Methods and systems are disclosed for processing image frames to reduce the bandwidth requirements. Embodiment of the present invention may include mode-specific image frame rendering in photorealistic and non-photorealistic modes, such as outline and cartoon modes. In embodiments, update regions may be identified and reduced by an edge position mask. In embodiments, update regions may be bounded by rectangles and such regions may be reduced in number by merging regions together using various no-cost or cost approaches. To improve compressibility, regions to be transmitted that do not require updating at the receiver may be encoded as transparent.