Systems and methods for compositing an image directly from multiple source
image data for reducing system memory footprint and bandwidth and for improving
color quality of the image. The image is divided into spans, lines, and slices.
Each line includes at least one span and each slice includes at least one line.
All lines in a slice have spans associated with identical sources. An image is
composited by reading the image data directly from one or more sources of each
span. If necessary, the sources are blended. A control structure is used to provide
the image context and identifies the sources of the spans. The control structure
includes headers for each data stream from each source of each span. Also, the
color quality of the image is improved by reducing the number of color space conversions
that occur as the image is composited. All sources in the same color space are
blended before being blended with sources from other color spaces. Preferably,
no more than a single color conversion is required.
