Abstract: In one implementation, a plurality of signature vectors from a multi-dimensional representation of a graphical object is generated. Each of the signature vectors comprises attributes that vary little in response to changes in shape, size, orientation, and visual layer appearance of the graphical object, and each of the signature vectors includes attributes based on operations of integration, differentiation, and transforms on the multi-dimensional representation of the graphical object. Each signature vector is composited into multiple portions from the plurality of signature vectors to define an appearance-invariant signature of the graphical object.

Abstract: A method comprising: mapping an image onto multiple level sets connected by multiple branches, wherein each of said level sets corresponds to a predefined range of values for an attribute of said image; associating multiple pixels of said image to said multiple level sets in accordance with the value of each pixel; identifying a source level set associated with a source pixel of said multiple pixels; for each of said multiple pixels, determining that a distance between said source pixel and one of said multiple pixels is within a predefined threshold, wherein said distance is calculated as a function of a first distance between said source level set and said level set associated with said one of said multiple pixels; in one embodiment, the determined distance is applied to an image processing application to produce a processed image, and the processed image is rendered on a rendering medium.

Abstract: A method comprising: mapping an image onto multiple level sets connected by multiple branches, wherein each of said level sets corresponds to a predefined range of values for an attribute of said image; associating multiple pixels of said image to said multiple level sets in accordance with the value of each pixel; identifying a source level set associated with a source pixel of said multiple pixels; for each of said multiple pixels, determining that a distance between said source pixel and one of said multiple pixels is within a predefined threshold, wherein said distance is calculated as a function of a first distance between said source level set and said level set associated with said one of said multiple pixels; in one embodiment, the determined distance is applied to an image processing application to produce a processed image, and the processed image is rendered on a rendering medium.

Abstract: In one implementation, a plurality of signature vectors from a multi-dimensional representation of a graphical object is generated. Each of the signature vectors comprises attributes that vary little in response to changes in shape, size, orientation, and visual layer appearance of the graphical object, and each of the signature vectors includes attributes based on operations of integration, differentiation, and transforms on the multi-dimensional representation of the graphical object. Each signature vector is composited into multiple portions from the plurality of signature vectors to define an appearance-invariant signature of the graphical object.

Abstract: In one implementation, a graphical object classification system includes an acquisition module, a signature generation module, and a classification module. The acquisition module accesses a representation of a graphical object. The signature generation module generates an appearance-invariant signature of the graphical object based on the representation. The classification module classifies the graphical object based on the appearance-invariant signature.

Abstract: A method of determining correspondence between non-planar surfaces is disclosed. The method comprises calculating, for each surface, a spectral representation based on an eigenbasis of at least a portion of the surface; calculating a mapping matrix, based on the spectral representations; and determining the correspondence between the non-planar surfaces, based on the mapping matrix and the eigenbases.

Abstract: In one implementation, a graphical object classification system includes an acquisition module, a signature generation module, and a classification module. The acquisition module accesses a representation of a graphical object. The signature generation module generates an appearance-invariant signature of the graphical object based on the representation. The classification module classifies the graphical object based on the appearance-invariant signature.