Showing papers on "Residual frame published in 1991"

Layered DCT video coder for packet switched ATM networks

Abstract: A digital video encoder encodes a video frame into a differential video frame for transmission over a packet switched network. The video encoder includes an inter-frame encoder, an intra-frame encoder, and an encoding selector for selecting between the inter-frame and intra-frame encoder depending on the relative motion between the video frame being encoded and the previous video frame. A composite frame combiner provides a composite intra/inter-frame encoded difference frame having one set of pixels encoded by the inter-frame encoder, and another set of pixels encoded by the intra-frame encoder. The set of intra-frame encoded pixels includes at least one square or rectangular pixel block, a vertical strip of pixel blocks, and a horizontal strip of pixel blocks. Difference frames are encoded into separable data sets representing video information within a particular range of image resolution. A discrete cosine transform (DCT) is used to transform the difference pixels into corresponding DCT coefficients which are separable, by resolution, into the data sets providing coefficient layers. A packetizer formats the data sets into asynchronous transfer mode (ATM) packets for transmission over network.

Frame switching relay for asynchronous digital network

Abstract: A frame switching relay switches frames between input and output paths by multiplexing of the paths at frame cell level. A frame is divided into cells having a constant number of bits, whereas the frames are of variable length. The switching relay only retransmits frames that have been completely written in the buffer memory. A context memory preserves the address of the first cell at the start of the writing of a frame in the buffer memory, and memorizes the address of the output path for which the frame is destined, until the frame is completely written. A checking circuit checks that the writing of the frame does not cause an "overflow" in the buffer memory, by updating the number of cells awaiting reading and respectively associated with the output paths. If there is no overflow, the address of the first cell of the frame is written in one of the address queues as a function of the destination output path address. The frame is subsequently read by incrementation of the address of the first cell until the end of the frame is detected.

Video signal compression using 2-d adrc of successive non-stationary frames and stationary frame dropping

Abstract: An apparatus for highly efficient encoding of a digital image signal comprising frames of pixels converts the digital image signal into a blocked signal, sub-samples the blocked signal to reduce the number of pixels in each block by one-half and then performs adaptive dynamic range coding (ADRC) and frame dropping on the sub-sampled signal. The ADRC compresses the amount of pixel data in a first frame to half of a two-frame target value by subtracting the minimum value of the pixels in a block from each of pixels in the block, then representing each of the resultant pixel data values with a smaller number of bits than was originally used. This smaller number is determined based on the dynamic range of the block and the target value. A second frame following the first frame is dropped if it is detected as a stationary frame, or is compressed using ADRC to the two-frame target value reduced by the amount of data generated for the first frame if detected as a non-stationary frame.

Frame skip encoding apparatus for moving images

Abstract: In a moving image encoding apparatus, an image signal is converted into a digital image signal by an A/D converter and is stored in frame memory 110 In addition, a movement vector detector 300 detects a movement of the output of the frame memory 110 In an orthogonal transformer 130, a difference signal between a present frame image which is stored in the frame memory 110 and a previous frame image which is stored in a variable delay frame memory 210 is supplied, in which the difference signal is converted by orthogonal transformation The orthogonally transformed transformation signal is quantized into a linear or nonlinear discrete level on the basis of a step width of quantization from a step size controller 600 in a quantizer 140 Then, the quantized data is encoded into a variable length code in a variable length encoder 150 A movement vector detector 300 detects movement of the image by pattern matching processing between the present frame and the previous frame A movement vector/encoding mode judger 310 generates the movement vector 3 and the encoding mode 4 The variable length code is transmitted to the transmission circuit after adding a movement vector 3 and encoding mode 4 In these operations, a frame rate controller 700 controls the processing rate of each frame image in the entire apparatus Frame rate controller 700 calculates a total frame skip number S T which corresponds to the total number of frames that are not transmitted after a frame has been transmitted The total frame skip number S T is calculated by selecting a smaller sum of an externally set signal S min , signal S M which is calculated from the degree of movement compensation and S S which is calculated from the degree of quantization, and an externally set signal S max

Noise reduction in frame transmitted video signals

Abstract: A method for reducing noise in a reference frame of video information by determining the mean absolute difference, MAD o , between each block in the reference frame and identically located blocks in adjacent frames. If MAD o is A, a search is made for a block in the adjacent frame that matches the block in the reference frame. This is labelled MAD min . If MAD o for the block in the adjacent frame is

Fluoroscopic method with reduced x-ray dosage

Abstract: A method for fluoroscopically observing a living creature with reduced x-ray dosage is usable with a video monitor for displaying frames of image samples received during respective ones of frame scan intervals that regularly and successively occur at a display frame rate sufficiently high that brightness flicker is acceptably low to a human observer; an x-ray source that can be gated on for intervals not as long as a display frame; a fluoroscopic camera, including a raster-scanning video camera and a x-ray-to-light conversion apparatus with persistence not appreciably longer than a display frame; and frame filling apparatus for grabbing frames of image samples and interpolating between successively grabbed frames of image samples, when necessary, to generate frames of image samples at said display frame rate During ones of said successive frame scan intervals, x-ray radiation is directed from the gated x-ray source through the living creature; the x-ray shadow of at least a portion of the living creature is viewed with the fluoroscopic camera; and the frame filling apparatus grabs frames of image samples from the raster-scanning video camera to be stored in frame stores and used as bases from which to compute fill frames of image samples The frame filling apparatus continuously supplies to the video monitor the frames of image samples it generates at display frame rate

Camera zoom/pan estimation and compensation for video compression

Abstract: Most image coding algorithms, like the P X 64 and MPEG-1 standards, use locally derived estimates of object motion to form a prediction of the current frame. But camera motion, such as zooms and pans, which systemically affect the entire frame, is seldom handled efficiently. In this paper, we study the modeling, estimation and compensation of global motion caused by camera zooms and pans, we model the global motion in each frame with just two parameters: a scalar zoom factor and a 2D pan vector. Parameter estimation minimizes the squared prediction error of either the difference frame or the optical flow field. The estimated parameters are then used to construct a zoom/pan compensated prediction of the current frame, upon which some local motion compensation algorithm can then be applied to model object motion. Simulations suggest that these two global motion estimation algorithms are robust and accurate, and that global motion compensation provides a better prediction of the current frame with a potentially large reduction of motion side information.

Image signal high efficiency encoder and decoder

Abstract: PURPOSE:To improve processing efficiency by detecting intra-frame and odd and even inter-field moving vectors and the added difference of the absolute value of each picture element, selecting an efficient mode from movement compensation and respective block division modes, and controlling a frame memories with movement compensation device. CONSTITUTION:Frame/field movement detection circuits 22 and 21 detects the intra-frame and add and even inter-field moving vectors as well as the added difference of the absolute value of each picture element. A movement prediction mode discrimination circuit 23 and a selector 24 select the efficient mode from among the movement compensation modes in the unit of frame/field. A block division mode discrimination circuit 25 selects the efficient mode from among the respective block division modes for frame/field orthogonal transformation. An address generator 11 controls a frame memory group 10 based on the output of the circuit 25, and a frame memory group 20 with a movement compensation device operates based on the outputs of the circuits 23, 25. Thus, the field or frame processing efficiency can be improved.

Video scan rate conversion method and apparatus for achieving same

Abstract: In a video system, a video signal operates at a vertical scan rate to gente a first video frame characterized by a first number of lines per frame A method and apparatus are provided to convert the first video frame into a second video frame characterized by a second number of lines per frame The first video frame is stored at the vertical scan rate as digital samples A portion of the stored digital samples from each line of the first video frame are retrieved at the vertical scan rate The number of digital samples in the retrieved portion from each line of the first video frame is governed by a ratio equal to the second number divided by the first number, such that the retrieved portion from the first video frame is the second video frame

Arrangement for imaging a useful signal from the frame of a first digital signal at a first bite rate into the frame of a second digital signal at a second bite rate

Abstract: A circuit arrangement for imaging a useful digital signal from a frame of a first digital signal having a first bit rate into a frame of a second digital signal having a second bit rate, where the useful digital signal had been written into a first elastic memory and then read out of the first elastic memory in the frame of the first digital signal using a pulse stuffing technique, and with the frame of the first digital signal containing data representing the average fill level of the first elastic memory. The arrangement includes a second elastic memory, a frame detector for detecting the frame of the first signal and controlling activation of write-in of the useful digital signal from the frame of the first digital signal to the second elastic memory, and a frame generator which generates the frame of the second digital signal and controls activation of stuffing and of read-out of the useful digital signal from the second elastic memory into the frame of the second digital signal. An integrator determines the average fill level of the second elastic memory and a subtracter determines the difference between the average fill levels of the first and second elastic memories. This digital difference is fed to a digital control circuit, which includes a digital filter and a pulse density modulator that makes a stuffing decision as a function of the output of the digital filter. Each stuffing decision is input to the frame generator.

Apparatus and method for checking coincidence between frame specification data and an actual frame of an auto-printer

Abstract: In an auto-printer, wherein original frames to be printed are sequentially and automatically printed at an optimum exposure amount, which is determined based on frame specification data which includes exposure correction data, frame number and position data and stored during negative inspection. The frame position data is compared with an actual amount of film advancement detected when advancing the frame toward a print position, so as to determine whether the frame specification data corresponds to the actual frame placed in the print position. Simultaneously, the actual frame number of the frame placed in the print position is determined based on frame number bar code read from the photographic film during advancing the film, so as to compare the actual frame number with the frame number data. If it is determined by either one of the above described comparison that the frame specification data does not correspond to the actual frame, the auto-printer is automatically changed from an auto-print mode to a manual print mode.

Inter-frame adaptive prediction encoding system

Abstract: PURPOSE: To supply an inter-frame adaptive prediction encoding system which can prevent the deterioration of picture quality without deteriorating prediction efficiency even if movement changes and the correlation of inter-frame changes and which can reduce an operation amount required for prediction. CONSTITUTION: An encoding part 3 encodes a key frame at a prescribed interval as against a picture signal 1 which is continuously inputted, and a predictor 17 predicts an interpolation frame between the previously encoded key frames by using a preceding frame by two, the preceding frame and subsequent frame. COPYRIGHT: (C)1992,JPO&Japio

Traffic analysis including non-conforming behaviour via image processing

Abstract: In this paper an approach to traffic analysis is presented which employs image processing techniques to detect non-conforming behavior of vehicles on roadways in addition to providing the normal traffic statistics required for traffic monitoring. Traffic scenes recorded on video tape were used in the laboratory to test the approach. Binary images were obtained by subtracting each incoming sampled frame from a reference frame and thresholding the result. Centroids were calculated for each of the objects found in the binary images and were used to track the path of each vehicle on successive frames for its duration along the roadway in the region of interest. To minimize the computation time required to match objects from a given frame to the corresponding objects in the next frame, the velocity of each vehicle and inertial constraints on speed and angular deviation were used to predict each object's location in the next frame. The object nearest the target value was chosen as the appropriate match. The trajectory of each vehicle was checked for conformity. The implementation of the approach has been able to identify non-conforming vehicle behavior and issue a message on the monitor describing the detected behavior.

Recording and reproducing system for moving image data

Abstract: PURPOSE: To decode compressed moving image data as image data even when it is reproduced intermittently. CONSTITUTION: The compression encoding of core frame data in which only data in one moving image frame are compressed is performed by forming in fixed length setting a slice dividing one screen by the number from several to ten as a unit by a moving image compression encoder 1, and the data is recorded by re-arranging so that the slice of the core frame can be scattered on each frame by a codec 2 for ordinary reproduction. When fast reproduction is performed, recorded moving image data is read out at a frame interval in accordance with reproducing speed, and the core frame data can be reproduced by re-configuring in slice unit by a decoder 5 for fast reproduction. COPYRIGHT: (C)1993,JPO&Japio

Block-adaptive quantization of multiple-frame motion field

Abstract: Keywords: LTS1 Reference LTS-CONF-1991-022 Record created on 2006-06-14, modified on 2016-08-08

Speech decoding device

Abstract: PURPOSE:To improve the speech quality of a decoded speech by decoding information that is transmitted in a way that continuity is maintained between frames, while interpolating the information. CONSTITUTION:A 1st interpolator 10 is connected between a pitch information decoder 3 and a pulse train sound source 7 and a 2nd interpolator 11 is connected between a power information decoder 5 and a synthesizer 9. The 1st interpolator 10 continuously and smoothly vary intervals between pulses in a current frame outputted by the pitch information decoder 3 so that the continuity with the repetitive intervals of the pulse train in the current frame is maintained. The 2nd interpolator 11, on other hand, further divides the frame into small sections and varies the power in small-section units so that the continuity between the power in the current frame outputted by the power information decoder 5 and the power in the last frame is maintained.

Inter-frame motion predicting method

Abstract: PURPOSE:To improve the prediction accuracy of dynamic image data by executing a motion prediction of the other both direction prediction encoding frame, from one both direction prediction encoding frame and a forward prediction frame, etc. CONSTITUTION:A both direction prediction encoding frame B0 is predicted from an intra-encoding frame I0 and a forward prediction encoding frame P0 as heretofore, but a both direction prediction encoding frame B1 is predicted from the B0 and the P0 of one frame before. Also, the case when a both direction prediction frame B exists more than three frames (B0, B1, B2) between the frames I0 and P0 is also the same, and the frame B1, B2... except the frame B0 are always predicted from the B0, the B1... and the frame P0 of one frame before. In such a way, since the prediction from the both direction prediction encoding frame of one frame before can be executed, the prediction accuracy is raised, compared with the prediction from the frame I0 separated timewise, and the compression efficiency of image data is improved.

Noise reduction processing device for video signals by arbitration of pixel intensities

Abstract: The invention uses framestores for storing successive parts of three frames from the source of a video signal such as a camera, and a logical output selection unit arbitrates between the outputs for the frame to produce a reduced noise output to be fed to a T.V. monitor. If the noise of a pixel in the central frame is increased significantly compared to that in the first frame, the output of the third frame for that pixel is used to arbitrate between the two, for example, by selecting as the output that of the first frame if it is found that the output of the third frame is nearer to that of the first frame than to the second. Isolated noise specks are thereby reduced without the problems of motion smear.

Motion dependent video signal processing

Abstract: In, for example, a motion compensated video standards converter (Figure 1) wherein blocks in a first field or frame of a video signal are each compared with a plurality of blocks in the following field or frame of the video signal for deriving motion vectors representing the motion of the content of respective blocks between the first field or frame and the following field or frame, and wherein a correlation surface is generated for each block in the first field or frame, the correlation surface representing the difference between the content of the first block in the first field or frame and the content of each block in the following field or frame with which it has been compared; the minimum difference represented by the correlation surface and differing from the next smallest difference represented by the correlation surface by more than a predetermined threshold value is found to derive a motion vector, the number of motion vectors so derived is averaged (62) over a predetermined number of fields or frames, and the threshold value is varied (67, 68, 69) in dependence on the average.

Moving target detection method using two-frame subtraction

Abstract: MOVING TARGET DETECTION METHOD USING TWO-FRAME SUBTRACTION ABSTRACT OF THE DISCLOSURE A method and apparatus for detecting an object of interest against a cluttered background scene. In a first preferred embodiment the sensor tracking the scene is movable on a platform such that each frame of the video representation of the scene is aligned, i.e., appears at the same place in sensor coordinates. A current video frame of the scene is stored in a first frame storage device (14) and a previous video frame of the scene is stored in a second frame storage device (20). The frames are then subtracted by means of an invertor (24) and a frame adder (28) to remove most of the background clutter. The subtracted image is put through a first leakage reducing filter, preferably a minimum difference processor filter (32). The current video frame in the first frame storage device (14) is put through a second leakage-reducing filter, preferably minimum difference processor filter (36). The outputs of the two processors are applied to a two quadrant multiplier (42) to minimize the remaining background clutter leakage and to isolate the moving object of interest. In a second preferred embodiment the sensor does not track the scene and therefore the frames of video from the two storage devices (140, 200) must be aligned before the subtraction process can occur. The alignment function is performed by a background registration correlator (150) and a frame shifter (130). Once the two frames of video data are aligned they are then subtracted and preferably applied to the minimum difference processor filters (320, 360) as with the first embodiment. The outputs of the two minimum difference processors (320, 360) are again applied to a two quadrant multiplier (420) to eliminate the remaining background clutter.

A parallel algorithm for 3D point pattern matching

Abstract: The authors present a parallel algorithm for determining the correspondence between two sets of three-dimensional (3D) object feature points, referred to as frame 1 and frame 2, respectively. The points in frame 1 and frame 2 are obtained by observing the same dynamic scene (with multiple rigid objects), at two different instants of time. The parallel algorithm presented is adaptive, i.e. it works with a variable number of processors, and it uses a relatively weaker (and cheaper) model of parallel computation, namely, single-instruction multiple-data (SIMD) with shared memory blocks. The algorithm segments the scene based on difference in motion parameters. The approach is robust in the sense that it does not require the number of points in frame 1 and frame 2 to be identical. >

Data packet format in HDLC protocol with retransmission of frames having an error

Abstract: A protocol and data packaging format optimized for transmissions over noisy communications links is disclosed. The data packaging format provides a modified High-level Data Link Control (HDLC) control mechanism incorporated into a normal data communication header thus eliminating the requirement for control messages to acknowledge or reject transmissions. An eight bit value is used to encode a toggle bit status for each of eight possible transmit sequence numbers. The eight bit value when used alone, constitutes a null frame indicating data-free feed-back. The null frame is used to confirm receipt of data frames. This eight bit value is also used as the first byte of every data frame. The second byte of the data frame consists of a four-bit logical channel index, a single bit transmit toggle bit and a three-bit transmit sequence number. The second byte of the data frame may be followed by zero or more eight-bit data bytes. When a data frame arrives at a receiver, the bit value of the transmit toggle bit is copied into one of the eight bits of the first byte according to the transmit sequence number. The receiver sends the newly modified first byte back to the sender as part of a data frame transfer or as a null frame to confirm receipt of the data frame.

Optimization of multirate filter banks within the framework of a human visual model

Abstract: A perfect reconstruction filter optimization based on a human visual model is presented. The optimized filters are compared to a set of published filters for coding at a fixed bit rate. A method is suggested for adapting the filters to change in source statistics. This method is applied to coding of intraframe data and residual frame data after motion-compensated prediction. >