Video signature creation and matching

A method comprising:

• retrieving, from a memory, data of a video frame, the data including a plurality of measurements of luminance, each of the measurements of luminance being associated with a different entry in a matrix;
• weighting each one of the measurements of luminance according to a row position of the one measurement of luminance in the matrix;
• calculating a weighted average luminance value, Ly, for the weighted measurements of luminance weighted according to the row position;
• weighting each one of the measurements of luminance according to a column position of the one measurement of luminance in the matrix;
• calculating a weighted average luminance value, Lx, for the weighted measurements of luminance weighted according to the column position;
• creating a video signature, SN, of the video frame, the video signature, SN, including the weighted average luminance value Ly and the weighted average luminance value, Lx;
• dividing the data of the video frame into a plurality of sets of measurements of luminance corresponding to a plurality of different regions, R, of the video frame, each of the sets being associated with a different sub-matrix of the matrix;
• and
• for each one of the sets of measurements of luminance:
• calculating a weighted average luminance value, Lx(R), for the measurements of luminance in the one set such that each one of the measurements of luminance is weighted according to a row position of the one measurement of luminance in the sub-matrix of the one set;
• calculating a weighted average luminance value, Ly(R), for the measurements of luminance in the one set such that each one of the measurements of luminance is weighted according to a column position of the one measurement of luminance in the sub-matrix of the one-set;
• and
• appending to the video signature, SN, of the video frame, the weighted average luminance value, Ly(R), of the one set and the weighted average luminance value, Lx(R), of the one set.

A system comprising a processor;

• and a memory to store data used by the processor, wherein the processor is operative to:
• retrieve, from the memory, a video signature, S0, the video signature, S0, including at least one first average luminance value of a video frame and a plurality of second weighted average luminance values of a plurality of different regions, R, of the video frame;
• determine a subset of a plurality of video signatures, Si, which match the at least one first average luminance value of the video signature, S0 according to a matching criteria;
• and
• compare the plurality of the second weighted average luminance values to the subset of the video signatures, Si, to try to find one of the video signatures, Si, in the subset which fulfills a matching criteria, wherein:
• the at least one first average luminance value of the video signature, S0, includes a weighted average luminance value, Lx, and a weighted average luminance value, Ly;
• each of the plurality of video signatures, Si, includes a weighted average luminance value, Lxi, and a weighted average luminance value, Lyi;
• the processor is operative to compare:
• the weighted average luminance value Lx to the weighted average luminance value Lxi of each of the plurality of video signatures, Si;
• and the weighted average luminance value Ly to the weighted average luminance value Lyi of each of the plurality of video signatures Si;
• and
• the processor is operative to determine the subset of video signatures Si to include the ones of the video signatures Si having:
• (a) the weighted average luminance value Lxi within a first limit of the weighted average luminance value Lx of the video signature S0;
• and (b) the weighted average luminance value Lyi within a second limit of the weighted average luminance value Ly of the video signature S0.