Showing papers on "Inter frame published in 1986"

Low bandwidth video teleconferencing system and method

Abstract: A low bandwidth video teleconferencing system and method is disclosed. The video teleconferencing system employs novel data compression techniques by which continuous transmission of imagery at a rate of 9600 bits/second is possible. A sketch coder converts the grey scale image to be transmitted to a sketch or line drawing, which comprises an outline of the principal boundaries plus shading to represent depth. The bandwidth required for the data representing the sketch is then compressed by two-dimensional run length coding techniques which exploit interframe and interline redundancy as well as intraline redundancy to generate a binary transmission code. Other features are also provided.

Hybrid coding system for moving image signal

Abstract: PURPOSE:To minimize the reduction of coding efficiency and the deterioration of picture quality by selecting either of a predictive error signal or an input picture signal between frames by means of an error evaluation quantity per block and evaluation quantity of predication error signal between the frame, and executing an orthogonal conversion coding. CONSTITUTION:The difference of the input picture signal supplied from a signal line 11 with an interframe predicative or an action compensation predicative value is taken in a computing element 100, and an interframe predicative error signal is obtained. The predicative error signal and the input picture signal are transmitted to a valid/invalid decision part and an interframe/frame internal selection part 1000. Delay circuits 200 and 201 correct delayed signals occur in the selection part 1000, and a switch 300 selects and outputs either of the interframe predicative error signal or the frame internal signal both of which had been switched and controlled based on the output signals 1100 and 1101 from decision and selection part 1000. A selected signal 14 is inputted to an orthogonal conversion part 400, is orthogonal-converted, and is quantilized. Thus, the reduction of coding efficiency and the deterioration of picture quality can be minimized.

A Motion-Compensated Interframe CODEC

Abstract: This paper describes an adaptive intra-interframe codec with motion-compensation followed by an entropy coding for prediction error signal as well as for motion vector information. This adaptive prediction is highly efficient even for very fast motion as well as scene change where motion compensation is ineffective. Prediction error and vector information are code-converted for transmission by means of an entropy coding where contiguous zero signal is run-length coded and non-zero signal is Huffman-coded. Based upon the algorithms described in this paper a practical codec has been developed for videoconference use at sub-primary rate. According to a brief subjective evaluation, the codec provides good picture quality even at a 384 kb/s transmission bit rate.

Method for converting interlaced video signals into non-interlaced video signals and video signal converter for implementing this method

Abstract: Method for converting interlaced video signals into non-interlaced video signals, the said video signals being available in the form of successive digital samples associated with each point of a starting image. This method comprises: a. a first operation for detecting inter-image motion; b. a second operation for estimating motion by searching, for each block of the current frame, for the best possible correlation between the current block considered in this current frame and a series of blocks considered in succession in the preceding frame T-1, the estimated motion then being that which leads to the said current block from the block of frame T-1 and for which the correlation is effectively the best; c. a third operation of vertical interpolation for the generation within the current frame of intermediate lines between the existing lines; d. a fourth operation for selecting the value to be associated with each point of the lines to be generated in each block of the current frame, from three specified values; e. a fifth operation of final image reconstruction. Application: video signal converters for high-definition television.

Animation communication system

Abstract: PURPOSE: To obtain an electronic conference system having no error in transmission and rich in a real time property by encoding, transmitting and decoding based on the preceding picture data when the error is generated. CONSTITUTION: When the error in transmission is generated on a line and the generation of the error in transmission is informed by a transmission control frame, the comparison with a present using frame memory from the next time is performed to information capable of being effectively reproduced in a receiving side, namely a reference frame memory preceding by two. When the transmision control frame of the error in transmission is received, a frame error R signal is active, the second reference frame memory 338 is fed from a reference frame part 335 to perform the comparison with the present using frame. The contents of the second frame memory 338 are transferred to the first reference frame memory 337. COPYRIGHT: (C)1987,JPO&Japio

Yc separator circuit of television signal

Abstract: PURPOSE:To simplify a device by providing a noise reduction function with use of a conventional frame memory, and utilizing an indispensable chrominance subcarrier phase inverter (chroma-inverter) as a noise reducer instead of applying independently the YC separation between lines. CONSTITUTION:A chroma-inverter for utilizing the YC separation between lines is formed by a 1H memory 315, attenuators 316 and 317, adder 318, BPF319, amplifier 320 and subtracter 321. A signal with three taps is obtained from an output signal of the subtracter 312 in the memory 315, and a chrominance signal is separated in the same manner as the interline YC separation. Both inputs of the subtracter 314 turn out to be signals which have matching phases of chrominance signals and are spaced by one frame. At this time, an output of the subtracter 314 corresponds to a difference signals 314a between frames. On a still picture plane, noise without frame correlation become difference signals, appear at the signal 314a and canceled in the subtracter 312. On the other hand, the interframe difference signal 314a goes to a remarkably high level on an animation, while an output of a coefficient device 313 goes to zero. Accordingly the information in the previous frame is completely eliminated, and will not affect frames afterward.

Adaptive forecast coding device of inter-frame and between frames of animation picture signal

Abstract: PURPOSE:To improve the coding efficiency by using an input signal to apply inter-frame forecast with respect to a predetermined still region and apply adaptive forecast with respect to an animation region regardless of the decision result of the adaptive forecast system. CONSTITUTION:A frame memory 10 retards an input animation picture signal by 1 frame time, a subtractor 11 calculates frame difference, an adder 12 calculates the total sum of frame difference absolute value of a picture element in a clock, a comparator 13 compares the sum with a prescribed threshold value and outputs the result as animation/still information. A subtractor 14 outputs a difference between the input signal and a forecast signal from a selector 17 to a quantizer 15 as a forecast error. A discriminator 20 decides the inter-frame forecast when the animation/still information from the comparator 13 represents the still region and the picture element forecast system when not, and the selector 17, according to the forecast system, selects one of plural forecast signals from a forecast circuit 18. A code converter 16 converts a quantized forecast error signal and the animation/still information into a proper code and outputs the result.

Encoding device for inter-frame adaptive vector quantization

Abstract: PURPOSE: To show an enough noise smoothing effect at a dynamic area, and to prevent the generation of an unnecessary encoding data at a static area by applying an adaptive control on a smoothing characteristic in an adaptive spatial filter. CONSTITUTION: An input picture signal 13 is digitized at an AD converter 1, and a vector data 14 can be obtained at a raster/block scanning conversion circuit 2. The vector data 14 is subtracted a preceding frame vector 15 in which an adaptive spatial filter 8 is applied on a preceding frame vector 23 within a frame memory 7, and an inter-frame differential input vector 16 can be obtained. The smoothing characteristic of the adaptive spatial filter 8, similarly as a threshold value control for a motion detection circuit 4, is controlled by every frame with a parameter 24 corresponding to a data quantity within a transmission data buffer 5. A vector quantization encoder 3 encodes the inter- frame differential input vector 16 decided as effective, and an encoding data 17 is written at the transmission buffer 5. COPYRIGHT: (C)1987,JPO&Japio

Detector for inter-frame motion vector of television signal

Abstract: PURPOSE:To simplify a circuit constitution by utilizing the statistical characteristics of a picture image, estimating the motion vector of the present block from that of the block detected and detecting the motion vector within the range of the estimated value. CONSTITUTION:The signal in the previous TV frame which is delayed by a frame memory 1 is also delayed by a line memory 2 and a 1 picture element delay element 3. A multiplexer 11 selects several signal (9, in this case) which are corresponded with the motion vector of the block just before out of 25 TV signals in the previous TV frame and by a differential circuit 4, it calculates the difference between the TV signal of the present TV frame with those of the above TV signals. The difference value is compared at a comparison circuit 5 and the difference value which has the strongest correlation with the present frame is selected, and the sum of the value and the motion vector of the block just before are calculated by an adder 12 and an actual motion vector is calculated. By the result of the above calculation, the delay volume in a delay circuit 6 is controlled and is inputted to an encoding circuit 7 resulting an encoding. Also, the result of the calculation is delayed by one block for the estimation of the motion vector in the next block by a delay circuit 13.

Method and device for inter-frame estimated coding system of animation signal

Abstract: PURPOSE:To improve greatly the background picture quality and to suppress the effect of noises produced at a static area, by separating a mobile area from a static area within a screen and applying the rough quantization to the static area with the fine quantization applied to the area where the mobile area is changed to the static area respectively. CONSTITUTION:A subtractor 13 produces a frame difference, i.e., an estimated error signal from an input signal and an estimated signal supplied via a line 1413. This error signal is outputted to a quantizer 16. The quantizer 16 outputs the quantization output of the estimated error to a comparator 17 when no subsample is designated and then zero to the comparator 17 when the subsample is designated respectively. The comparator 17 sets the absolute value of the quantized estimated error at zero when said absolute value is smaller than the dead zone designated value and the absolute value is outputted as it is when the absolute value is larger than said dead zone designated value. AN adder 18 adds the estimated error and the estimated signal together. An interpolation circuit 15 receives the interpolation from the local decoded signals of peripheral picture elements when the notice picture element is sampled. While the picture element is outputted as it is to a frame memory 14 when it is not sampled.

Inter-frame coding device

Abstract: PURPOSE:To reduce a quantity left widely and to improve a quality of a picture by outputting a coding signal obtained at a coding circuit and a smoothing circuit smoothed, and installing a transmitting buffer memory circuit which outputs an over-flow signal due to an overage of an information quantity. CONSTITUTION:An analog picture signal inputted from an input terminal 11 is converted to a digital PCM signal a1 by an A/D converting circuit 1 and inputted to an input frame memory circuit 9. When the input frame memory circuit 9 executes an ordinary inter-frame coding processing, the merely written data are read as they are and a reading signal b1 is outputted to a coding circuit 2 as a digital picture signal. When an over-flowing occurs, a transmitting buffer memory circuit 10 outputs an over-flowing signal OVF to the input frame memory circuit 9, and an action of a receiving part shown in Fig. (b) to prohibit a data writing to the same circuit is the same as the conventional example.

Interframe encoding system

Abstract: PURPOSE:To reduce deterioration in picture quality and to obtain a high- compressibility system by separating a motion picture signal into a motion area and a still area when an image signal is transmitted digitally, and quantizing roughly predicted errors of picture elements in the still area and also quantizing one image plane finely at every constant period CONSTITUTION:An adder 5 adds the quantized predicted error signal to a prediction signal from a frame memory 6 and supplies the result as a local decoded signal to the frame memory 6 A quantization switch 701 outputs a quantization switching signal which normally selects rough quantization for a part determined as the still area with a motion/still decision signal supplied from a motion/still separating circuit 2 through a signal line 201 and also outputs a quantization switching signal which selects fine quantization for the whole of the still area when a timing signal is sent from a timer 702 Thus, the rough quantization is normally performed by utilizing the motion/still decision signal and buffer occupancy and the whole still area is quantized finely upon occasion

System and device for inter-frame estimation coding of animation picture signal

Abstract: PURPOSE:To provide an estimation coding system with a less picture deterioration in a quiescing area and with a high compression rate by separating a moving area and a quiescing area of a moving picture, by counting a distance between the quiescing area and the moving area for a picture element included in the quiescing area, and by executing quantization coursing in proportion to increasing of said distance. CONSTITUTION:Besides that the animation picture signal inputted from a line 1000 is supplied to a delay circuit 16, it is also supplied to a subtractor 11 and a frame memory 10. A comparator 13 compares the magnitude of the above signal with a prescribed threshold level and outputs to a quantization control circuit 14 as a moving/quiescing information through a line 100. A delay circuit 16 delays an input signal for a time necessary to judge a moving/quiescing and to count the distance from the moving area and outputs this to a subtractor 17 and after counting a variance between the output signal of the delay circuit 16 and an estimating signal supplied from a frame memory 20, the result is outputted to a quantizer 18 as an estimated error, also to a code convertor 21 and an adder 19.

Interframe Contour Coding

Abstract: Contour coding can be applied with profit both to visual communication at very low data rates and to contour-texture techniques, as recent neurophysiological findings strongly suggest. The present paper aims at reducing the coding cost by removing the interframe redundancy. First therefore several intra-frame contour coding algorithms are investigated and attempts to single out those suitable for interframe extrapolation are made. The parameter encoding turned out to be the most appropriate. In fact it does not resort to a pel-by-pel descri'ption; on the contrary it resorts to a global description of the contour, which presents more moderate frame to frame changes. Then an interframe method is presented. It con-sists in a preliminary verification to see if the movement of a single contour is rigid, without any deformation, or not. In the first case the displacement is measured and transmitted; in the second case the changes experienced by the parameters chacterizing the contour are estimatet, coded and transmitted. The performance of this coder, tested by a typical videotelephonic sequence, is shown, and comments are made and a feasible strategy for further improvements is outlined.© (1986) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Temporal Propagation Of Channel Errors In Multimode Adaptive Coders

Abstract: The aim of this study is temporal propagation of channel errors in coding schemes for Television Sequences. Many studies have been performed to decrease spatial propagation in adaptive intraframe DPCM coder. All these methods could be extended to temporal domain. Briefly we distinguish, algorithmic robustness using efficient adaptive predictors, systematic protection with redundant information transmission, and the use of error correcting codes. This paper concerns more specifically the inherent robustness of coding algorithms. A multimode intraframe/interframe coding algorithm using motion compensation is used and the locii where channel errors are introduced for simulation experiments are precisely defined : fixed areas, motion compensated areas, uncompensated areas. First experiments show that high degree of adaptivity in the sense of fast switching between prediction modes (intra/interframe) must decrease the error propagation in both temporal and spatial domains. Moreover, correcting improvements such as temporal refleshment of specific parameters, especially motion parameters, have been tested.