Image retrieval method and apparatus independent of illumination change

A computer readable medium having embodied therein a computer program for performing the a method of extracting illumination invariant color from an image comprising:

• inputting an image;
• representing the image as an illumination invariant image by converting an illumination of the image into a standard illumination corresponding to 6500K on the daylight locus;
• and
• extracting color information from the illumination invariant image by using one among a plurality of color descriptors including a dominant color descriptor, a scalable color descriptor, a color layout descriptor and a color structure descriptor.

An apparatus for extracting illumination invariant color from an image, comprising:

• an image input unit which inputs an image;
• a standard illumination color converting unit which represents the image as an illumination invariant image by converting an illumination of the image into a standard illumination corresponding to 6500K on the daylight locus;
• and
• a color information extracting unit which extracts color information from the illumination invariant image by using one among a plurality of color descriptors including a dominant color descriptor, a scalable color descriptor, a color layout descriptor and a color structure descriptor.

A method of representing illumination invariant color extracted from an image, comprising:

• arranging a color descriptor type corresponding to one among a plurality of color descriptors including a dominant color descriptor, a scalable color descriptor, a color layout descriptor and a color structure descriptor, the color descriptor type being used to extract color information from an illumination invariant image obtained by converting an illumination of the image into a standard illumination and the color descriptor type being represented as a first plurality of bits;
• arranging a size of the color information extracted from the illumination invariant image by using the color descriptor type, the size of the color information being represented as a second plurality of bits;
• and
• arranging the color information extracted from the illumination invariant image by using the color descriptor type.

A standard illumination color converting method comprising:

• removing low luminance parts and self luminance parts from an input query image;
• detecting an illumination color of the image from the remaining pixels after the removal of the low luminance parts and self luminance parts;
• and
• converting the detected illumination color into a standard illumination color.

A computer readable medium having embodied therein a computer program for performing the a standard illumination color converting method comprising:

• removing low luminance parts and self luminance parts from an input query image;
• detecting an illumination color of the image from the remaining pixels after the removal of the low luminance parts and self luminance parts;
• and
• converting the detected illumination color into a standard illumination color.