Patent ID: 6594030
Filing Date: 2003-07-15
Classification: G06F

Abstract:
In a desktop publishing application program for operating on a publication comprising a first page object and a second page object, the first page object having a higher Z-order than the second page object, a method for trapping the first page object against the second page object comprising the steps of:decomposing the first page object into one or more first page object components; creating a first trap source list comprising one or more first trap candidate segments from the first page object components, the trap candidate segments comprising exposed edges of the first page object components that intersect or abut the second page object; for each of the first trap candidate segments in the first trap source list: detecting whether a potential adjacency trapping situation exists between the first trap candidate segment and the second page object, in response to detecting the potential adjacency trapping situation, performing adjacency trapping between the first trap candidate segment and the second page object to create a trap segment and to remove from the first trap source list any portion of the first trap candidate segment that maps to the trap segment, and performing a color test to determine whether the trap segment is to be added to a trap output list or deleted; for each of the first trap candidate segments in the first trap source list: detecting whether a potential general-purpose trapping situation exists between the first trap candidate segment and the second page object, in response to detecting the potential general-purpose trapping situation, performing general-purpose trapping between the first trap candidate segment and the second page object to create a next trap segment and to remove from the first trap source list any portion of the first trap candidate segment that overlays the second page object, and in response to creating the next trap segment, performing a color test to determine whether the next trap segment is to be added to the trap output list or deleted; and rendering the trap segments from the trap output list onto appropriate color plates to hide misregistration errors between the first page object and the second page object.