Error diffusion with color conversion and encoding
AssigneeApple Inc.
InventorsYeping Su, Jiefu Zhai, James Oliver Normile, Hsi-Jung Wu, Hao Pan
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Abstract
YCbCr image data may be dithered and converted into RGB data shown on a 8-bit or other bit display. Dither methods and image processors are provided which generate the banding artifact free image data during this process. Some methods and image processors may applying a stronger dither having a same mean with a larger variance to the image data before it is converted to RGB data. Others methods and image processors may calculate a quantization or encoding error and diffuse the calculated error among one or more neighboring pixel blocks.
Claims21
A dithering method comprising:
- encoding an original pixel block and generating a reconstructed pixel block therefrom;
- comparing values of the original pixel block and the reconstructed pixel block;
- applying an error function to a difference between the compared values to calculate an error statistic using a processing device;
- and
- incorporating the error statistic in at least one value of at least one neighboring pixel block to the original pixel block.
A dithering method comprising:
- encoding an original pixel block and generating a reconstructed pixel block therefrom;
- comparing values of the original pixel block and the reconstructed pixel block;
- applying an error function to a difference between the compared values to calculate an error statistic using a processing device;
- and
- incorporating the error statistic for a selected pixel in the original pixel block in at least one neighboring pixel value to the selected pixel in the original pixel block.
Dependencies are inferred from the claim text.