The present invention overcomes the limitations of the prior art by providing a system and method for halftoning using time-variable halftone patterns. Successive frames that are presented to the output device are individually halftoned. The halftone pattern is changed from frame to frame. The different halftone patterns can be generated in real time, or they can be calculated prior to halftoning and stored in memory. Additionally, the halftone patterns can be generated using any conventional halftoning technique. The same halftoning technique can used to create each halftone pattern, or the halftoning techniques can be varied when creating halftone patterns. The halftoned frames are then viewed in a sequence in time. Because the halftone pattern is changing from frame to frame, the visibility of the pattern is reduced when compared with the patterns produced by prior art halftoning methods.
A display system provides temporal stochastic dithering to image data for storage in a frame buffer for display. Stochastic dithering is used to reduce the size of the frame buffer and the complexity of the drive circuitry that is used to display an image in accordance with the image data. The bit depth of the frame buffer is reduced by spatially dithering image data for the image data before the image data is written into the frame buffer. Additionally, the displayed image is temporally dithered by using a different dither pattern for successive frames. Uncorrelated stochastic dither patterns are used to minimize detection of the dither patterns within the displayed image.
