Patent ID: 6822751
Filing Date: 2004-11-23
Classification: G06K

Abstract:
A system for providing edge enhancement, with the system comprising:a printer engine producing multiple laser beams for marking a corresponding number of scan lines on at least one photosensitive medium; a window creator means for creating a corresponding number of windows each containing data of a matrix of dots centered at a to-be-processed dot located in a corresponding one of the scan lines; an edge enhancing device for providing edge enhancement for the windows; a multiplexer for alternately outputting the windows to the edge enhancing device; a plurality of modulators each adapted for controlling a corresponding one of the laser beams produced by the printer engine; and a de-multiplexer for alternately outputting the windows processed by the edge enhancing device to the modulators; wherein the edge enhancing device uses a method for enhancing a displayed image of a print or display apparatus, the method comprising the steps of: (a) generating a set of gradient masks each of which represents a plurality of edge segment transition conditions and includes a matrix of aÃ—b cells each cell of which is assigned a numerical weight corresponding to the relative lightness or darkness of the corresponding pixel of an image having an edge segment passing through a center pixel of the matrix; (b) generating a bit data signal including a plurality of data bits representative on a pixel by pixel basis of a bit map image to be printed or displayed; (c) storing in temporary storage means a predetermined number of consecutive bits in a predetermined number of consecutive lines of said bit map image; (d) selecting subsets of said bits forming a sample matrix of aÃ—b bits, the central bit of each sample matrix being a candidate for modification; (e) convolving each said sample matrix with each said gradient mask to detect those sample matrices having an edge segment passing through their central bit, said edge segment being defined as a series of adjacent aligned data bits of the same data state forming a straight line having a single slope, and to determine the direction of a gradient change; (f) generating a set of reference bit patterns each of which includes a sub-pattern of bits corresponding to one possible combination of bits of the same data state aligned in one or more edge segments, said pattern including an aÃ—b matrix of bits, a first predetermined number of bits disposed adjacent one side of said matrix, and a second predetermined number of bits disposed adjacent another side of said matrix; (g) comparing each said sample matrix having an edge segment passing through its central bit, a predetermined number of adjacent previously evaluated bits, and a predetermined number of adjacent yet to be evaluated bits to each pattern of at least a sub-set of said set of reference bit patterns; (h) generating for each match found to a reference pattern including a predetermined type of segment transition, a modification signal for modifying the central bit of said sample matrix dependent upon the type of transition detected; and (i) using said modification signal to cause the print or display apparatus to develop a corresponding output.