Patent ID: 7305151

Claim:
An image processing apparatus which retrieves a similar image on the basis of a similarity between a reference comparison image serving as a retrieval condition and a target comparison image, comprising: brightness feature information extraction means for extracting brightness feature information on a brightness of an image to be processed; color feature information extraction means for extracting color feature information on a color of the image to be processed; determination means for determining whether color information of the image to be processed is sufficient; comparison means for, when color information of the reference comparison image is sufficient as a result of determination by said determination means, performing a similarity comparison between color feature information of the reference comparison image and color feature information of the target comparison image, and when the color information of the reference comparison image is insufficient, performing a similarity comparison between brightness feature information of the reference comparison image and brightness feature information of the target comparison image; and output means for outputting an image serving as a retrieval result on the basis of a comparison result of said comparison means.