Method and apparatus for shot detection

Claim 3

A method according to claim 1 , wherein generating one or more thresholds comprises: calculating a high threshold that is four- to five-times the calculated average; and calculating a low average that is two- to three-limes the calculated average.

Claim 4

A method according to claim 2 , wherein the high threshold is used to determine whether an abrupt transition has occurred.

Claim 5

A method according to claim 2 , wherein the low threshold is used to indicate whether a gradual transition has occurred, if the histogram difference does not exceed the high threshold.

Claim 6

A method according to claim 4 , further comprising: comparing the histogram difference to the low threshold; accumulating the histogram difference of two or more frames if the histogram difference exceeds the low threshold; and determining that a gradual transition has occurred if the accumulated histogram difference exceeds the high threshold.

Claim 7

A method according to claim 1 , wherein determining a cause of the abrupt transition comprises: calculating a difference in average minimal intensity value between a window of frames preceding the current frame and a window of frames subsequent to the current frame; generating a ratio of the average intensity change of the current frame to the calculated difference in average minimal intensity values; and concluding that the abrupt transition is caused by a flashlight event if the ratio does not exceed a threshold.

Claim 8

A method according to claim 6 , wherein calculating a difference in average minimal intensity values comprises: identifying a window of frames on either side of the current frame; generating an average minimal intensity value for each window from a first and second minimal intensity value of each frame, respectively; and calculating the difference between the generated average minimal intensity values.

Claim 9

A method according to claim 6 , wherein the threshold is equal to one (1), wherein a ratio that deviates from one indicates that the abrupt transition is due to a shot cut, while a ratio close to one indicates that the abrupt transition is due to a flashlight event.

Claim 10

A computer readable medium storing a plurality of executable instructions which, when executed, implement a method according to claim 1 .

Claim 11

A media analysis agent comprising: a shot boundary detector to statistically analyze one or more attributes associated with content in video frames to detect abrupt and gradual transitions in the video content indicative of a shot boundary; and a flashlight detector, responsive to the shot boundary detector, to distinguish abrupt transitions in the video content caused by flashlight events from those caused by actual shot boundaries, to reduce false-positive identification of flashlight events as shot boundaries; and an adaptive threshold selection module, responsive to the shot boundary detector, to dynamically set one or more thresholds for use in shot boundary identification based, at least in part, on one or more attributes of video content, wherein the adaptive threshold selection module calculates an average and standard deviation of a histogram difference in a sliding window of frames surrounding the current frame, and generates a proposed low threshold value (Ts) and a proposed high threshold value (Tb) from the average histogram difference, and wherein the proposed low threshold is two- to three-times the calculated average histogram difference, while the proposed high threshold is four- to five-times the calculated average histogram difference.

Claim 12

A media analysis agent comprising: a shot boundary detector to statistically analyze one or more attributes associated with content in video frames to detect abrupt and gradual transitions in the video content indicative of a shot boundary; and a flashlight detector, responsive to the shot boundary detector, to distinguish abrupt transitions in the video content caused by flashlight events from those caused by actual shot boundaries, to reduce false-positive identification of flashlight events as shot boundaries; and an adaptive threshold selection module, responsive to the shot boundary detector, to dynamically set one or more thresholds for use in shot boundary identification based, at least in part, on one or more attributes of video content, wherein the adaptive threshold selection module calculates an average and standard deviation of a histogram difference in a sliding window of frames surrounding the current frame, and generates a proposed low threshold value (Ts) and a proposed high threshold value (Tb) from the average histogram difference, and wherein the proposed low threshold is two- to three-times the calculated average histogram difference, while the proposed high threshold is four- to five-times the calculated average histogram difference.

Claim 13

A media analysis agent according to claim 10 , wherein the adaptive threshold selection module certifies the proposed thresholds if the calculated standard deviation does not reach a standard deviation threshold.

Claim 14

A media analysis agent according to claim 11 , wherein if the adaptive threshold selection module cannot certify the proposed thresholds, prior thresholds are used by shot boundary detector.

Claim 15

A media analysis agent according to claim 10 , wherein the high threshold is used to identity an abrupt transition, while the low threshold is used to indicate a potential gradual transition.

Claim 16

A media analysis agent according to claim 13 , wherein shot boundary detector compares the histogram difference to a low threshold if the difference does not exceed the high threshold, and accumulates the histogram differences of frames wherein the difference exceeds the low threshold.

Claim 17

A media analysis agent according to claim 14 , wherein shot boundary detector identifies a gradual transition when the accumulated histogram differences exceed the high threshold.

Claim 18

A media analysis agent according to claim 10 , wherein the shot boundary detector calculates a difference in light intensity histograms between a current frame and a preceding frame, and compares the histogram difference to a dynamically determined threshold, wherein an abrupt transition is identified by a histogram difference that exceeds the threshold.

Claim 19

A media analysis agent according to claim 16 , wherein shot boundary detector invokes an instance of flashlight detector to determine whether the abrupt transition is the result of a flashlight event.

Claim 20

A media analysis agent according to claim 10 , wherein flashlight detector calculates a difference in average minimal intensity values between a first sliding window preceding the current frame, and a second sliding window subsequent to the current frame.

Claim 21

A media analysis agent according to claim 18 , wherein flashlight detector calculates the average intensity change of the current frame, and generates a ratio of the difference in average minimal intensity values to the average intensity change of the current frame.

Claim 22

A media analysis agent according to claim 19 , wherein flashlight detector determines that the abrupt change was due to a flashlight event if the ratio does not exceed a threshold value.

Claim 23

A media analysis agent according to claim 20 , wherein the threshold value is one (1).

Claim 24

A media analysis agent according to claim 20 , wherein the flashlight detector concludes that the abrupt transition was caused by a shot boundary if the ratio exceeds the threshold value.

Claim 25

A computing system comprising: a memory, to receive media content; and a media processing system, coupled to the memory device, including a media analysis agent according to claim 10 to segment the received media content into uniquely identifiable shots.

Claim 26

One or more computer-readable media having stored thereon a computer program that, when executed by one or more processors, causes the one or more processors to; calculate a difference in light intensity histograms between two frames; compare the histogram difference to a dynamically determine threshold, wherein an abrupt transition is indicated if the histogram difference exceeds the threshold, wherein to determine the dynamic threshold, the one or more processors: calculate an average and standard deviation value of the histogram difference in a sliding window of frames; generate one or more thresholds as multiples of the calculated average; and determine whether the calculated standard deviation falls below a standard deviation threshold before adopting the generated one or more thresholds; and determine whether the abrupt transition was caused by a shot boundary between the two frames or by a flashlight event.

Claim 27

One or more computer-readable media having stored thereon a computer program that, when executed by one or more processors, causes the one or more processors to; calculate a difference in light intensity histograms between two frames; compare the histogram difference to a dynamically determine threshold, wherein an abrupt transition is indicated if the histogram difference exceeds the threshold, wherein to determine the dynamic threshold, the one or more processors: calculate an average and standard deviation value of the histogram difference in a sliding window of frames; generate one or more thresholds as multiples of the calculated average; and determine whether the calculated standard deviation falls below a standard deviation threshold before adopting the generated one or more thresholds; and determine whether the abrupt transition was caused by a shot boundary between the two frames or by a flashlight event.

Claim 28

One or more computer-readable media as recited in claim 24 wherein to determine a cause of the abrupt transition, the one or more processors: calculate a difference in average minimal intensity values between a window of frames preceding the current frame and a window of frames subsequent to the current frame; generate a ratio of the average intensity change of the current frame to the calculated difference in average minimal intensity values; and conclude that the abrupt transition is caused by a flashlight event if the ratio does not exceed a threshold.

Claim 29

One or more computer-readable media as recited in claim 25 wherein the threshold is equal to one, wherein a ration that deviates from one indicates that the abrupt transition is due to a shot cut, while a ratio close to one indicates that the abrupt transition is due to a flashlight event.