US 8,428,386 B2 · Using separate coefficients to weight and add separate images together from a spatial filter process

Abstract

A local density calculation section calculates a density of a pixel region with a predetermined size including a current point of an input image disposed at the center on the basis of a pixel value of the pixel region. A mixing ratio calculation section generates a coefficient set of coefficients α and β in accordance with a local density value calculated by the local density calculation section, and outputs the generated coefficients α and β to a weight process section. The weight process section multiplies an operation result obtained from the input image by a first filter operation section by the coefficient α, multiplies an operation result obtained from the input image by a second filter operation section by the coefficient β, adds the multiplied results to each other and outputs the result of addition as a process result of a spatial filter process section.

Claims15

Dependent claims

An image processing apparatus performing an image process on input image data, comprising:

a density calculation section which calculates a density of a pixel region including a plurality of pixels of an input image on the basis of a pixel value of the pixel region;
a first process section which performs a smoothing process on the input image data;
a second process section which performs a process having both an enhancement characteristic and a smooth characteristic on the input image data;
a weighting coefficient setting section which sets, in accordance with the density calculated by the density calculation section, a first coefficient used for weighting an image data having been processed by the first process section and a second coefficient used for weighting an image data having been processed by the second process section;
a weight process section which weights the image data having been processed by the first process section by using the first coefficient set by the weighting coefficient setting section, weights the image data having been processed by the second process section by using the second coefficient set by the weighting coefficient setting section, adds weighted image data to each other and outputs image data resulting from addition;
and
an area image discrimination section which determines, on the basis of a pixel value within a pixel block containing a plurality of pixels including a current pixel, whether or not the input image belongs to a text edge area,
wherein the weighting coefficient setting section sets the first coefficient and the second coefficient for performing the smoothing process on the input image data when the area image discrimination section determines that the input image does not belong to a text edge area and the density calculated by the density calculation section is larger than a predetermined density threshold value.

5 more elements

An image processing apparatus performing an image process on input image data, comprising:

a density calculation section which calculates a density of a pixel region including a plurality of pixels of an input image on the basis of a pixel value of the pixel region;
a first process section which performs a smoothing process on the input image data;
a second process section which performs a process having both an enhancement characteristic and a smooth characteristic on the input image data;
a weighting coefficient setting section which sets, in accordance with the density calculated by the density calculation section, a first coefficient used for weighting an image data having been processed by the first process section and a second coefficient used for weighting an image data having been processed by the second process section;
a weight process section which weights the image data having been processed by the first process section by using the first coefficient set by the weighting coefficient setting section, weights the image data having been processed by the second process section by using the second coefficient set by the weighting coefficient setting section, adds weighted image data to each other and outputs image data resulting from addition;
and
an area image discrimination section which determines, on the basis of a pixel value within a pixel block containing a plurality of pixels including a current pixel, whether or not the input image belongs to a text edge area,
wherein the weighting coefficient setting section sets the first coefficient and the second coefficient for performing the process of the second process section on the input image data when the area image discrimination section determines that the input image belongs to a text edge area.

5 more elements

An image processing apparatus performing a digital filter operation process on input image data, comprising:

a first storage section which stores a first filter coefficient used for performing a smoothing process on the input image data;
a second storage section which stores a second filter coefficient used for performing a process different from the smoothing process on the input image data;
a density calculation section which calculates a density of a pixel region including a plurality of pixels of an input image on the basis of a pixel value of the pixel region;
a weighting coefficient setting section which sets, in accordance with the density calculated by the density calculation section, a first coefficient used for weighting the first filter coefficient and a second coefficient used for weighting the second filter coefficient;
an operation section which performs a filter operation on the input image data by using at least the first filter coefficient or the second filter coefficient;
and
a weight process section which weights the first filter coefficient by using the first coefficient set by the weighting coefficient setting section, weights the second filter coefficient by using the second coefficient set by the weighting coefficient setting section, obtains a new filter coefficient by adding weighted filter coefficients to each other and outputs the new filter coefficient to the operation section;
and
an area image discrimination section which determines, on the basis of a pixel value within a pixel block containing a plurality of pixels including a current pixel, whether or not the input image belongs to a text edge area,
wherein the weighting coefficient setting section sets the first coefficient and the second coefficient for performing the filter operation on the input image by the operation section by using the first filter coefficient when the area image discrimination section determines that the input image does not belong to a text edge area and the density calculated by the density calculation section is larger than a predetermined density threshold value.

7 more elements

An image processing apparatus performing a digital filter operation process on input image data, comprising:

a first storage section which stores a first filter coefficient used for performing a smoothing process on the input image data;
a second storage section which stores a second filter coefficient used for performing a process different from the smoothing process on the input image data;
a density calculation section which calculates a density of a pixel region including a plurality of pixels of an input image on the basis of a pixel value of the pixel region;
a weighting coefficient setting section which sets, in accordance with the density calculated by the density calculation section, a first coefficient used for weighting the first filter coefficient and a second coefficient used for weighting the second filter coefficient;
an operation section which performs a filter operation on the input image data by using at least the first filter coefficient or the second filter coefficient;
and
a weight process section which weights the first filter coefficient by using the first coefficient set by the weighting coefficient setting section, weights the second filter coefficient by using the second coefficient set by the weighting coefficient setting section, obtains a new filter coefficient by adding weighted filter coefficients to each other and outputs the new filter coefficient to the operation section;
and
an area image discrimination section which determines, on the basis of a pixel value within a pixel block containing a plurality of pixels including a current pixel, whether or not the input image belongs to a text edge area,
wherein the weighting coefficient setting section sets the first coefficient and the second coefficient for performing the filter operation on the input image by the operation section by using the second filter coefficient when the area image discrimination section determines that the input image belongs to a text edge area.

7 more elements

An image processing apparatus performing a digital filter operation process on input image data, comprising:

a first storage section which stores a first filter coefficient used for performing a smoothing process on the input image data;
a second storage section which stores a second filter coefficient used for performing a process different from the smoothing process on the input image data;
a density calculation section which calculates a density of a pixel region including a plurality of pixels of an input image on the basis of a pixel value of the pixel region;
a weighting coefficient setting section which sets, in accordance with the density calculated by the density calculation section, a first coefficient used for weighting the first filter coefficient and a second coefficient used for weighting the second filter coefficient;
an operation section which performs a filter operation on the input image data by using at least the first filter coefficient or the second filter coefficient;
and
a weight process section which weights the first filter coefficient by using the first coefficient set by the weighting coefficient setting section, weights the second filter coefficient by using the second coefficient set by the weighting coefficient setting section, obtains a new filter coefficient by adding weighted filter coefficients to each other and outputs the new filter coefficient to the operation section;
and
wherein the density calculation section calculates the density on the basis of the pixel value of the pixel region of each of a plurality of specific colors, and
the weighting coefficient setting section sets the first coefficient and the second coefficient for performing an identical weight process with respect to the respective specific colors in accordance with the density calculated by the density calculation section.

7 more elements

Dependencies are inferred from the claim text.

Using separate coefficients to weight and add separate images together from a spatial filter process

Life of this patent

Using separate coefficients to weight and add separate images together from a spatial filter process

Life of this patent

Abstract

Claims15