Method and apparatus for windowing and image rendition

A method for processing and rendering image data during a single pass through an image, comprising the following steps:

• a) loading scanlines of image data into a first-in-first-out rolling band buffer until the buffer is full;
• b) performing windowing on the image data in the buffer to generate windows and classify windows according to an image type class;
• c) processing image data for each window in the output scanline of the buffer using a class-based rendering algorithm associated with the image type class for the window;
• d) rendering the processed image data for the output scanline of the buffer to a rendering device;
• e) loading the next scanline of image data into the buffer;
• f) performing windowing on the image data in the buffer to generate windows and classify windows according to an image type class;
• g) determining if a class change was experienced by any window in the output scanline of the buffer during traverse of the scanline from the input of the buffer to the output of the buffer;
• h) if a class change was experienced for a window in the output scanline of the buffer, processing image data in the output scanline for that window using a blended rendering algorithm;
• i) if a class change was not experienced for a window in the output scanline of the buffer, processing image data in the output scanline for that window using a class-based rendering algorithm associated with the image type class for the window;
• and
• j) rendering the processed image data for the output scanline of the buffer to a rendering device.

An image processor for processing image data during a single pass through an image, comprising:

• a first-in-first-out rolling band buffer for receiving image data in a scanline by scanline fashion from a source, the buffer comprising a plurality of scanlines, including an input scanline and an output scanline;
• a windowing processor in communication with the buffer for segmenting the image data in the buffer into windows and classifying each window according to an image type class, and determining if blended rendering is required for a window;
• class-based rendering algorithms in communication with the buffer and the windowing processor and associated with image type classes for processing image data associated with a portion of one or more windows in the output scanline according to the image type class associated with the window;
• and
• a blended rendering algorithm in communication with the class-based rendering algorithms and the windowing processor for blending processed image data from the class-based rendering algorithms for each window portion in the output scanline requiring blended rendering.