Abstract: Methods and apparatus, including computer program apparatus, implementing techniques for preparing a region of an electronic document for printing on a printing device having asymmetric misregistration behavior. The techniques include trapping the region asymmetrically to compensate for asymmetric misregistration behavior of a printing device. The region can be an entire page or a portion of a page represented in a page description language or a raster representation. The techniques can include defining an asymmetric transformation; applying the asymmetric transformation to the region to generate a transformed region; processing the transformed region to generate transformed traps; and applying an inverse transformation to the transformed traps to generate traps for the region, the inverse transformation being an inverse of the asymmetric transformation.

Abstract: A virtual view tree for representing a document. A virtual view tree is maintained by an application, rather than a renderer (e.g., graphics rendering library) called upon by the application to display the document. The view tree is virtual in that nodes need not be created until they are to be displayed. When instructed to display the document, the renderer requests nodes and their attributes. The nodes may be cached while the renderer works on their content, but may be removed from memory anytime thereafter. Only a subset of the virtual view tree's nodes is stored at one time, and only in non-persistent storage. The application includes various APIs for navigating a virtual view tree, describing its attributes and caching its nodes. The APIs may be directly accessible to the renderer or may be invoked by subsystems of the application (e.g., client, tree navigation and caching subsystems).

Abstract: A virtual view tree for representing a document. A virtual view tree is maintained by an application, rather than a renderer (e.g., graphics rendering library) called upon by the application to display the document. The view tree is virtual in that nodes need not be created until they are to be displayed. When instructed to display the document, the renderer requests nodes and their attributes. The nodes may be cached while the renderer works on their content, but may be removed from memory anytime thereafter. Only a subset of the virtual view tree's nodes is stored at one time, and only in non-persistent storage. The application includes various APIs for navigating a virtual view tree, describing its attributes and caching its nodes. The APIs may be directly accessible to the renderer or may be invoked by subsystems of the application (e.g., client, tree navigation and caching subsystems).

Abstract: Methods and apparatus, including computer program apparatus, implementing techniques for preparing a region of an electronic document for printing on a printing device having asymmetric misregistration behavior. The techniques include trapping the region asymmetrically to compensate for asymmetric misregistration behavior of a printing device. The region can be an entire page or a portion of a page represented in a page description language or a raster representation. The techniques can include defining an asymmetric transformation; applying the asymmetric transformation to the region to generate a transformed region; processing the transformed region to generate transformed traps; and applying an inverse transformation to the transformed traps to generate traps for the region, the inverse transformation being an inverse of the asymmetric transformation.

Abstract: Methods and-apparatus implementing a technique for forming a trap polygon which does not interfere with the print quality of other trap polygons or objects. Edges in close proximity to a color transition edge (“CTE”) are checked for potential interference. A trap polygon is formed for the CTE that avoids any interfering edges or trap polygons for those edges. The technique can be applied to form a trap polygon for each edge in a page to be printed.

Abstract: An assembly for processing a service used by a component-based application is provided by receiving a request from the component-based application that specifies a role name symbolizing the task, accessing an assembly data-structure corresponding to the role name and having metadata information specifying a number of components used to perform the service and interfaces used to connect each component with other components, loading a component identified in the assembly data-structure into an area for processing, connecting an interface associated with the loaded component to other components according to the meta-data information in the assembly data-structure, and performing the requested service using the loaded component to process data and the interface to pass information from the loaded component to other components.

Abstract: Methods and apparatus, including computer program products, implementing and using techniques for processing a computer graphics illustration, the computer graphics illustration having overlapping objects. At least a region of the computer graphics illustration is broken up into tiles, without regard to the overlapping objects. The objects in each tile are processed to create vector output representing the tiled region of the computer graphics illustration. In one implementation, the boundaries of the tiles overlap. In an alternative implementation, the tiles are adjacent. In the latter implementation, information is obtained about physical pixel boundaries in an output device space, and each tile includes only pixels of the output device space that are wholly within the tile.

Abstract: Methods and-apparatus implementing a technique for forming a trap polygon which does not interfere with the print quality of other trap polygons or objects. Edges in close proximity to a color transition edge (“CTE”) are checked for potential interference. A trap polygon is formed for the CTE that avoids any interfering edges or trap polygons for those edges. The technique can be applied to form a trap polygon for each edge in a page to be printed.

Abstract: Methods and apparatus implementing a technique for forming a trap polygon which does not interfere with the print quality of other trap polygons or objects. Edges in close proximity to a color transition edge (“CTE”) are checked for potential interference. A trap polygon is formed for the CTE that avoids any interfering edges or trap polygons for those edges. The technique can be applied to form a trap polygon for each edge in a page to be printed.

Abstract: A method of trapping objects for a page includes identifying sequential matching objects, combining into a larger object matching sequential objects including parameterizing each object as a band in the larger object and trapping non-matching objects and the larger object. In another aspect, a method of preparing a page to be printed is provided that includes receiving a page description language file describing the page to be printed, identifying sequential matching objects in the page description file that represent a gradient to be printed on the page and combining into a larger object matching sequential objects. The step of combining includes defining an outline for the object and a defining a function describing the coloring for the object.

Abstract: Methods and apparatus, including computer program products, implementing and using techniques for processing a computer graphics illustration, the computer graphics illustration having overlapping objects. At least a region of the computer graphics illustration is broken up into tiles having overlapping boundaries, without regard to the overlapping objects. The objects in each tile are planarized to create flattened vector output representing the tiled region of the computer graphics illustration.

Abstract: Methods and apparatus implementing a technique for forming a trap polygon which does not interfere with the print quality of other trap polygons or objects. Edges in close proximity to a color transition edge (“CTE”) are checked for potential interference. A trap polygon is formed for the CTE that avoids any interfering edges or trap polygons for those edges. The technique can be applied to form a trap polygon for each edge in a page to be printed.

Abstract: Method and apparatus for rasterizing a resolution-independent page description for printing. A peeker (gap between two visible edges in vector representation that is narrower than a printer pixel) is identified between a first visible edge and a second visible edge, and a color adjustment is made to at least one of the edges. In one embodiment, a side of the second visible edge facing a side of the first visible edge is identified. The color of the identified side of the first visible edge is changed based on the color of the identified side of the second visible edge. The color adjustment is advantageous in connection with methods of trapping.

Abstract: A method for automatic compensation for misregistration of printing plates in printing of polychromatic document pages or images, in which a trapping map image is superimposed upon the structured graphic image representing the layout of the document page or image from which it is derived, so as to prevent light leaks and other errors at the boundaries between color regions within the image. Traps are selected automatically and applied to a boundary map comprising the set of boundaries between regions of different color of the original image. The selection process uses the results of a plurality of separate methods for ranking possible traps each of which is assigned an overall score by means of a weighted sum of the ranks obtained by each of the separate methods, with the resulting score used as the basis for automatic trap selection among the set of possible traps.

Abstract: A method and apparatus for compensation for misregistration of printing plates in printing of polychromatic document pages or images, in which a trapping map image is superiraposed upon a structured graphic image representing the layout of a document page or image from which it is derived, so as to prevent light leaks and other errors at the boundaries between color regions within the image. The trapping map image is itself a structured graphic object to be included as the last object imaged in the data representing the original image. The geometrical description of this trapping map image is independent of specific trapping decisions applicable to the associated image. Instead, such decisions are controlled by means of a user interface providing options ranging from fully automatic to completely manual interactive operation.

Abstract: A method for determining the boundaries between regions of color making up polychromatic document pages or images, in order to compensate for misregistration of printing plates in printing, and thereby to prevent light leaks and other errors at the boundaries so determined. A map of the boundaries is generated, to which trapping operations are applied to form a structured graphic object that is included as the last object imaged in the data representing the original image. The geometrical description of the boundary map determined according to the method of the invention is independent of specific trapping decisions applicable to the associated image.