Residual frame

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

Low-complexity and high-quality frame-skipping transcoder for continuous presence multipoint video conferencing

Abstract: This paper presents a new frame-skipping transcoding approach for video combiners in multipoint video conferencing. Transcoding is regarded as a process of converting a previously compressed video bitstream into a lower bitrate bitstream. A high transcoding ratio may result in an unacceptable picture quality when the incoming video bitstream is transcoded with the full frame rate. Frame skipping is often used as an efficient scheme to allocate more bits to representative frames, so that an acceptable quality for each frame can be maintained. However, the skipped frame must be decompressed completely, and should act as the reference frame to the nonskipped frame for reconstruction. The newly quantized DCT coefficients of prediction error need to be recomputed for the nonskipped frame with reference to the previous nonskipped frame; this can create an undesirable complexity in the real time application as well as introduce re-encoding error. A new frame-skipping transcoding architecture for improved picture quality and reduced complexity is proposed. The proposed architecture is mainly performed on the discrete cosine transform (DCT) domain to achieve a low complexity transcoder. It is observed that the re-encoding error is avoided at the frame-skipping transcoder when the strategy of direct summation of DCT coefficients is employed. By using the proposed frame-skipping transcoder and dynamically allocating more frames to the active participants in video combining, we are able to make more uniform peak signal-to-noise ratio (PSNR) performance of the subsequences and the video qualities of the active subsequences can be improved significantly.

Method for the detection and recovery of errors in the frame overhead of digital video decoding systems

Abstract: The disclosed invention is a method to detect candidate errors within the picture start code, picture header, and picture timestamp Upon detection, these errors may be confirmed and the impacts mitigated An error within the timestamp bit field is adaptively detected by the use of a threshold comparison, and a mechanism for concealing the timestamp information leaves only a small timestamp anomaly An error within the picture start code (PSC) is determined by adaptively analyzing the number of bits and the macro-block location of the next slice or GOB If a PSC is suspected to have been overrun due to an error, this method allows for data beyond the first GOB or slice to be recovered in the frame Depending on the extent of use of slices and GOBs, the method can recover a majority of the frame that otherwise would have been completely lost A candidate error within the picture header is evaluated by utilizing the first slice or GOB of the frame and analyzing information from a previous frame to check whether the current frame's header information should be replaced with the previous frame's header information Replacing the erred frame header can result in a majority of the data within the frame being recovered that would otherwise be discarded if the header was not replaced

Implicit frame-based processing for block-diagram simulation

Abstract: A run-time, frame-based processing mechanism executes a block diagram model by propagating frame attributes information from blocks on which a user specified the frame attributes information to all other blocks in the block diagram model. The frame attributes information includes an indicator that specifies whether or not the data flowing from one block to another is sample-based or frame-based, as well as the size of the frame in terms of number of samples and number of channels.

High frame rate ultrasound system

Abstract: A technique for increasing the display frame rate of a medical ultrasound imaging system. The system receives trigger signals, each based upon the occurrence of a predetermined event in a subject's cardiac cycle, such as an R-wave. In one technique, in response to each trigger signal, the ultrasound system acquires a series of frames, each frame comprising data representing an image of a portion of the subject's body at an associated acquisition time. A frame time is determined for each frame, each frame time being the time from the preceding trigger signal to the acquisition time for the frame. Two or more frame series are then played back in order of increasing frame times, thereby producing a display frame rate higher than the acquisition frame rate.

Frame interpolator, frame interpolation method and motion reliability evaluator

Abstract: A frame interpolator comprises a motion estimating unit dividing a current frame into a plurality of reference blocks, each reference block having a predetermined size, comparing the reference block with a predetermined search area set in a previous frame, and estimating an initial motion vector. A reliability evaluating unit evaluates reliability of the initial motion vector and generates reliability evaluation data regarding the evaluation result. A frame interpolating unit interpolates an intermediate frame to be inserted between the current frame and the previous frame on the basis of the initial motion vector and the reliability evaluation data A frame interpolator, a frame interpolation method, and a motion reliability evaluator, which are capable of improving interpolation quality of frames and reducing a block artifact, are provided.