Canon Kabushiki Kaisha

Kevin John Moore

Timothy Merrick Long

Christopher Fraser

James Philip Andrew

Alexander Vincent Danilo

Kok Tjoan Lie

James David Clark

Peter Leslie Bell

Richard James Zillman

Craig William Northway

A method of rendering a graphical object on a page in a pixel sequential renderer () processing a page having a plurality of scanlines, is disclosed. Each of the scanlines is divided into at least a first swathe and a second swathe. The method tracks a plurality of edges of the graphical object and sorts a first portion of the tracked edges on a first swathe of one or the plurality of scanlines using a first sorter to control first activation information. A second portion of the tracked edges on a second swathe of said one of the plurality of scanlines is sorted using a second sorter to control second activation information and the second activation information is synchronized with the first activation information. The graphical object is rendered on the page in the pixel sequential renderer () using the first and the synchronized second activation information.

Method, apparatus and system for rendering an object on a page

Disclosed is a method of rendering a radial gradient blend defined by a gradient function. The method identifies respective first and second radial limits for a point of the radial gradient blend, the respective first and second radial limits having known blend values and receives an estimated value of the gradient function for the point. The method determines a direction from the estimated value to an ideal value, wherein the ideal value is a value of the gradient function for the point and modifies the estimated value, based on the direction of the ideal value. The method checks the ideal value is within a predetermined threshold of the estimated value and stores a determined blend value for the point by interpolating between the known blend values of the respective first and second radial limits on the basis of the modified estimated value of the gradient function, to render the radial gradient blend.

Efficient radial gradient fills

In a method of compositing graphic elements in a pixel-based renderer, a first graphic element is received having a first color and a first opacity, and a second graphic element is received having a second color and a second opacity. A blend output is obtained from a blend function dependent on the first color and the second color, and a resultant color is determined of a compositing operation on the first and second graphic elements, with the resultant color being dependent on the blend output and otherwise being independent of the second color.

Implementing compositing operations on images

An apparatus for recording an object-based image one pixel at a time in scanline order includes an optimization module for generating a set of compositing messages corresponding to a first pixel and generating a reduced set of compositing messages from the set of compositing messages, and a pixel compositing module which, in addition to compositing the first pixel using the set of compositing messages, stores a result or partial result of the compositing of the first pixel. The pixel compositing module utilizes the reduced set of compositing messages and the stored result or partial result to composite at least one subsequent pixel, and the first pixel and the at least one subsequent pixel form part of a run of pixels along a scanline of the image between adjacent edges of objects in the object-based image.

Reducing the number of compositing operations performed in a pixel sequential rendering system

Disclosed are methods, apparatus () and computer readable media for rendering at least one graphic object () described by at least one edge (--) into a raster pixel image () having a plurality of scan lines and a plurality of pixel locations on each scan line. For each scan line, coordinates of intersection of those edges of the objects that intersect the scan line are determined in a predetermined order. This is preferably achieved by processing edge records () using a number of buffers () thereby enabling efficient sorting of edge intersections into order. For each adjacent pair of edge intersections, information () associated with the corresponding object is examined to determining a set of active objects () for a span of pixel locations between the corresponding pair of edge intersections. For each span of pixel locations, the corresponding set of active objects is used to determine () a value for each of the locations within the span. The information may include one or more of a fill count, a clip count and other factors. A compositing model accommodating opacity is also disclosed, as are stack operations used to facilitate rendering and other features which contribute to fast processing of image components.

Rendering graphic object based images

Processing graphic objects for fast rasterised rendering

Apparatusis disclosed for rendering an object-based image one pixel at a time in scanline order. The apparatuscomprises an optimisation modulefor generating a set of compositing messages during a first pixel in a run of pixels between adjacent edges of one or two objects, and for generating a reduced set of compositing messages from the set during subsequent pixels in the run of pixels. The apparatusfurther comprises a pixel compositing modulewhich in addition to compositing the first pixel in the run of pixels also stores a result or partial result of the compositing of the first pixel. The pixel compositing moduleutilises the reduced set of compositing messages and the stored result or partial result to composite pixels in the run subsequent to the first pixel.

Disclosed are methods, apparatus ( ) and computer readable media for rendering at least one graphic object ( ) described by at least one edge ( ) into a raster pixel image ( ) having a plurality of scan lines and a plurality of pixel locations on each scan line. For each scan line, coordinates of intersection of those edges of the objects that intersect the scan line are determined in a predetermined order. This is preferably achieved by processing edge records ( ) using a number of buffers ( ) thereby enabling efficient sorting of edge intersections into order. For each adjacent pair of edge intersections, information ( ) associated with the corresponding object is examined to determining a set of active objects ( ) for a span of pixel locations between the corresponding pair of edge intersections. For each span of pixel locations, the corresponding set of active objects is used to determine ( ) a value for each of the locations within the span. The information may include one or more of a fill count, a clip count and other factors. A compositing model accommodating opacity is also disclosed, as are stack operations used to facilitate rendering and other features which contribute to fast processing of image components.

Fast rendering techniques for rasterised graphic object based images

An apparatus includes a DCT unit for transforming blocks of pixels into respective blocks of transform coefficients, entropy encoders for encoding respective partitions of the DCT blocks where at least one partition comprises bit-plane data from each block of transform coefficients, and a scan output manager for storing the entropy encoded partitions in a buffer of fixed memory size. The manager manages the storing of the coded partitions in the buffer whereby during the storing of the coded partitions if it is determined the buffer is full, a coded least perceptually significant partition currently stored in the buffer is overwritten by data from a coded more perceptually significant partition.

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North Ryde, Australia

Kevin John Moore