Hewlett-packard Company

Hewlett-packard Development Company, L.P.

Jeff H Papke

Timothy P Blair

Russell Campbell

Dellas G Frederiksen

Richard M Dow

Douglas J Mellor

Steven J Claiborne

Roger T Baird

Richard Detweiler

Charles K Keyes

Gregg S Goyins

Methods of providing page protection in digital printing systems having multiple output devices are described. In one embodiment, first and second output devices are provided and have different time constraints for processing predetermined amounts of data which will ultimately be printed on a print medium. One of the time constraints is selected to provide a selected time constraint, and at least one predetermined amount of data is tested against the selected time constraint to determine whether the selected time constraint is satisfied. If the selected time constraint is not satisfied, the predetermined amount of data is transformed into a state which is more likely to satisfy the selected time constraint. In another embodiment, a first processing time constraint of a first output device is determined. The first processing time constraint impacts the manner in which a predetermined amount of data is processed into a printed image. A second processing time constraint of a second output device is determined. The second processing time constraint impacts the manner in which the predetermined amount of data is processed into a printed image. The first and second processing time constraints are compared and responsive to the comparison, the processing time constraint having a lesser magnitude is selected to provide a selected processing time constraint.

Methods of providing page protection in a digital printing system having multiple output devices

There is described a method for determining the relative location between a rectangle and a polygon. First, a box that bounds the polygon is created. An outside indicator is returned if the rectangle is outside the box. An intersect indicator is returned if the box is entirely inside the rectangle. If an odd/even fill process is in use then first the intersect indicator is returned if the rectangle intersects with the polygon or if a subpath bounding box is entirely inside the rectangle. Finally, if the location of the rectangle has not yet been returned, the location of a single point of the rectangle is returned. If a non-zero winding fill process is in use, first, the intersect indicator is returned if at least one corner of the rectangle is in a different side of the polygon than remaining corners of the rectangle. Next, the intersect indictor is returned if an edge of the rectangle starts outside the polygon and intersects with the polygon or if an edge of the rectangle intersects with the polygon and transitions outside the polygon. A subpath bounding box that bounds any subpaths is created. The location of a corner of the rectangle is returned if a point inside the subpath is equal to the corner of the rectangle. In the alternative, where the corner and subpath's points are different, the intersect indicator is returned. Finally, if the location of the rectangle has not yet been returned, the location of a center point of the rectangle is returned.

Detecting insideness of a rectangle to an arbitrary polygon

An imaging subsystem for a printer is configured to support multiple printer personalities. The imaging subsystem has an integrated display list that is accessed and used by all of the printer personalities. The printer implements a display list builder tool that assists each personality in posting its objects to the display list.

Integrated display list and building tool for multiple personalities

A method for undercolor removal (UCR) from a multi-color image represented by N color planes of non-black pixel image color values and replacement of removed undercolor by black values, includes the following steps. A corrected black color plane is obtained by replacing initial maximum black color values with black color values that are a Min function between the initial black color values and N-1 logically corresponding non-black pixel image color values. Page strip portions of the corrected black color plane are then revised so that each pixel black color value thereof is converted to a UCR value by deriving the Min function with logically corresponding, Nth color plane non-black pixel image color values. Next, logically corresponding UCR values for each page strip are subtracted from Nth color plane non-black pixel image color values and each page strip from the Nth color plane is passed to a print engine for rendering. Next, logically corresponding UCR values for each page strip are subtracted from the remaining ones of the N-1 color plane non-black pixel image color values. The N-1 color plane page strips are then fed to the print engine. The UCR values from the black color plane are then used for GCR.

Method and apparatus for undercolor removal during page pipeline

A data processing system that prints characters using a raster-scan pixel representation employs an inversion technique to achieve the filling of interior pixels within a polygon. At intersections of segments that define edges of the polygon, a common pixel may be shared by the last pixel of a first line segment and a first pixel of a second line segment. The inversion action is inhibited when considering the last pixel of the aforesaid first segment and is turned on for the first pixel of the next segment. In this manner, double inversions that cause fill splinters are avoided. The data processing system also employs a method for rendering vectors with pen widths of varying magnitude where, based upon the angle of inclination of the vector, its end points are derived. The end points are then modified by addition of integer offset values to take into account differences between given pen widths and pixel-integer pen widths. Then, resultant co-ordinate end points are revised to provide an approximately square end, based upon the found angle of inclination. A procedure is also described for assuring a best choice of a pixel to turn ON at an intersection of line segments.

Growing community of inventors

Meridian, ID, United States of America

Jeff H Papke