Patent Document ID: 8169433
Application ID: 12219311

Base Claim:
1. A three-dimensional model retrieval apparatus comprising: at least one processor communicatively coupled with said apparatus including: a model normalizing unit configured to rotate and/or translate a three-dimensional model so that main axis directions of the three-dimensional model are consistent with coordinate axes of a three-dimensional space, and barycenter of the three-dimensional model is consistent with origin of a coordinate system; a two-dimensional image generating unit configured to project said three-dimensional model respectively in a positive direction and a negative direction of each coordinate axis of said coordinate system to generate a plurality of two-dimensional images; a model describing unit configured to generate a model descriptor of the three-dimensional model from said two-dimensional images; and a retrieving unit configured to retrieve, based on said model descriptor, a three-dimensional model which most matches an input query from a model database, and where said model normalizing unit calculates a normal direction of each triangle constituting said three-dimensional model, determines the main axis directions of the three-dimensional model based on distributional information of the normal directions of all triangles, and rotates the three-dimensional model based on the main axis directions, and a weighted distribution matrix of the normal direction is calculated, the matrix is subjected to Eigen-decomposition to obtain three eigenvectors, and the three eigenvector are taken as the main axis directions, and wherein the matrix is represented M = ∑ fCnt ⁢ ⁢ a i * ( p i → - p 0 → ) * ( p i → - p 0 → ) T where {right arrow over (p 0 )} indicates an average value of the normal directions, a i and {right arrow over (p i )} respectively indicating the area and normal direction of each triangle, fCnt indicates a number of triangles contained in the three-dimensional model, and T indicates a transposing operation of the vector.

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Claim 2:
2. The three-dimensional model retrieval apparatus according to claim 1 , wherein said two-dimensional image generating unit projects in positive direction of each coordinate axis only sampling points whose corresponding coordinate positions are positive, and projects in negative direction of each coordinate axis only sampling points whose corresponding coordinate positions are negative, in said projecting.