Image processing apparatus and method for detecting a background color based on data chrominance distribution

An image processing apparatus that detects a background color of a document based on image data of a colormetric system in which a brightness component and a color component are separated, comprising:

• a processor programmed to control:
• an element counting unit that divides a color plane defining a color component into a plurality of color areas, and counts a number of elements of the image data belonging to each of the plurality of color areas;
• a single area evaluation unit that extracts a color area in which the number of elements of the image data exceeds a first threshold value, and gives a positive evaluation to the extracted color area;
• a multiple area element calculating unit that calculates the number of elements of the image data belonging to each area of a multiple area constituted of mutually adjacent color areas of the plurality of color areas, based on the number of elements counted by the element counting unit;
• a multiple area evaluation unit that extracts a multiple area in which the number of elements of the image data exceeds a second threshold value, and gives a positive evaluation to each color area included in the extracted multiple area;
• and
• a color area specifying unit that specifies a color area to which a positive evaluation is given by both the single area evaluation unit and the multiple area evaluation unit, as the color area of background color.

An image processing apparatus that detects a background color of a document based on image data of a colormetric system in which a brightness component and a color component are separated, comprising:

• a processor programmed to control:
• means for dividing a color plane defining the color component into a plurality of color areas, and counting a number of elements of the image data belonging to each of the plurality of color areas;
• means for extracting a color area in which the number of elements of the image data exceeds a first threshold value and giving a positive evaluation to the extracted color area;
• means for specifying a multiple area as an area constituted of mutually adjacent color areas of the plurality of color areas;
• means for counting the number of elements of the image data belonging to each area of the multiple area;
• means for extracting a multiple area in which the number of elements of the image data exceeds a second threshold value and giving a positive evaluation to the plurality of color areas included in the extracted multiple area;
• and
• means for specifying a color area to which the positive evaluation is given by the means for extracting the color area and the means for extracting the multiple area as a color area of background color.

An image processing apparatus that detects a background color of a document based on image data of a colormetric system in which a brightness component and a color component are separated, comprising:

• a processor programmed to control:
• means for dividing a color plane defining the color component into a plurality of color areas, and counting a number of elements of the image data belonging to each of the plurality of color areas;
• means for extracting a color area in which the number of elements of the image data exceeds a first threshold value and giving a positive evaluation to the extracted color area;
• means for calculating the number of elements of the image data belonging to each area of a multiple area constituted of mutually adjacent color areas of the plurality of color areas, based on the number of elements counted by an element counting unit;
• means for extracting a multiple area in which the number of elements of the image data exceeds a second threshold value, and giving a positive evaluation to the plurality of color areas included in the extracted multiple area;
• and
• means for specifying the color area to which the positive evaluation is given by the means for extracting the color area and the means for extracting the multiple area as a color area of background color.

A method of detecting a background color of a document based on image data of a colormetric system in which a brightness component and a color component are separated, comprising the steps of:

• dividing a color plane defining the color component into a plurality of color areas, and counting a first number of elements of the image data belonging to each color area of the plurality of color areas;
• counting a second number of elements of the image data belonging to each area of a multiple area constituted of mutually adjacent color areas of the plurality of color areas;
• extracting a color area in which the first number of elements of the image data exceeds a first threshold value, and giving a positive evaluation to the extracted color area;
• extracting a multiple area in which the second number of elements of the image data exceeds a second threshold value and giving a positive evaluation to each color area included in the extracted multiple area;
• and
• specifying a color area receiving a positive evaluation both individually and as part of a multiple area as a color area of background color.

A method of detecting a background color of a document based on image data of a colormetric system in which a brightness component and a color component are separated, including the steps of:

• dividing a color plane defining the color component into a plurality of color areas and counting a first number of elements of the image data belonging to each color area of the plurality of color areas;
• calculating a second number of elements of the image data belonging to each area of a multiple area constituted of mutually adjacent color areas of the plurality of color areas, based on the counted number of elements;
• and
• extracting a color area in which the first number of elements of the image data exceeds a first threshold value and giving a positive evaluation to the extracted color area;
• extracting a multiple area in which the second number of elements of the image data exceeds a second threshold value, and giving a positive evaluation to each color area included in the extracted multiple area;
• and
• specifying a color area receiving a positive evaluation both individually and as part of a multiple area as a color area of background color.