone dot information. A group of six light modulators (10) which generate six scanning beams are arranged side-by-side. A support (8) supporting the record medium (7) to be exposed to the scanning beams is provided while drive motors (6',9') cause relative movement between the support and the scanning beam.

Abstract: Method and apparatus for generating a half-tone dot representation of an original image which has been previously generated as one or more color separations each comprising a plurality of cells (12), each cell being digitally encoded in accordance with the color density at that point is described. The apparatus comprises a record medium support (8); a plurality of scanning beam generators arranged side by side, the scanning beams (B1-6) and the record medium support (8) being relatively movable. First control means controls the scanning beams during relative movement between the scanning beams and the record medium support (8) in response to the digital information and half-tone dot information to generate a plurality of half-tone dots (14) at a first rate, each dot corresponding to one or more of the plurality of cells (12).