Abstract: A look-ahead system and method for pan and zoom detection in video sequences is disclosed. The system and method use motion vectors in a reference coordinate system to identify pans and zooms in video sequences. The identification of pans and zooms enables parameter switching for improved encoding in various video standards (e.g., H.264) and improved video retrieval of documentary movies and other video sequences in video databases or other storage devices.

Abstract: A look-ahead system and method for pan and zoom detection in video sequences is disclosed. The system and method use motion vectors in a reference coordinate system to identify pans and zooms in video sequences. The identification of pans and zooms enables parameter switching for improved encoding in various video standards (e.g., H.264) and improved video retrieval of documentary movies and other video sequences in video databases or other storage devices.

Abstract: A look-ahead system and method for pan and zoom detection in video sequences is disclosed. The system and method use motion vectors in a reference coordinate system to identify pans and zooms in video sequences. The identification of pans and zooms enables parameter switching for improved encoding in various video standards (e.g., H.264) and improved video retrieval of documentary movies and other video sequences in video databases or other storage devices.

Abstract: A method, apparatus, system, and signal-bearing medium that in an embodiment detect that a first packet is not received, add a place holder for the first packet in a buffer, request retransmission of the first packet, and create an estimated packet based on a combination of a second packet previous to the first packet, a third packet following the first packet, and a fourth packet from a previous frame that is spatially corresponding to the first packet. In another embodiment, a method, apparatus, system, and signal-bearing medium are provided that send a encoded packet to a receiver, save the encoded packet in a bitstream, determine whether the encoded packet is lost, and when the encoded packet is lost, decode the bitstream with the lost packet omitted and insert a reconstructed frame associated with the lost packet into a reference frame storage. In another embodiment, when the encoded packet is lost, a decoder is run on a reference frame chosen as the last uncorrupted frame.

Abstract: A look-ahead system and method for pan and zoom detection in video sequences is disclosed. The system and method use motion vectors in a reference coordinate system to identify pans and zooms in video sequences. The identification of pans and zooms enables parameter switching for improved encoding in various video standards (e.g., H.264) and improved video retrieval of documentary movies and other video sequences in video databases or other storage devices.

Abstract: A look-ahead system and method for pan and zoom detection in video sequences is disclosed. The system and method use motion vectors in a reference coordinate system to identify pans and zooms in video sequences. The identification of pans and zooms enables parameter switching for improved encoding in various video standards (e.g., H.264) and improved video retrieval of documentary movies and other video sequences in video databases or other storage devices.

Abstract: A method and apparatus for reducing the output bit rate in a video object planes sequence encoder. An approximation of the shape of an object on a current frame is generated and used, along with a predicted image of the object from a subsequent frame and an estimate of the displacement of the object, to predict an image of the object in a current frame. A stripe is formed around the predicted image and the picture elements contained in the stripe are assigned texture values. The predicted image and stripe are subtracted from the current frame to form an error signal which is masked by the approximate shape of the object and provided to an entropy coder for transmission at an output bit rate.

Abstract: Video composition techniques are disclosed for processing video information from a plurality of sources to provide a video image having a plurality of rectangular regions. Each rectangular region displays video information from a specific one of the plurality of video sources. The video information from each video source is in the form of an incoming digital bit stream. The digital bit stream from a first video source has a first bit rate, and the digital bit stream from a second video source has a second bit rate where the first bit rate may or may not be equal to the second bit rate. The incoming digital bit streams are fed to a rate matching circuit which converts all incoming digital bit streams to a common bit rate. The output of the rate matching circuit is fed to a synchronization arid multiplexer circuit which places video information from specific digital bit streams into corresponding rectangular regions of a composite video image.

Abstract: Improved bit rate reduction techniques are disclosed. When incorporated into an existing video processing system having a DCT coefficients processor, the motion vector processor disclosed herein provides enhanced computational and memory storage efficiencies over prior art designs. The motion vector processor includes a microprocessor and associated motion vector memory. The motion vector memory is adapted to store a plurality of motion vectors corresponding to at least one image frame containing a plurality of macro blocks. Each motion vector is represented by an X value and a Y value, the X value and the Y value signifying image changes within a given macro block from a given frame to the immediately preceding frame.

Abstract: Efficient digital compression of 3D/stereoscopic video is achieved by a novel technique in which various views forming 3D/stereoscopic video are coded by utilizing the redundancies among the views. Coding is performed in a manner compatible with existing equipment to allowing decoding of one layer of video for display on normal (i.e., monoscopic) displays. The motion compensated discrete cosine transform ("DCT") coding framework of existing standards such as the Motion Pictures Expert Group-Phase 2 ("MPEG-2") video standard is exploited, and when necessary extended, to result in highly efficient, yet practical, coding schemes.

Abstract: Efficient digital compression of 3D/stereoscopic video is achieved by a novel technique in which various views forming 3D/stereoscopic video are coded by utilizing the redundancies among the views. Coding is performed in a manner compatible with existing equipment to allowing decoding of one layer of video for display on normal (i.e., monoscopic) displays. The motion compensated discrete cosine transform ("DCT") coding framework of existing standards such as the Motion Pictures Expert Group-Phase 2 ("MPEG-2") video standard is exploited, and when necessary extended, to result in highly efficient, yet practical, coding schemes.

Abstract: An encoder segments frames in a sequence of digital images into multiple regions of arbitrary shape each of which has a corresponding motion vector relative to a previous decoded frame. A hierarchical multi-resolution motion estimation and segmentation technique, which segments the frame into multiple blocks and which assigns a best motion vector to each block is used. Blocks having the same or similar motion vector are then merged to form the arbitrarily-shaped regions. The shape of each region is coded, and a decision is made to code additional image data of each region in one of three modes. In a first inter-frame mode, a motion vector associated with a region is encoded. In a second inter-frame mode, a prediction error for the region is also encoded. In an intra-frame mode, the intensity of each picture element in the region is encoded.

Abstract: A novel method and apparatus is disclosed for controlling inverse discrete cosine transform ("IDCT") mismatch between an encoder and decoder using different IDCT implementations under all coding conditions. Sychronization between the encoder and decoder is forced by selectively setting certain small DCT coefficients, which are prone to mismatch, to zero at the encoder. Advantageously, the invention may be implemented solely in the encoder to minimize system complexity and cost, and allow for IDCT mismatch control utilizing conventional decoders.

Abstract: Encoder/decoder buffer overflow and underflow encountered when employing actually variable or effectively variable bit-rate channels for communicating encoded video images and corresponding audio signals are overcome by adjusting the parameters of a video encoder in response to a representation of cell delay variation, i.e., jitter, determined at a remote decoder.

Abstract: Encoder/decoder buffer overflow and underflow encountered when employing actually variable or effectively variable bit-rate channels for communicating encoded video images and corresponding audio signals are overcome by adjusting the parameters of a video encoder in response to a representation of cell delay variation, i.e., jitter, determined at a remote decoder.

Abstract: A video conference system provides eye contact and a sense of presence to a plurality of conference participants located in respective remotely-sited conference rooms. Each conference room contains at least one video telephone or communications device that includes a video camera for generating video signals indicative of a sequence of local conferee image frames, and an image receiver for displaying image frames of at least one remote conferee. The image receiver, the video camera, and the eyes of the local conferee define a parallax angle. The video conference system further includes a frame generating system, responsive to the video signals, for analyzing local conferee image frames and generating a corresponding sequence of parallax-compensated frames. A signal indicative of each respective sequence of parallax-compensated frames is transmitted to a corresponding image receiver, whereby apparent eye contact is provided between each local conferee and a displayed image of a corresponding remote conferee.

Abstract: A Transform Coder Unit (TCU) to transform an arbitrarily shaped image into optimal transform coefficients (OTC) for data transmission. The TCU comprises a forward transform which transforms the image to transform coefficients, and a TCS generator which generates a transform coefficient set (TCS) from the transform coefficients. The TCU also contains an inverse transform which transforms the TCS to a computed region block having computed pel values. Finally, the TCU comprises a replacer which replaces those computed pel values corresponding to the interior pel set with the original pel values to form a modified computed region block which is re-iterated until optimal transform coefficients are determined. The present invention is also directed at a process for determining optimal transform coefficients using the aforementioned device.

Abstract: Complications of timing recovery in an ATM receiver are overcome by employing a first phase lock loop including a phase comparator, filter, voltage controlled oscillator (VCO) and output counter to lock to systems clock reference (SCR) values which are asynchronously received from a remote ATM transmitter. The SCR values represent the instantaneous values of a system timing clock (STC) at the instant of transmission of the asynchronous SCR values. In the receiver, the output counter is first set to the value of the initial received SCR value so that the derived STC is available for decoding data cells in the initial received packets. Then, so-called Presentation/Decode Time Stamps (PTS/DTS) included in the audio and video data are advantageously employed in conjunction with STC to display properly the received data. Invention, underflow of the receiver data buffers is alleviated by the addition of a "jitter-delay (D.sub.

Abstract: A quantization parameter for use in encoding a region of an image is developed from a) a categorization of the region into one of a predetermined plurality of perceptual noise sensitivity (PNS) classes, b) a level of psycho-visual quality that can be achieved for the encoded version of the image, the level being selected from among a plurality of predetermined levels, and c) a prestored empirically derived model of the relationship between the PNS classes, the psycho-visual quality levels and the values of the quantization parameter. PNS indicates the amount of noise that would be tolerable to a viewer of the region, i.e., the perceptual sensitivity of the region to noise. Some characteristics on which PNS classes may be based are: spatial activity, speed of motion, brightness of the region, importance of the region in a particular context, the presence of edges within the region and the texture of the region, e.g., from "flat" to "highly textured".

Abstract: The problems of buffer overflow and underflow encountered when employing actually variable or effectively variable bit-rate channels for communicating encoded video images are overcome by jointly controlling the number of bits employed to encode each video frame and the transmission bit-rate of the variable bit-rate channel as experience by the encoder. The selection of the number of bits employed to encode each video frame, and hence the encoder bit-rate, as well as the associated channel bit-rate are determined from the encoder buffer fullness, a determination of the decoder buffer fullness and any constraint imposed on the channel. The encoder is responsive to the selected encoder bit-rate and accordingly adjusts its encoding parameters so as to achieve the selected encoder bit-rate.