Showing papers on "Residual frame published in 1998"

Method and apparatus for a copy-once watermark for video recording

Abstract: Method and apparatus for 'copy-once' of a digital video signal uses a watermark in the video signal. The embedded watermark has two versions: one indicates copy-never and a second indicates copy-once, the difference being a single watermark bit. The watermark carries additional bits representing a digitized attribute (image characteristic) of a particular video frame of the video signal, for instance an average value of the amplitude of a video field. The frame whose attribute is carried in the watermark has a field (or frame) marker, which is a special signal located in the overscan portion of the frame. A compliant video recorder verifies the watermark and the copy-once bit (48, 54), extracts the associated attribute from the watermark (56), and compares (68) it to the measured attribute (58) of the marked video frame. Only if the extracted attribute value and the measured attribute value match, is recording enabled. During the recording process (70), the frame markers are stripped (72), preventing second generation copies of the recorded video signal, and the copy-once bit is set to copy-never.

Method for tracking a video object in a time-ordered sequence of image frames

Abstract: A method for tracking a video object in a time-ordered sequence of image frames, comprises the steps of (a) identifying the object to be tracked in a first frame and determining its shape in the first frame; (b) selecting another frame, referred to as the last frame and identifying the shape of the object in the last frame; (c) selecting a number of intermediate frames between the first and last frames; (d) automatically identifying the shape of the object in the intermediate frames; and (e) interpolating between all of the frames in the sequence so as to determine the trajectory of the object in all of the frames

Apparatus and method for object based rate control in a coding system

Abstract: A method and apparatus for selecting a quantizer scale for each object within a frame to optimize the coding rate are disclosed. A quantizer scale is selected for each region or "object" within each frame such that the target bit rate for the frame is achieved while maintaining a uniform visual quality over the entire frame.

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.

Unidirectional streaming services in wireless systems

Abstract: A high layer protocol organizes Unidirectional Streaming Services (USS) data into frames and said data is transmitted to the wireless user's terminal. The USS data is not delivered until a criteria is satisfied, e.g., the receive buffer is filled to an appropriate value. After the USS data is received, the receiver verifies the received frames. If an error is detected a message is sent from the wireless terminal to the server (providing the unidirectional streaming service) requesting retransmission of the corrupted frame. This is a form of ARQ protocol. If the retransmitted frame arrives prior to the time that frame needs to be delivered, the corrupted frame is replaced by the retransmitted frame. Otherwise, if the retransmitted frame is not received prior to the time that frame needs to be delivered, the corrupted frame is reconstructed. Any retransmitted frame which arrives too late is discarded. An additional benefit of the present invention is that since the frames are buffered prior to delivery, interpolation, as opposed to extrapolation, can be used to improve the reconstruction quality of the corrupted frame. This optional feature of the invention uses both the preceding and succeeding frames, which are available in the buffer, to provide a better estimate of the corrupted frame.

Data sequence generator, transmitter, information data decoder, receiver, transceiver, data sequence generating method, information data decoding method, and recording medium

Abstract: The probability of frame destruction is lowered while suppressing the redundancy of the transmission data. On the transmitting side, a predetermined unique word is contained in a frame n for storing the n-th data, and header information n, frame length information and header information n-1 of the frame n-1 one frame before the frame n are subjected to error-correcting coding, contained in the frame n, and transmitted. On the receiving side, the header of the frame n is received. When the frame length information is transmitted without error, the timing of frame synchronization is specified by the frame length information, while when the frame length information is transmitted with error, the timing is specified by detecting the unique word and header information in the next frame n+1. When the header of the frame n is not successfully decoded, the information data of the frame n is decoded by using the header information n inserted into a predetermined position of the frame n+1.

A frame format and frame assembling/disassembling method for the frame format

Abstract: A frame format for a communication signal containing a bit stream including ATM formatted data, the bit stream being organized into frames (200) according to the frame format. The frame format includes a frame header (230), a data payload (240) having a first variable size, and a block code (250) having a second variable size which is used for error correction. The data payload (240) includes at least a partial ATM data cell (242) or a complete ATM data cell (244).

Method and apparatus for playing an MPEG data file backward

Abstract: The present invention has been made in consideration of linear reverse playback of MPEG video data and has particular applications to video special effect editing. According to one aspect of the present invention, the disclosed system uses a minimum number of frame storage to buffer decompressed I and P frames so as to decompress B frames in a reverse order and subsequently display the B frames. Every time, it comes to display the decompressed I and P frames buffered in the frame storage, an I frame or a P frame in a group of picture (GOP) prior to current GOP is decompressed and buffered into one of the frame storage that becomes available when the content therein has been retrieved for display. The cyclic use of the frame storage and the time that would be otherwise spent for decompressing B frames guarantees a linear reverse playback of MPEG video data without showing retardant visual effects that often result from non-even decoding processes in displaying compressed frames.

Multiple display synchronization apparatus and method

Abstract: A method of synchronizing, at a system frame display rate, a first set of frames displayed by a first monitor with a second set of frames by a second monitor, utilizes frame production rates of the two sets of frames to set the system frame display rate. More particularly, the first set of frames are produced at a first frame production rate by a first graphics engine, and the second set of frames are produced at a second frame production rate by a second graphics engine. The first frame production rate and second frame production rate first are compared to determine which frame production rate is slower. The system frame display rate then is set to be no greater than the slower of the two frame production rates.

Adaptive encoding of a sequence of still frames or partially still frames within motion video

Abstract: Method, system and computer program product are provided for adaptively encoding in hardware, software or a combination thereof a series of still or partially still pictures using motion video encoding. A pre-encode statistics measurement unit is employed to derive statistics on each frame of the sequence of video frames to be encoded. The statistics are determinative of whether the frame comprises a still frame. If so, at least one controllable parameter to be used to encode the still frame is modified, and an encoding engine employs the at least one controllable parameter to encode the still frame so that pulsation artifacts are prevented between still frames of the series of still frames. Partial still picture encoding to prevent pulsation artifacts on a macroblock level is also addressed.

Dark frame subtraction

Abstract: A method of adjusting a portion of a dark frame in accordance with compensation values related to dark reference pixels of a picture frame to obtain an adjusted dark frame portion, and then subtracting the adjusted dark frame portion from a corresponding picture frame portion. The technique may be used to improve the accuracy of image sensors such as those used in digital cameras or video conferencing cameras by compensating for dark current noise. The technique may be applied to both CMOS image sensors and, in general, to any image sensors requiring dark frame subtraction. The techniques may also be used in conjunction with calibration of image sensors and imaging systems.

Device and method for converting frame rate

Abstract: Device and method for converting a frame rate, is disclosed, in which a motion compensated frame is newly produced in converting a frame rate, particularly, in a digital TV of a PAL or NTSC system, a motion component compensated separate frame is provided between frames and displayed to horizontal/vertical synchronizing signals two times faster than an original frequency for eliminating flicker, and in a case when a video signal of a film rate is converted into a video signal of a frame rate of PAL or NTSC system, motion component compensated new frames are produced for converting the frame rate for preventing blurring occurred in motion portions. And, by differently compensating motion components of N frames inserted between two frames and processing the frames in real time, a slow motion can be displayed smoothly without any separate memory.

Increased video playback framerate in low bit-rate video applications

Abstract: A method comprising selecting a number of blocks of a frame pair and synthesizing an interpolated frame based on those selected blocks of the frame pair. Additionally, the synthesis of the interpolated frame is aborted upon determining the interpolated frame has an unacceptable quality.

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.

Encoding digital signals

Abstract: A motion factor coding apparatus receives an input video signal which is applied to a subtractor and to a motion estimator which generates motion vectors for the current frame relative to a reference frame that is stored in the motion estimator. The motion vectors are passed to a buffer which are then iteratively update in a re-estimator. The number of iterations can be set to a fixed number or can be controlled by measuring the effect of each successive update on the motion. When a satisfactory number of iterations is reached, update motion vectors are passed to a motion compensator which generates a predicted frame which is applied as another input to the subtractor where the predicted frame is subtracted from the current frame in the input digital video signal. The subtraction removes temporal redundancy in the signal.

Process and apparatus for converting an mpeg-2 bitstream into an smpte-259 compatible bitstream

Abstract: A process and apparatus for converting an MPEG-2 bistream into an SMPTE-259 compatible bitstream are characterized by a frame rate converter which is selectively enabled to drop every 1001st frame of the incoming MPEG-2 bitstream depending on the input bitstream frame rate. If the input bitstream frame rate is other than 29.97 or 59.94 Hz, a frame dropper is enabled to discard every 1001st frame. The present converter can convert many different types of input bitstreams, such as all I types, IPIP types, or complex GOP types containing I, P, and B frames. The enabled frame dropper will drop either the I or P frame if it occurs as the 1001st frame, but if the 1001st frame is of the B frame type, the pixel information of the B frame is dropped. This produces a minimum in loss of information during the conversion. The format converter allows existing SMPTE-259 routing equipment to route and utilize MPEG-2 bitstreams, such as HDTV applications.

Real-time variable bit rate encoding of video sequence employing statistics

Abstract: Method, system and computer program product are provided for adaptively encoding in hardware, software or a combination thereof a sequence of video frames in real-time. Pre-encode perceptual activity measurement processing is employed to derive statistics on each frame of the sequence of video frames to be encoded. The statistics are used by variable bit rate logic to obtain a number of bits to be used in encoding each frame. The number of bits to be used is provided to a single encoding engine, which encodes the sequence of video frames and produces a constant quality, variable bit rate bitstream output. The pre-encode processing employs a regulator as the global data flow control and synchronization for the encoder. Perceptual activity analysis on each frame of the sequence of video frames can derive information on, for example, shading, scene change, fade, color, motion and/or edge presence within the frame. Voting gives greater weight to the presence of certain characteristics within the frame.

Apparatus and method for macroblock based rate control in a coding system

Abstract: A method and apparatus for selecting a quantizer scale for each macroblock within a frame to optimize the coding rate is presented (130). A quantizer scale is selected for each macroblock (120) within each frame such that the target bit rate for the frame is achieved while maintaining a uniform visual quality over the entire frame.

Motion image coding apparatus adaptively controlling reference frame interval

Abstract: A motion image coding apparatus providing enhanced image quality as compared with the prior art includes a coding unit for coding first, second and third frames, a prediction efficiency calculating circuit for calculating prediction efficiency in inter-frame prediction, in coding by the coding unit using said first or second frame as a reference frame, and a reference frame interval determining circuit for determining a reference frame interval which is a time interval between the first and second frames, time interval between the second frames and time interval between the first frames.

Region based moving image editing system and method

Abstract: One embodiment uses a computer system to define areas with moving image information of interest in a sequence of digital moving image frames. The sequence of digital moving image frames has at least three frames, a first frame, a second frame and a third frame, in time sequence. A set of points identifies the areas with moving image information of interest on the first frame. In the third frame, the areas with moving image information of interest are identified with the set of points. Each point in the set of points has an explicitly defined location in the first frame and an explicitly defined location in the third frame. The location of each point in the first frame corresponds to the same areas with moving image information of interest as each point's location in the second and third frames. For example if one of the points is located at the tip of a runner's left toe in the first frame, then that point will be located at the tip of the runner's left toe in both the second and third frames. The computer system automatically computes the location of the areas of interest in the second frame.

Method of frame-by-frame calculation of quantization matrices

Abstract: A method of reducing distortion in a video signal by coding a video frame utilizing a quantization matrix specifically determined for the video frame. The method includes the steps of determining the degree to which the video signal is spread about an average value, determining an average quantizer scale-value Q for the video frame, determining a reference weighted distortion for all DCT frequency bands in the video frame, determining the quantization parameter through a normalized distortion function, determining each weight for each DCT frequency band and coding the video frame taking into account the determined weights in the quantization matrix.

Deinterlacing a video signal using a motion detector

Abstract: Deinterlacing a video signal using a motion detector is disclosed. In one embodiment, a divider, a comparator, and an interpolator deinterlace a video signal and reduce combing artifacts. The divider forms a ratio of inter-field activity to intra-field activity in a video frame. The ratio is compared to an empirically determined threshold. If the ratio is greater than the threshold, then there is motion in the frame and the second field is interpolated from the first field. If the ratio is less than the threshold, then there is no motion in the frame and no change is made to the frame.

System for collecting ultrasound imaging data at an adjustable collection image frame rate

Abstract: Ultrasound imaging data is collected at an adjustable collection image frame rate. Echoes produced from transmission of ultrasound energy into a subject's body are processed by an image frame acquisition device to produce a series of image frames. Each image frame comprises data representing an image of a portion of the subject's body at a given time. The image frames include collection image frames and interrogation image frames. The interrogation image frames are for sampling the subject's body between collection of at least some collection image frames. The difference between the current image frame and at least one preceding image frame is determined and a frame correlation coefficient is output based upon the difference. The collection image frame rate of the image frame acquisition device is adjusted in inverse proportion to the most recent frame correlation coefficient.

Method and device for noise reduction

Abstract: A method of reducing noise in a video signal which includes a plurality of video frames being composed of a plurality of pixels, the method comprising the steps of: comparing video information contained in a current video frame and a plurality of temporally adjacent video frames; selecting from the current video frame and the adjacent video frames the video information that according to a predetermined condition is likely to be correct for the current video frame; and finally assigning the selected video information to the current video frame to thereby produce a video frame wherein noise has been reduced.

Fast frame optimization in an audio encoder

Abstract: In a transform encoder for audio data, encoded data in the form of mantissas, exponents and coupling data is packed into fixed length frames in an output bitstream. The fields within the frame for carrying the different forms of data are variable in length, and apace within the frame must be allocated between them to fit all of the required information into the frame. The space required by the various data types depends on certain encoding parameters, which are calculated for a particular frame before the data is encoded, thus ensuring that the encoded data will fit into the frame before the computationally expensive encoding process is carried out. Information in relation to, for example, transform length, coupling parameters and exponent strategy are determined, which allows the space required for the coupling and exponent data to be calculated. The mantissa encoding parameters can then be iteratively determined so that the encoded mantissas will fit into the frame with the other encoded data. The determined encoding parameters are stored and the audio data is encoded according to those parameters after it has been determined that the encoded data will fit into the frame.

Video display method and apparatus with synchronized video playback and weighted frame creation

Abstract: A video display apparatus and method for displaying decoded video frames from an encoded video stream utilizes a display time difference determinator that detects a frame display time difference, on a per frame basis if desired, between a refresh rate based frame display time, and a video playback frame rate display time to generate frame display time difference data. This is done on a continuous basis to detect synchronization problems between video data that is to be displayed simultaneously with non-video data on a display device such as a progressive display screen. A pixel blender blends pixel data from an adjacent frame, such as an already reconstructed previous frame or next frame, to create a temporally adjusted frame based on the determined frame display time difference data.

Delay balanced video encoder system

Abstract: A process and apparatus for encoding are provided, wherein fields of a digital signal are processed to detect repeat fields. Adjacent pairs of the non-repeated fields are organized into frames. A determination is made whether to encode each of the frames as an intraframe, a predicted frame or a bidirectionally predicted frame. The frames are encoded in a specific, predefined order relative to the order of capture of the frames and the type of frame. After each bidirectionally predicted frame that immediately precedes one of the detected repeat fields, encoding of a frame is delayed for one field time. Encoding is paused after encoding each reference frame that is the very next reference frame to be encoded after a second reference frame, which second reference frame immediately precedes one of the detected repeat fields. A process and apparatus for statistically multiplexing multiple encoded digital video signals are also provided. Statistics are gathered for one or more of the encoded digital video signals and bit rates are allocated for transmitting one or more of the digital video signals as encoded. One of the digital video signals is encoded to produce a certain number of bits for each encoded picture in accordance with a decoder buffer model having a predefined size and filling at a certain bit rate, which is updated with the bit rate allocated to the one digital video signal. The update is delayed by a number of field display times depending on the number of times encoding pauses, and a presumed number of times decoding pauses, as a result of the detected repeat fields.

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.

Coding an intra-frame upon detecting a scene change in a video sequence

Abstract: A method and apparatus is described for encoding a video sequence of frames. Each frame in the video sequence is organized in blocks of pixels. A scene change is detected when a current frame in the video sequence is substantially different from a previous frame. When it is determined that the current frame is the change in scene, the current frame is coded to be an intra frame with each block of pixels of the intra frame is being an intra-coded block. Coding the sequence of frames produces a compressed bit stream having a coded intra frame at each scene change. Each coded intra frame provides an access point in the bit stream from which a storyboard of the scenes in the video sequence can be generated.

Repeat field detection using checkerboard pattern

Abstract: The present invention is directed to a method for encoding an uncompressed digital video bit stream. The video bit stream comprises successive frames, each of which includes one or more odd fields and one or more even fields. Such frames with more than two fields may result from a telecine process as discussed above. The inventive method comprises the steps of capturing successive frames of said video bit stream in an encoder system, determining statistics for each frame to make an encoding decision for the frame, the statistics for each frame being determined in a single field time, using a statistically valid subset of pixels from the frame, and encoding the frame in said encoding system in a manner responsive to said encoding decision to generate an encoded bit stream. In a preferred embodiment of the invention, the statistically valid subset of pixels has a checkerboard pattern. Illustratively, the encoding decision involves dropping a repeated field in a frame and inserting a repeat field flag into the encoded bit stream.