Patent ID: 7460276
Filing Date: 2008-12-02
Classification: H04N

Abstract:
1. A method of halftoning an image, the method comprising: quantizing a selected target pixel of a received image; determining a quantization error for the selected target pixel; selecting a diffusion mask encompassing pixels that have not yet been processed, the mask relating to the target pixel and pixels neighboring thereto; receiving a first pair of neighboring pixel values for a first pixel pair including a first neighboring pixel and a second neighboring pixel; receiving a second pair of neighboring pixel values for a second pixel pair including a third neighboring pixel and a fourth neighboring pixel; determining a ranking order of the first, second, third and fourth neighboring pixels by comparing the first neighboring pixel value with the second neighboring pixel value and comparing the third neighboring pixel and the fourth neighboring pixel, where the first neighboring pixel and the second neighboring pixel are closer to the target pixel than the third neighboring pixel and the fourth neighboring pixel; and diffusing error to at least one of the first, second, third and fourth neighboring pixels based on the determined ranking order of the first, second, third and fourth neighboring pixels.