Canon Kabushiki Kaisha

David Christopher Smith

Giles Anderson Puckett

Thomas Benjamin Sanjay Thomas

Disclosed is a system () for printing a page description comprising a set of instructions, conforming to an interface, to draw at least one object on a page. The system comprises a filter module () for simplifying the set of instructions to an output set of instructions that is a subset of the interface, and an output device () for printing said output set of instructions. The system also has a set of thresholds () and flags () controlling the method by which the filter module simplifies said set of instructions, the flags and thresholds being dependent on the capabilities of the output device.

Threshold-based load balancing printing system

Disclosed is a method of band rendering an image. The method comprises receiving () object data of the image in the page description language. From this the method determines a plurality of buckets (bucket #-#, FIG.) by which the object data is to be divided. The method then assigns (FIG.) object data of each object in the image to one of the buckets based on an initial visibility of the object in the image. Then, for each band of the image, in a band sequential fashion (), the method identifies (-) object data visible within a band from a subset of the buckets active for the band. Then, the method analysis (FIGS.()-();-) the identified object data within the band and selects at least one rendering method (RCCR, PCR) from a plurality of rendering methods by which the band is to be rendered. Then the method renders () the identified object data into the band from the object data using the selected at least one rendering method.

Efficient banded hybrid rendering

A method of rendering an image described by a list of graphical objects includes the steps of assigning objects in the list to at least one of a first set of objects and a second set of objects, and rendering the first set of objects to an image store using a first rendering method that determines whether a portion of an object of the first set contributes to a rendered output of the first set of objects and, if so, the first rendering method renders each pixel of the portion in sequence. The second set of objects to the image store are rendered using a second rendering method that renders each object in the second set in sequence and independently of the other objects in the second set.

Method of rendering graphic objects

A method and apparatus for generating a display list, for use in rendering a plurality of glyphs, is disclosed. The method creates a display list for storing representations of the glyphs and stores at least a first one of the glyphs in the display list as a bitmap representation depending on one or more predetermined criteria. The at least first one of the glyphs may alternatively be stored in the display list as a vector representation.

Method for generating a display list

An apparatus renders a plurality of graphical objects of an image on a scanline basis, with each scanline including at least one run of pixels, and each run of pixels being associated with at least one of the graphical objects such that the pixels of the run are within the edges of the at least one graphical object. The apparatus includes a decomposer for decomposing each of the graphical objects into at least one edge representing the corresponding graphical objects, a sorter for sorting one or more arrays containing the edges representing the graphical objects of the image, at least one of the arrays being sorted in an order from a highest priority graphical object to a lowest priority graphical object, and a determining device for, using the one or more arrays, determining edges of the graphical objects defining a run of pixels of at least one of the scanlines, graphical objects contributing to the run of pixels and edges of the contributing graphical objects. In addition, a generator generates the run of pixels by halftoning fill data within the edges of a highest priority contributing graphical object, if the highest priority graphical object contributing to the run of pixels is opaque, and the determining device determines a tiled representation of a portion of the highest priority contributing graphical object using the halftone fill data, wherein the tiled representation is used to generate subsequent runs of pixels corresponding to the highest priority contributing graphical object. Otherwise, the generator generates the run of pixels by compositing data associated with the highest priority contributing graphical object and one or more of further contributing graphical objects and halftoning the composited data.

System and method for optimising halftoning printer performance

A method of rendering a plurality of graphical objects of an image on a scanline basis, with each scanline having at least one run of pixels, and each run of pixels being associated with at least one of the graphical objects such that the pixels of the run are within edges of the at least one graphical object, includes the steps of decomposing each of the graphical objects into at least one edge representing the corresponding graphical object, and sorting one or more arrays containing the edges representing the graphical objects of the image. At least one of the arrays is sorted in an order from a highest priority graphical object to a lowest priority graphical object. Additional steps include, for each run of pixels of each scanline, determining edges of the graphical objects defining the run, graphical objects contributing to the run of pixels and edges of the contributing graphical objects, using the one or more arrays, and generating the run of pixels by halftoning pixel data within the edges of a highest priority contributing graphical object, if the highest priority contributing graphical object is opaque, otherwise, compositing data associated with the highest priority contributing graphical object and one or more further contributing graphical objects, and halftoning the composited data.

A method () and apparatus () for determining active objects contributing to a run of pixels corresponding to a scanline is disclosed. The methodutilizes two memory () integer arrays () and () of size N, where N represents the number of objects in a job to be rendered. The first array () is an active priority list and is preferably stored in memory (). The first array () will be hereinafter referenced as the 'active priority list (i.e. L[ ])'. The second array () is an array of pointers (i.e. indexes) that indicate vacant memorylocations in the active priority list (), when an object is deactivated. The second array () will be hereinafter referred to as a 'free list (F[ ])' and is also preferably stored in memory (). The active priority list () and free list () can be stored at consecutive memory () addresses (e.g. Memory address 0 to memory address 2N) or alternatively, the active priority list () and free list () can be stored in any suitable free memory () locations.

Growing community of inventors

Bridgewater, Australia

David Christopher Smith