Abstract: A printing apparatus operatively connectable to a mounting arm that comprises an interchangeable pallet unit with a longitudinal axis and operatively connectable to the mounting arm for movement along the longitudinal axis, an indexing mechanism operatively connected to the interchangeable pallet so as to permit the interchangeable pallet indexed movement in a direction transverse to said longitudinal axis, and a bar unit operatively connectable to the mounting arm configured to receive a printing screen.

Abstract: A technique for developing an analytic model of an image by operating directly upon the pixel map representation output by an optical sampling device, such as a scanner. The resulting analytic representation is hierarchical, below a certain level, with each element an analytic expression representing a portion of the image. Above a certain level, the model is a simple array, to facilitate certain types of graphical manipulations. The model is developed by arranging pixel values into a number of groups called tiles. A number of operations are then performed on each tile, to determine how it can best be represented as an analytic expression. For example, if all pixel values in a tile are approximately continuously varying, they be represented as a three-dimensional linearly sloped surface. However, if one or more intensity boundaries run through the tile, analytic expressions, such as a straight line or a parabolic line segment, are derived from the tile's pixel values to describe the edges.

Abstract: A technique for creating and applying half tone screen patterns by computer, consisting of a screen generator and a screen applicator. The screen generator accepts a set of parameters specifying the angle and frequency of the desired screen, the output printing device resolution, and parameter tolerances. It then produces a half tone screen pattern file according to the specified parameters, as a set of repeat arrays for each desired gray level. The screen applicator accepts an input contone image representation such as is produced by a scanner or other device, and the half tone screen pattern file produced by the screen generator. It then interpolates between the pixel values, at the output device resolution, by examining the repeat arrays for each device cell. In this way, a representation of a half tone screening of the input contone image results where the output device resolution is fully exploited.