Keyframe selection to represent a video

Claim 3

The method of claim 1 wherein the selected portion of the set of images is based on the minimum size face to be detected.

Claim 4

The method as claimed in claim 1 wherein the images are smaller by the same scale factor.

Claim 5

The method as claimed in claim 3 further comprising the step of: selecting the scale factor dependent on the size of the frame.

Claim 6

The method as claimed in claim 1 further comprising the step of: tracking overlap of a detected face in consecutive frames in order to filter detected faces which are not likely to be valid.

Claim 7

The method as claimed in claim 1 wherein the step of selecting a most interesting shot includes providing a shot score based on a set of measures selected from the group consisting of motion between frames, amount of skin color pixels, shot length and detected faces.

Claim 8

The method as claimed in claim 6 wherein each measure includes a respective weighting factor.

Claim 9

The method as claimed in claim 7 wherein the weighting factor is dependent on the level of confidence of the measure.

Claim 10

The method as claimed in claim 1 wherein the step of performing face detection uses a neural network-based algorithm.

Claim 13

The apparatus as claimed in claim 10 wherein the selected portion of the set of images is based on the minimum size face to be detected.

Claim 14

The apparatus as claimed in claim 10 wherein the images are smaller by the same scale factor.

Claim 15

The apparatus as claimed in claim 12 further comprising: means for selecting the scale factor dependent on the size of the frame.

Claim 16

The apparatus as claimed in claim 10 further comprising: means for tracking overlap of a detected face in consecutive frames to filter detected faces which are not likely to be valid.

Claim 17

The apparatus as claimed in claim 10 wherein the means for selecting a most interesting shot comprises: means for providing a shot score based on a set of measures selected from the group consisting of motion between frames, amount of skin color pixels, shot length and detected faces.

Claim 18

The apparatus as claimed in claim 15 wherein each measure includes a respective weighting factor.

Claim 19

The apparatus as claimed in claim 16 wherein the weighting factor is dependent on the level of confidence of the measure.

Claim 20

The apparatus as claimed in claim 10 wherein the means for performing face detection uses a neural network-based algorithm.

Claim 23

The apparatus as claimed in claim 19 wherein the selected portion of the set of images is based on the size of the face to be detected.

Claim 24

The apparatus as claimed in claim 19 wherein the images are smaller by the same scale factor.

Claim 25

The apparatus as claimed in claim 21 further comprising: a frame sampler which selects the scale factor dependent on the size of the frame.

Claim 26

The apparatus as claimed in claim 19 further comprising: a face tracker which tracks a detected face through consecutive frames to filter detected faces which are not likely to be valid.

Claim 27

The apparatus as claimed in claim 19 wherein the key shot detector comprises: a shot score generator which generates a shot score for based on a set of measures selected from the group consisting of motion between frames, amount of skin color pixels, shot length and detected faces.

Claim 28

The apparatus as claimed in claim 24 wherein each measure includes a respective weighting factor.

Claim 29

The apparatus as claimed in claim 25 wherein the weighting factor is dependent on the level of confidence of the measure.

Claim 30

The apparatus as claimed in claim 19 wherein the face detector uses a neural network-based algorithm.

Claim 31

A computer system comprising: a memory system storing a sequence of frames; and a face detector which performs face detection in the sequence of frames, the face detector comprising: an image creator which creates a set of images for the frame with each image in the set of images smaller than the previous image; and a face searcher which searches for faces having at least a minimum size in a selected portion of the set of images; a shot boundary detector which detects shot boundaries to identify shots within the detected shot boundaries; and a key shot selector which selects a most interesting shot from the identified shots based on a number of detected faces in the shot; and a key frame selector which selects the single representative key frame representative of the sequence of frames from the selected shot based on a number of detected faces in the frame.

Claim 32

A computer system comprising: a memory system storing a sequence of frames; and a face detector which performs face detection in the sequence of frames, the face detector comprising: an image creator which creates a set of images for the frame with each image in the set of images smaller than the previous image; and a face searcher which searches for faces having at least a minimum size in a selected portion of the set of images; a shot boundary detector which detects shot boundaries to identify shots within the detected shot boundaries; and a key shot selector which selects a most interesting shot from the identified shots based on a number of detected faces in the shot; and a key frame selector which selects the single representative key frame representative of the sequence of frames from the selected shot based on a number of detected faces in the frame.

Claim 33

An article of manufacture comprising: a computer-readable medium for use in a computer having a memory; a computer-implementable software program recorded on the medium for extracting a single representative key frame from a sequence of frames, the sequence of frames including a plurality of shots, the computer implemented software program comprising instructions for: performing face detection in the sequence of frames comprising the steps of: creating a set of images for each frame in the sequence of frames with each image in the set of images smaller than the previous image; and searching for faces having at least a minimum size in a selected portion of the set of images; detecting shot boundaries in the sequence of frames to identify shots within the detected shot boundaries; selecting a most interesting shot from the identified shots based on a number of detected faces in the shot; and selecting the single representative key frame representative of the sequence of frames from the selected shot based on a number of detected faces in the frame.

Claim 34

An article of manufacture comprising: a computer-readable medium for use in a computer having a memory; a computer-implementable software program recorded on the medium for extracting a single representative key frame from a sequence of frames, the sequence of frames including a plurality of shots, the computer implemented software program comprising instructions for: performing face detection in the sequence of frames comprising the steps of: creating a set of images for each frame in the sequence of frames with each image in the set of images smaller than the previous image; and searching for faces having at least a minimum size in a selected portion of the set of images; detecting shot boundaries in the sequence of frames to identify shots within the detected shot boundaries; selecting a most interesting shot from the identified shots based on a number of detected faces in the shot; and selecting the single representative key frame representative of the sequence of frames from the selected shot based on a number of detected faces in the frame.