Residual frame

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

Method and apparatus for decoding variable rate data using hypothesis testing to determine data rate

Abstract: A system and method for determining the data rate of a frame of data at a receiver of a variable rate communications system. A vocoder at a transmitter encodes a frame of data at one of the rates of a predetermined set of rates. The data rate is dependent on the speech activity during the time frame of the data. The data frame is also formatted with overhead bits, including bits for error detection and detection. At the receiver, the data rate for the frame is determined based on hypothesis testing. Because the data rate is based on speech activity, a hypothesis test may be designed based on the statistics of speech activity. The received data frame is first decoded into information bits at the most probable rate as provided by the hypothesis test. Error metrics are generated for the decoded information bits. If the error metrics indicate that the information bits are of good quality, then the information bits are presented to a vocoder at the receiver to be processed for interface with the user. If the error metrics indicate that the information bits have not been properly decoded, then the received data frame is decoded at the other rates of the set of rates until the actual data rate is determined.

An error concealment algorithm for streaming video

Abstract: A known problem in video streaming is that loss of a packet usually results into loss of a whole video frame. In this paper we propose an error concealment algorithm specifically designed to handle this sort of losses. The technique exploits information in a few past frames (namely the motion vectors) in order to estimate the forward motion vectors of the last received frame. This information is used to project the last frame onto an estimate of the missing frame. The algorithm has been tested on MPEG-2 video, providing very satisfactory results, and outperforming by several dBs in PSNR the concealment technique based on repetition of the last received frame.

Method for encoding and decoding video signals

Abstract: A method for encoding video signals by inverse motion compensated temporal filtering where video frames of a base layer are used to encode video frames of an enhanced layer into predicted images. For each image block in an arbitrary frame in an enhanced layer frame sequence, an area including a block, which is present in a base layer frame temporally coincident with the arbitrary frame and is at the same position as the image block, is enlarged according to the ratio between screen sizes of the two layers. A reference block most highly correlated with the image block is searched for in the enlarged area in the temporally coincident base layer frame through motion estimation and is used to obtain pixel difference values and a motion vector of the image block for encoding the image block into a predicted image, thereby improving coding efficiency.

Methods and apparatus for motion estimation using causal templates

Abstract: A method of generating a motion vector associated with a current block of a current frame of a video sequence includes searching at least a section of a reference frame to identify previously reconstructed samples from the reference frame that best estimate motion associated with previously reconstructed samples from the current frame associated with the current block. The previously reconstructed samples may form sets of samples. Such sets may be in the form of respective templates. The method then includes computing a motion vector identifying the location of the set of previously reconstructed samples from the reference frame that best estimates the set of previously reconstructed samples from the current frame associated with the current block. It is to be appreciated such a motion estimation technique is performed in both a video encoder and video decoder so that motion vector data does not need to be transmitted from the encoder to the decoder.

Apparatus and method for dynamically controlling the frame rate of video streams

Abstract: An apparatus and method for dynamically varying the frame rate of an image sequence is disclosed. In one embodiment, the image sequence is encoded and stored at different frame rates (e.g., 30, 25, 20 fps and so on). Alternatively, only the motion information, e.g., motion vectors, for the other frame rates are stored.