Patent ID: 7206001

Claim:
A method for dithering an image having a plurality of 16-bit color channel pixel planes, each pixel plane having a plurality of pixels, each pixel having a 16-bit value, the method comprising: for each pixel, dividing the pixel value into a first portion including the 8 most-significant bits of the pixel value and a second portion including the 8 least-significant bits of the pixel value channel; dividing the bits of the second portion into a third portion, including the 4 most-significant bits of the second portion, and a fourth portion, including the 4 least-significant bits of the second portion; comparing the bits of the third portion to a first entry in a 4-by-4 matrix A, accessed by A x%4,y%4 ; where x and y represent coordinates of the pixel within the pixel plane; responsive to the bits of the third portion being greater than the first entry in the matrix, incrementing the value of the first portion of the pixel value; responsive to the bits of the third portion equaling the first entry in the matrix: comparing the bits of the fourth portion to a second entry in the matrix A, accessed by a different scaling of the pixel plane; and responsive to the bits of the fourth portion being greater than the second entry, incrementing the value of the first portion of the pixel value.