Patent ID: 7739276

Claim:
A photo retrieval method implemented by a computing device which comprises a category assignor, an expansion retriever, a ranking determiner and a photo arranger, the method comprising: using the category assignor, assigning an object category based on a query; using the expansion retriever, retrieving photos associated with an expanded query term extracted from the query; using the ranking determiner, identifying a category with respect to each retrieved photo by referring to content of each retrieved photo; using the ranking determiner, measuring a level of consistency between the assigned object category and the identified category for each retrieved photo and determining an Image_Score corresponding to each measured level of consistency; using the ranking determiner, assigning a score to each retrieved photo by applying the determined Image_Score and a previously provided weight; using the ranking determiner, determining a ranking of the retrieved photos based on the assigned score; and using the photo arranger, arranging and displaying the photos in response to the determined ranking, wherein, in assigning the score to each retrieved photo, each score s i given to the photo is calculated by satisfying an equation as s i =w ×TF_IDF_Score+(1 −w )×Image_Score in which w is a weight for TF_IDF_Score, wherein: each TF_IDF_Score is a value of modeling a probability that the expanded query term is included in the memo information of the corresponding photo, and Image_Score is a probability that the category exists.