Inter frame

About: Inter frame is a research topic. Over the lifetime, 4154 publications have been published within this topic receiving 63549 citations.

Dynamic frame-skipping in video transcoding

Abstract: This paper investigates the dynamic frame skipping strategy in video transcoding. To speed up the operation, a video transcoder usually reuses the decoded motion vectors to reencode the video sequences at a lower bit-rate. When frame skipping is allowed in a transcoder, those motion vectors can not be reused because the motion vectors of the current frame is no longer estimated from the immediate past frame. To reduce the computational complexity of motion vectors reestimation, a bilinear interpolation approach is developed to overcome this problem. Based on these interpolated motion vectors, the search range can be much reduced. Furthermore, we propose a frame rate control scheme which can dynamically adjust the number of skipped frames according to the accumulated magnitude of the motion vectors. As a result, the decoded sequence can present much smoother motion.

Apparatus and method for detecting motion in a video signal

Abstract: A system detects motion in a video signal by identifying differences between a current image frame and a reference image frame. A difference profile is calculated that represents the differences between the current image frame and the reference image frame. A motion detection signal is generated by the system if the difference profile exceeds a threshold. In one configuration, the system replaces the reference image frame with each successive current image frame. In other configurations, the system replaces the reference image frame with the current image frame if the difference profile exceeds the threshold. The system generates difference data associated with the differences between the current image frame and the reference image frame. This difference data can be partitioned into multiple blocks. An average value is calculated for each block of difference data. Upon generation of a motion detection signal, the system may be configured to record the current image frame if the difference profile exceeds the threshold.

Motion-compensated interframe coding system

Abstract: An interframe coding system provided for highly efficient transmission of coded television picture signal is improved by compensating prediction error of predicted picture motion in response to interframe correlation detected by shifting moving blocks in a direction opposite to a motion vector detected for predicting interframe picture motion in order to reduce an amount of coded signals to be transmitted, and further improved regarding the detection of motion vector by examining interframe correlation referred to accumulated logarithms of absolute values of interframe differential picture element signals, and still further improved regarding the compensation of predicted picture motion by changing a coding threshold level in response to picture motion and further by effecting more exact secondary prediction of picture motion. According to these improvements, an extremely high efficiency of transmission of precisely and correctly coded interframe picture signal can be attained.

Apparatus and method for differential sub-band coding of video signals

Abstract: A method and apparatus for achieving a high compression of a video signal. The PEL-by-PEL difference between an input signal consisting of digital PEL values of a scanned video signal and a motion compensated interframe prediction signal is decomposed into several narrow bands using separable two-dimensional quadrature mirror filtering (105). Each sub-band is quantized by a symmetric uniform quantizer (106-1-106-4) with a center dead zone. Entropy coders (124-1-124-4) code the quantized values by variable word-length coding the nonzero quantized values and transmitting that information with the corresponding run-length coded positional information. The outputs of the coders are combined by a multiplexer (108), the output of which is input to a buffer (123) which produces a constant rate bit stream. When the occupancy level of the buffer approaches maximum capacity, the dead zones and step sizes of the quantizers are adjusted to force more zero value quantized levels thereby reducing the amount of data being input to the buffer.

Video retrieval method and apparatus

Abstract: A method of characterizing a video includes the steps of extracting frame images from an input video, calculating a time length between each of the frame images and a next one of the frame images, assigning index information determined by the calculated time length to each of the frame images, stringing together the index information assigned to the frame images, and characterizing the input video by the strung-together index information. The index information is a character code, and the strung-together index information is a character code string. The frame images include head frame images located at scene changes of the input video. The input video is being broadcasted or is included in a data base.