Method for rendering an image comprising multi-level pixels

A method of rendering a halftone cell of an image by halftoning comprising an array of dots, a dot comprising a least one pixel, said method comprising the steps of:

• (a) rendering a visually perceptible first dot at a first intensity based on a first transfer function for a first location;
• (b) rendering a visually perceptible second dot at substantially said first intensity based on said first transfer function for a second location, said second dot being displaced vertically and horizontally in said array from said first dot;
• (c) rendering a visually perceptible third dot at a second intensity based on a second transfer function for third location, said second intensity being greater than a minimum intensity, less than a maximum intensity, and substantially different from said first intensity;
• and
• (d) rendering a visually perceptible fourth dot at substantially said second intensity based on said second transfer function for a forth location, said fourth dot being displaced vertically and horizontally relative to said third dot.

A method of rendering an image by halftoning comprising a plurality of halftone cells, said method comprising the steps of:

• (a) sampling an intensity of an original image at a plurality of locations;
• (b) rendering a visually perceptible first pixel of a halftone cell at a first intensity in response to a first sample, said first intensity relating a first location and an intensity of said first sample based on a first transfer function for said first location;
• and
• (c) rendering a visually perceptible second pixel of said halftone cell at a second intensity in response to a second sample, said second intensity relating a second location and an intensity of said second sample based on said second transfer function for said second location and being greater than a minimum intensity, less than a maximum intensity, and substantially different from said first intensity.