Color discrimination apparatus and method

A color discriminating apparatus comprising:

• a calculator which calculates normalized data x(i) of image data X(i) (i=1,2, . . . n) for each of a plurality of color components in accordance with the equation:
• x(i)=X(i)k/{X(1)k+X(2)k+ . . . X(n)k}(k≧2),
• the image data X(i)(i=1,2, . . . n) including color image data for n color components of an image;
• and
• a color discriminator that discriminates the presence or absence of the color within the n color components of the color image based on calculated normalized data.

A color discriminating apparatus comprising:

• a luminance information calculator which calculates luminance information of each part of a color image based on image data of a plurality of color components in each of the parts of the color image;
• a color discriminator which discriminates the presence or absence of a discriminated color in each part of the color image by comparing calculated luminance information for each part with a discrimination reference;
• an area information generator that generates area information related to a geometrical configuration of the color image;
• and
• a changer which changes the discrimination reference based on generated area information.

A color discriminating apparatus comprising:

• a color discriminator which discriminates a predominant color for each of a selected image section and a plurality of surrounding image sections in a color image based on image data of each of a plurality of color components;
• a color dispersion degree calculator which calculates a degree of color dispersion for the selected image section using the predominant color of the selected image section and of the plurality of surrounding image sections;
• a color dispersion degree discriminator which discriminates whether the degree of color dispersion is larger than a predetermined value;
• and
• a black allocator which allocates the color of black to the selected image section when the color dispersion degree is discriminated to be larger than the predetermined value.

A method for discriminating the color of a color image, comprising the steps of:

• calculating luminance information of the color image based on image data of the color image including a plurality of color components;
• calculating color information of the color image based on the image data;
• discriminating, based on the color information, whether the color image is chromatic or achromatic;
• discriminating, based on the luminance information, whether the color image is black or white when the color image is discriminated to be achromatic;
• and
• discriminating, based on the color information and the luminance information, which of a plurality of predetermined colors corresponds with the color image when the color image is discriminated to be chromatic.

A method for discriminating the color of a color image, comprising the steps of:

• calculating normalized data x(i) of image data X(i) (i=1,2, . . . n) for each of a plurality of color components in accordance with the equation:
• x(i)=X(i)k/{X(1)k+X(2)k+ . . . X(n)k}(k≧2),
• the image data X(i)(i=1,2, . . . n) including color image data for n color components of the color image;
• and
• discriminating the color of the color image based on calculated normalized data.

A method for discriminating the color of a color image, comprising the steps of:

• calculating luminance information of each part of the color image based on image data of a plurality of color components in each part of the color image;
• discriminating the presence or absence of a discriminated color in each part of of the color image by comparing calculated luminance information for each part with a discrimination reference;
• generating area information related to a geometrical configuration of the color image;
• and
• changing the discrimination reference based on generated area information.

A method for discriminating the color of color image, comprising the steps of:

• discriminating a predominant color for each of a selected image section and a plurality of surrounding image sections in the color image based on image data of each of a plurality of color components constituting the selected image section and the plurality of surrounding image sections;
• calculating a degree of color dispersion for the selected image section using the predominant color of the selected image section and of the plurality of surrounding image sections;
• discriminating whether the degree of color dispersion is larger than a predetermined value;
• and
• allocating the color of black to the selected image section when the color dispersion degree is discriminated to be larger than the predetermined value.

A color allocating apparatus comprising:

• a calculator which calculates a value x(i) (i=1,2, . . . , n) which is standardized for each of color components with respect to each of the pixels according to the following expression based on image data which is represented in terms of a plurality of color component values X(i) (i=1, 2, . . . , n) with respect to each of the pixels:
• x(i)=X(i)k/{X(i)k+X(2)k+ . . . +X(n)k}(k≧2),
• and
• an allocator which allocates one of predetermined colors with respect to each of the pixels based on the calculated standardized value x(i).

A color allocating apparatus comprising:

• a configuration discriminator which discriminates whether a part constituting a color image is configured by a bold line having a width not smaller than a predetermined reference value or a thin line having a width smaller than the predetermined reference value;
• a color discriminator which discriminates whether color of a pixel is white, black, or chromatic color according to a threshold value of the discriminated part based on a predetermined threshold value;
• and
• an adjuster which changes the threshold value for discrimination by the color discriminator according to the configuration discriminated by the configuration discriminator.

A color allocating apparatus comprising:

• an allocator which allocates an allocated color from one of a predetermined plurality of colors that is close to the color of a pixel for each pixel of a color image;
• a calculator which calculates a variation degree of the allocated color in a partial area composing a plurality of pixels in the color image;
• and
• a re-allocator which reallocates the color of a target pixel corresponding to the partial area to black when it is judged that the variation degree is large.