Patent ID: 8787682

Claim:
A method to categorize images, comprising: detecting local features for each image; applying a tree structure to index local features in the images; extracting a rank list of candidate images with category tags based on a tree indexing structure to estimate a label of a query image, and determining a category of the query image C(q) by C ⁡ ( q ) = arg ⁢ ⁢ max N c = 1 ⁢ ∑ i = 1 K ⁢ ⁢ 1 ⁢ ( C ⁡ ( I i ) = c ) i , where retrieved top K candidate images I i are sorted according to matching score s i in descending order {I i ,s i } 1 K , s i >s j , ∀i<j and where C(I i ) is an image category index of I i ι. wherein the above steps are computer implemented.