Patent Document ID: 9075846
Application ID: 13712773

Base Claim:
1. A computer-implemented method for retrieval of Arabic historical manuscripts, comprising the steps of: entering Arabic historical manuscript images into a computer for processing; extracting circular polar grid features from the Arabic historical manuscript images stored in the computer, wherein the step of extracting circular polar grid features comprises: building a circular polar grid from a multiline-axis including an intersection of a 0° line, a 45° line, a 90° line and a 135° line; overlaying concentric circles centered about the intersection point of said multiline-axis, the concentric circles having radial values of r, 2r, 3r, . . . nr; and centering said circular polar grid at a centroid of an image term to be indexed; constructing a Latent Semantic Index based on the extracted circular polar grid features, the Latent Semantic Index having a reduced dimension m×n Term-by-Document matrix obtained from a Singular Value Decomposition of a higher dimensional Term-by-Document matrix constructed by the computer from the extracted circular polar grid features, wherein m rows represent the features and n columns represent the images; accepting a user query against the stored Arabic historical manuscript images, the computer forming the user query as a query vector derived from features extraction of a query image supplied by the user; performing query matching based on comparison between the query vector and the Term-by-Document matrix; weighing each term of said Term-by-Document matrix by a value representing an occurrence frequency of a feature of said term in said document, wherein the step of weighing each term of said Term-by-Document matrix comprises: picking a comprehensive training set of said document for each said feature; calculating a mean μ f and a standard deviation σ f of the features f's value across the training set; and for each image in the collection, defining an occurrence count O fj of feature f according to the relation: O fj = { ⌈ val fj - μ f σ f ⌉ if ⁢ ⁢ val fj > μ f 0 otherwise where val fj is the value of the feature f in image j; and displaying Arabic historical document images returned by the query matching process performed by the computer, the returned document images being ranked by similarity to the user query according to a predetermined distance measurement between the query vector and the Term-by-Document matrix, wherein the computer determines a plurality of image features defined by a count of black image pixels found in regions of intersection between said multilines and said concentric circles.

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Claim 5:
5. The computer-implemented method according to claim 1 , further comprising preprocessing steps adapted for enhancing efficiency of said circular polar grid features extraction step.