Abstract: A method detects an unusual event in a video. Motion vectors are extracted from each frame in a video acquired by a camera of a scene. Zero run-length parameters are determined for each frame from the motion vectors. The zero run-length parameters are summed over predetermined time intervals of the video, and a distance is determined between the sum of the zero run-lengths of a current time interval and the sum of the zero run-lengths of a previous time interval. Then, the unusual event is detected if the distance is greater than a predetermined threshold.

Abstract: A method for generating a representation of multimedia content by first segmenting the multimedia content spatially and temporally to extract objects. Feature extraction is applied to the objects to produce semantic and syntactic attributes, relations, and a containment set of content entities. The content entities are coded to produce directed acyclic graphs of the content entities, where each directed acyclic graph represents a particular interpretation of the multimedia content.

Abstract: A multi-media delivery system for delivering a compressed bitstream through a network to a user device includes a transcoder and a manager. The transcoder is configured to operate on the bit stream using in any one of a plurality of conversion modes. The manager is configured to selecting a particular one of the plurality of conversion modes dependent on semantic content of the bitstream and network characteristics. The system also includes a content classifier to determine the content characteristics, and a model predicator to determine the network characteristics, and user device characteristics. An integrator of the manager generates an optimal rate-quality function to be used for selecting the particular conversion model for a given available bit rate of the network.

Abstract: A method describes activity in a video sequence. The method measures intensity, direction, spatial, and temporal attributes in the video sequence, and the measured attributes are combined in a digital descriptor of the activity of the video sequence.

Abstract: A method measures an intensity of motion activity in a compressed video. The intensity of the motion activity is used to partition the video into segments of equal cumulative motion activity. Key-frames are then selected from each segments. The selected key-frames are concatenated in temporal order to form a summary of the video.

Abstract: In an apparatus for transcoding a compressed video, a generator simulates constraints of a network and constraints of a user device. A classifier is coupled to receive an input compressed video and the constraints. The classifier generates content information from features of the input compressed video. A manager produces a plurality of conversions modes dependent the constraints and content information, and a transcoder produces output compressed videos, one for each of the plurality conversion modes.

Abstract: This invention relates to methods of abrupt scene change detection and fade detection for indexing of MPEG-2 and MPEG-4 compressed video sequences. Abrupt scene change and fade-detection techniques applied to signals in compressed form have reasonable accuracy and the advantage of high simplicity since they are based on entropy decoding and do not require computationally expensive inverse Discrete Cosine Transformation (DCT).

Abstract: A system and method analyzes a compressed video including a sequence of frames. The amount of a dominant feature in each frame of the compressed video is measured. A label is associated with each frame according the measured amount of the dominant feature. Views in the video are identified according to the labels, and the video is segmented into actions according to the views. The video can then be analyzed according to the action to determine significant events in the video.

Abstract: A method locates scene changes in a sequence of images or frames that have been compressed without first decompressing the sequence. The sequence includes subsequences of P-frames between I-frames. DC residual coefficients including sign information are extracted from the sub-sequences of P-frames. If the number of residual coefficients in the P-frames exceed a predetermined threshold, then a scene change is indicated. Positive coefficients indicate fade-ins, and negative coefficients indicate fade-outs.