Patent ID: 7567685
Filing Date: 2009-07-28
Classification: G06F,G06K

Abstract:
1. A method for identifying a specific image or a specific audiovisual sequence within a flow of images or audiovisual sequences, and the method comprising the steps of: receiving a stream of digitized image signals representative of the images, and executing an indexing process by a processor, the processor executing the indexing process to calculate for each said digitized image signal, an index appearing in the form of an ordered and finite set of values, thereby digitally encoding the image; calculating a reference index, using the indexing process for the specific image, or extracting reference indexes from the specific audiovisual sequence, so as to form a reference set of said reference indexes, such that said reference indexes that are characteristic of the specific image or of the specific audiovisual sequence are obtained; receiving the index signal and calculating a current index for the current image of the flow, using the indexing process for the current image of the flow; comparing the reference indexes with the current index of the current image of the flow, wherein the indexes appear in the form of ordered and finite sets of values identified, in the reference index and the current index, by a system of coordinates; defining, for a given coordinate of the system of coordinates, a pair of values, of which: calculating a bidimensional histogram of the pairs of values obtained for all the coordinates of the system of coordinates of the reference index and of the current index; calculating a discrete entropy of the bidimensional histogram; calculating a discrete reference marginal entropy of the distribution of the values of the reference index or a discrete current marginal entropy of the current index, wherein the reference marginal entropy or the current marginal entropy is configured to be added to the reference index or the current index, respectively; and calculating a comparison distance between the reference index and the current index, using the reference marginal entropy, the current marginal entropy and the entropy of the bidimensional histogram, wherein a specific image is detected within the flow, using the comparison distance.