Residual frame

About: Residual frame is a research topic. Over the lifetime, 4443 publications have been published within this topic receiving 68784 citations.

Video coding method and apparatus using multi-layer based weighted prediction

Abstract: A method and apparatus for efficiently encoding a plurality of layers using inter-layer information in a multi-layer based video codec are disclosed. The video encoding method includes operations of reading the weighting factors of one layer; performing motion compensation on reference frames for the current frame based on a motion vector; generating a predicted frame for the current frame by acquiring a weighted sum of the motion-compensated reference frames using the read weighting factors; and encoding the difference between the current frame and the predicted frame.

Method and apparatus for detecting text associated with video

Abstract: A method and apparatus for detecting text associated with video are provided. The method of detecting the text of the video includes reading a t-th frame (where t is a positive integer) among frames forming the video as a current frame, determining whether there is a text area detected from a previous frame which is a (t−N)-th (where N is a positive integer) frame among the frames forming the video, in the current frame, and upon determining that there is no text area detected from the previous frame in the current frame, detecting the text area in the entire current frame. Upon determining that there is the text area detected from the previous frame in the current frame, the text area is detected from a remaining area obtained by excluding from the current frame an area corresponding to the text area detected from the previous frame. Whether there is a text area in a next frame which is a (t+N)-th frame among the frames forming the video is verified.

Video transcoding method and apparatus

Abstract: Provided are a method and apparatus for selecting an appropriate reference frame at high speed from a plurality of reference frames when transcoding an input video stream into a different format having a different group of pictures (GOP) structure from that of the input video stream. A transcoder, which transcodes an input video stream into an output video stream, includes a reconstruction unit which reconstructs transform coefficients and a video frame from the input video stream; a selection unit which selects one of a first frame, which is referred to by the video frame, and a second frame, which is located at a different position from the first frame, based on sizes of the transform coefficients; and an encoding unit which encodes the reconstructed video frame by referring to the selected frame.

Error resilient video coding using flexible reference frames

Abstract: Conventional video coding techniques make use of the most recently decoded reference frame(s) for motioncompensated inter prediction. However, it has been shown that to allow using reference frames in a flexible way such that not only the latest reference frames are used is beneficial. A typical use of flexible reference frame is feedback based reference picture selection, wherein error-free reference frames available in both the encoder and decoder sides are selected and used for inter prediction reference. This paper first overviews support of reference picture selection in different video coding standards, and then presents three specific feedback based reference picture selection methods using flexible reference frames. In addition, a novel simple reference frame management method that enables using of flexible reference frame is proposed. The reference frame management method enables much simpler video codec implementations compared to the complex reference frame management methods in H.263 Annex U and H.264/AVC. The proposed coding methods and some conventional methods are compared with each other. Simulation results show significantly improved error resiliency performance of the proposed reference picture selection methods compared to conventional methods. The effect on the performance imposed by feedback delay variation is also shown. Thanks to the merits, support of flexible reference frame and the reference frame management has been adopted to the AVS-M video coding standard.

Video signal coding systems and processes using adaptive quantization

Abstract: A compression system and process employs a group of quantizers (or set of predefined quantized values) and involves the selection of the quantizers for each video frame or frame portion. For each frame portion, a selection of the most appropriate quantizer is made. The selection of which quantizer from the selection group is most appropriate for coding of a video frame or frame portion is based on a formula which takes account both the distortion (accuracy) and bit rate characteristics of each quantizer. The quantizer that exhibits the best combined distortion and bit rate characteristics is selected for coding the frame or frame portion. A similar formula, based on both distortion and bit rate characteristics, is used to select the particular quantization value within the quantizer set for each video signal value being coded.