Patent ID: 8311368
Filing Date: 2012-11-13
Classification: G06F,G06K

Abstract:
1. An image-processing apparatus, comprising: an extraction unit configured to extract a plurality of characteristic points from a group of images including reduced images of an input query image; a characteristic-amount computation unit configured to respectively compute fluctuated characteristic amounts for the plurality of characteristic points from the group of images after a prescribed alteration is performed to the group of images; an evaluation unit configured to evaluate a fluctuated characteristic amount among the fluctuated characteristic amounts for the plurality of characteristic points in the group of images computed by the characteristic-amount computation unit; a selection unit configured to select at least one characteristic point according to a fluctuated characteristic amount that is evaluated by the evaluation unit to be less than or equal to a threshold value from the plurality of characteristic points in the group of images to use for image retrieval; and a retrieval unit configured to retrieve an image from among a plurality of stored images using at least one characteristic point in the group of images selected by the selection unit, wherein each fluctuated characteristic amount is an amount of fluctuation of a characteristic amount of the corresponding characteristic point after the prescribed alteration is performed to the respective image, and wherein for each characteristic point, a first characteristic amount is calculated for the characteristic point, the prescribed alteration is performed to the respective image, a second characteristic amount is calculated for the characteristic point in the image after the prescribed alteration is performed, and the fluctuated characteristic amount for the characteristic point is computed based on the first characteristic amount and the second characteristic amount.