US 6,476,934 B1 · Geometrically reducing influence halftoning

Abstract

Methods and apparatus for processing an image is disclosed. First an output value of a first current pixel (inx,y−1), which is not at an edge of the image, is determined using a first influence value (Wx,y−2) for a first current pixel which equals a first sum, over a first set of pixels, of the product of a pixel weight value and a corresponding pixel value, where the pixel weight value is substantially equal to a weight factor (X, Z) raised to the power (i) of the distance of the pixel from the first current pixel. An output value for a second current pixel (inx,y), is determined using a second influence value (Wx,y−1) determined as either a product of a weight value reducing factor (X) and the first influence value, or a product of weight value reducing factor and the sum of the first influence value and a value for the first current pixel, where the second influence value equals a second sum over a second set of pixels of the product of a pixel weight value and a corresponding pixel value, and where each pixel weight value is substantially equal to a weight factor raised to the power of the distance of the pixel from the second current pixel.

Claims79

Dependent claims

A method of processing an image, said image comprising a plurality of pixels, said method comprising the steps of:

(a) determining an output value of a first current pixel, which is not at an edge of the image, using a first influence value for a first current pixel which equals a first sum, over a first set of pixels, of the product of a pixel weight value and a corresponding pixel value, where the pixel weight value is substantially equal to a weight factor raised to the power of the distance of the pixel from the first current pixel;
and
(b) determining an output value for a second current pixel, using a second influence value determined as either:
(i) a product of a weight value reducing factor and the first influence value, or
(ii) a product of a weight value reducing factor and the sum of the first influence value and a value for the first current pixel,
so that the second influence value equals a second sum over a second set of pixels of the product of a pixel weight value and a corresponding pixel value, where each pixel weight value is substantially equal to a weight factor raised to the power of the distance of the pixel from the second current pixel.

3 more elements

A method of halftoning an image, said image comprising a plurality of pixels each having an input value and in assignable output value that can take on one of at least two output values, said method comprising the steps of:

(a) determining an output value of a first current pixel, which is not at an edge of the image, using a first influence value for a first current pixel which equals a first sum, over a first set of pixels, of the product of a pixel weight value and a corresponding pixel error value, where the pixel weight value is substantially equal to a weight factor raised to the power of the distance of the pixel from the first current pixel;
and
(b) for the purpose of determining an output value for a second current pixel, calculating a second influence value for the second current pixel
(i) as a product of a weight value reducing factor and the first influence value, or
(ii) as a product of a weight value reducing factor and the sum of the first influence value and an error value for the first current pixel,
so that the second influence value equals a second sum over a second set of pixels of the product of a pixel weight value and a corresponding pixel error value, where the pixel weight value is substantially equal to a weight factor raised to the power of the distance of the pixel of the second set from the second current pixel.

3 more elements

A method of halftoning an image, said image comprising a plurality of pixels each having an input value and an assignable output value that can take on one of at least two output values, said method comprising the steps of:

(a) determining an output value of a first current pixel, which is not at an edge of the image, using a set of two or more first influence values for a first current pixel where each first influence value equals a sum, over a first set of pixels, of the product of a pixel weight value and a corresponding pixel error value, where the pixel weight value is substantially equal to a weight factor raised to the power of the distance of the pixel from the first current pixel;
and
(b) for the purpose of determining an output value for a second current pixel, calculating a set of two or more second influence values for the second current pixel where each second influence value is calculated
(i) as a product of a weight value reducing factor and one of the first influence values, or
(ii) as a product of a weight value reducing factor and the sum of one of the influences value and an error value for the first current pixel,
so that each second influence value equals a sum over a second set of pixels of the product of a pixel weight value and a corresponding pixel error value, where the pixel weight value is substantially equal to a weight factor raised to the power of the distance of the pixel of the second set from the second current pixel.

3 more elements

An apparatus for processing an image, said image comprising a plurality of pixels each having an input value, said apparatus comprising:

(a) means for determining an output value of a first current pixel, which is not at an edge of the image, using a first influence value for a first current pixel determined from a first function, over a first set of pixels, of pixel weight values, where each pixel weight value is substantially equal to a weight factor raised to the power of the distance of the pixel from the first current pixel;
and
(b) means for determining an output value for a second current pixel using a second influence value for the second current pixel determined from a second function of a weight value reducing factor and the first influence value,
so that the second influence value is related to a third function including a pixel weight value, where the pixel weight value is substantially equal to a weight factor raised to the power of the distance of the pixel of the second set from the second current pixel.

1 more element

Apparatus for halftoning an image, said image comprising a plurality of pixels each having an input value and an assignable output value that can take on one of at least two output values, said apparatus comprising:

(a) means for determining an output value of a first current pixel, which is not at an edge of the image, using a first influence value for a first current pixel which equals a first sum, over a first set of pixels, of the product of a pixel weight value and a corresponding pixel error value, where the pixel weight value is substantially equal to a weight factor raised to the power of the distance of the pixel from the first current pixel;
and
(b) means for determining an output value for a second current pixel, by calculating a second influence value for the second current pixel
(i) as a product of a weight value reducing factor and the first influence value, or
(ii) as a product of a weight value reducing factor and the sum of the first influence value and an error value for the first current pixel,
so that the second influence value equals a second sum over a second set of pixels of the product of a pixel weight value and a corresponding pixel error value, where the pixel weight value is substantially equal to a weight factor raised to the power of the distance of the pixel of the second set from the second current pixel.

3 more elements

(a) means for determining an output value of a first current pixel, which is not at an edge of the image, using a set of two or more first influence values for a first current pixel where each first influence value equals a sum, over a first set of pixels, of the product of a pixel weight value and a corresponding pixel error value, where the pixel weight value is substantially equal to a weight factor raised to the power of the distance of the pixel from the first current pixel;
and
(b) means for determining an output value for a second current pixel, by calculating a set of two or more second influence values for the second current pixel where each second influence value is calculated
(i) as a product of a weight value reducing factor and one of the first influence values, or
(ii) as a product of a weight value reducing factor and the sum of one of the influences value and an error value for the first current pixel,
so that each second influence value equals a sum over a second set of pixels of the product of a pixel weight value and a corresponding pixel error value, where the pixel weight value is substantially equal to a weight factor raised to the power of the distance of the pixel of the second set from the second current pixel.

3 more elements

Dependencies are inferred from the claim text.

Geometrically reducing influence halftoning

Life of this patent

Geometrically reducing influence halftoning

Life of this patent

Abstract

Claims79