Fitzpatrick, Cella, Harper & Scinto
Tree-based compositing system
A method of rendering a graphical image described by an expression tree is disclosed. The expression tree has one or more parent nodes and one or more leaf nodes, with each parent node representing a graphical operator and having branches to respective descendent nodes. Each of the leaf nodes represents a graphic object. The method determines regions of one or more pixel locations in an output space of the image, with each region corresponding to a combination in the image of one or more of the graphical objects. Next, for each of the regions, an activity state of corresponding parent nodes is determined using a predefined function for each corresponding operator. The method then generates, in parallel, for each active one of the operators, compositing instructions and pixel generation instructions. The compositing instructions are stored in an operator queue and pixel colors are generated using the pixel generation instructions, with the pixel colors being buffered in an operand queue. Lastly, the generated pixel colors are composited, for each pixel in the region, using the operators defined in the operator queue, to output a composited pixel value for each pixel in the region.
Canon Kabushiki Kaisha
G Y
G06T Y10S
inventional additional
Yu-Ling
Chen