Strategies for producing quantized image information
First Claim
1. A computer-implemented method for quantizing and dithering original image information to produce quantized image information, comprising:
- quantizing for a first pixel in an image a sum that combines an original value taken from the original image information, a noise value, and an error term, to produce a high-precision quantized value;
rounding the high-precision quantized value to a nearest low-precision number;
storing the nearest low-precision number in a pixel array;
calculating an error term by computing a difference between the stored nearest low-precision number and the original value; and
utilizing the calculated error term from the first pixel to quantize a sum for a second pixel.
1 Assignment
0 Petitions
Accused Products
Abstract
Strategies are set forth herein for quantizing and dithering original image information to produce quantized image information. According to one exemplary implementation, the strategies involve: quantizing a sum that combines an original value taken from the original image information, a noise value, and an error term, to produce a quantized value; and calculating an error term for a subsequent quantizing operation by computing a difference between the quantized value and the original value. By virtue of his process, the strategies essentially add noise information to the quantization process, not the original image information, which results in quantized image information having reduced artifacts. The strategies can be used in conjunction with the Floyd-Steinberg error dispersion algorithm. According to another feature, the noise value is computed using a random number generator having a long repeat period, which further reduces artifacts.
-
Citations
20 Claims
-
1. A computer-implemented method for quantizing and dithering original image information to produce quantized image information, comprising:
-
quantizing for a first pixel in an image a sum that combines an original value taken from the original image information, a noise value, and an error term, to produce a high-precision quantized value; rounding the high-precision quantized value to a nearest low-precision number; storing the nearest low-precision number in a pixel array; calculating an error term by computing a difference between the stored nearest low-precision number and the original value; and utilizing the calculated error term from the first pixel to quantize a sum for a second pixel. - View Dependent Claims (2, 3, 4, 5, 6, 7, 16, 17)
-
-
8. An apparatus for quantizing and dithering original image information to produce quantized image information, comprising:
-
a noise generator configured to produce noise values; and a dithering module configured to produce the quantized image information iteratively by; quantizing for a first pixel in an image a sum that combines an original value taken from the original image information, a noise value from the noise generator, and an error term, to produce a high-precision quantized value; rounding the high-precision quantized value to a nearest low-precision number; storing the nearest low-precision number in a pixel array; calculating an error term by computing a difference between the stored nearest low-precision number and the original value; and utilizing the calculated error term from the first pixel to quantize a sum for a second pixel. - View Dependent Claims (9, 10, 11, 12, 13, 14)
-
-
15. An apparatus for quantizing and dithering original image information to produce quantized image information, comprising:
-
means for quantizing for a first pixel in an image a sum that combines an original value taken from the original image information, a noise value, and an error term, to produce a high-precision quantized value; means for rounding the high-precision quantized value to a nearest low-precision number; means for storing the nearest low-precision number in a pixel array; means for calculating an error term by computing a difference between the stored nearest low-precision number and the original value; and means for utilizing the calculated error term from the first pixel to quantize a sum for a second pixel. - View Dependent Claims (18, 19, 20)
-
Specification