摘要:
An apparatus for detecting an action in a test video. In an illustrative embodiment, the apparatus includes a first mechanism for receiving a query for a particular action via a query video. A second mechanism employs motion vectors associated with the test video to compute one or more motion-similarity values. The one or more motion-similarity values represent motion similarity between a first group of pixels in a first frame of a query video and a second group of pixels in a second frame of the test video based on the motion vectors. A third mechanism uses the one or more similarity values to search for the particular action or similar action in the test video. In a more specific embodiment, another mechanism aggregates the similarity values over a predetermined number of frames to facilitate estimating where the particular action or version thereof occurs or is likely to occur in the test video.
摘要:
Multimedia information communicated between a transmitter and a receiver may be transcoded by intercepting the multimedia information within a network communication system. The available transmission rate of the downlink channel may be estimated by, for example, calculating a ratio of the smoothed round trip time of packets communicated to the receiver and a smoothed congestion window associated with the downlink channel. If the transmission rate at which the multimedia information is encoded is greater than the available transmission rate, the multimedia information may be transcoded to conform the multimedia information to the available transmission rate. The transcoded multimedia information may then be transmitted to the receiver over the downlink channel using a transmission timer.
摘要:
Encoding digital data by using cues at a decoder. An encoder selects an index to indicate a target codeword from the complete space of all codewords to a decoder. The index identifies a group or a set of codewords that contain the target codeword. The sets are represented by a bit-length that is smaller than the code word bit-length thus achieving compression. Two or more codewords in such a set are separated by a predetermined distance and all such sets of codewords considered together form the complete space of all codewords. The encoder sends syntax information, including the index, to specify the decoding. The decoder then uses a set of candidate cues in a comparison operation to determine the target codeword from the indexed set. Processing complexity can be allocated among the encoder, decoder and other possible devices as, for example, in a digital network.
摘要:
Optimum bit rates and power levels are determined for subchannels in multicarrier communication systems. A tangent of the rate-power curve has a slope &lgr;. The slope is defined by the quotient difference between high/low power and high/low rate. A particular &lgr; is evaluated to find its corresponding total power followed by an update of &lgr;, in the form of an increase or decrease, to get closer to the optimal solution. Each &lgr; is evaluated to find the optimal operating point for each subchannel on the rate-power curve by summing the power allocated to the subchannels, and comparing the result to the power budget. Look-up tables are stored for individual channels, but similarity between channels permits joint use of look-up tables by multiple channels. The tables are used to determine the rate-power characteristics at each iteration. An optimal solution is found when either a newly chosen power allocation meets the power budget exactly or a newly chosen power budget equals the high or low power of a previous iteration.