Patent ID: 6941323

Claim:
A method of retrieving one or more digital images or portions of digital images comprising: providing a query image; processing said query image with one or more filters so as to modify pixel values in said query image and to distinguish at least one set of filtered object pixels from background pixels in said query image, wherein said filters include at least one of a look-up table filter, a filter which sharpens small scale features within a distinguished object, and a shading correction filter, wherein a shape defined by said distinguished filtered object pixels depends on said filters, wherein intensity values of said filtered object pixels also depend on said filters, and wherein the visual characteristics of an object which are related to object characterization are enhanced by said filters; calculating a single object characterization parameter using as at least one set of inputs either (1) the intensity values of substantially all and substantially only said filtered object pixels, (2) the relative position of at least some object pixels on the perimeter of said distinguished object, or (3) the total number of distinguished object pixels; assigning an object characterization parameter set comprising said object characterization parameter to at least one set of said filtered object pixels in said query image; comparing said object characterization parameter set with one or more additional object characterization parameter sets associated with sets of object pixels defined in images in an image database or with other sets of object pixels defined within said query image; and selecting one or more sets of object pixels, clusters of sets of object pixels, or images in response to said comparing.