Nec Corporation

Nippon Electric Co., Ltd.

Nec Home Electronics, Inc.

Nippon Telegraph and Telephone Corporation

Fujitsu Corporation

Mitsubishi Denki Kabushiki Kaisha

Kokusai Denshin Denwa Co., Ltd.

Toshio Koga

Junichi Ohki

Mutsumi Ohta

Naoki Mukawa

Hideto Kunihiro

Masayuki Okajima

Kiichi Matsuda

Akira Hirano

Yoshinori Hatori

Akihiro Furukawa

Kazumoto Iinuma

Masahide Kaneko

Yoshihiro Miyamoto

Yoshiaki Nozawa

Hirohisa Shiojiri

Hideo Hashimoto

Sakae Okubo

Hideto Kunhiro

Jun'ichi Ohki

A vehicle-onboard ETC apparatus capable of conducting ETC information communication includes a vehicle speed detector for detecting a speed of a motor vehicle which passes through a toll gate station equipped with an ETC system, a communication unit for exchanging ETC information for settlement of toll charge/payment with the toll gate station upon passing therethrough, a measuring unit for measuring reception field intensity of the received ETC information within a communication coverage area, and a decision unit for making decision on the basis of the detected vehicle speed and the measured reception field intensity as to a location within the communication coverage area where ETC information communication can be started while sustaining favorable field intensity for signal reception at the detected vehicle speed, to thereby allow the communication means to perform communication processing on the basis of the result of the above decision.

Vehicle-onboard ETC apparatus

A vehicle-onboard ETC apparatus mounted on a motor vehicle which informs a driver of ETC-relevant information interchanged with an ETC facility installed at a toll gate via an image as well as a voice, and which requires minimal extension of hardware. The apparatus determines and discriminates field intensity for received ETC-relevant information without using any specific measuring apparatus, while outputting the field intensity information as an image or voice. The apparatus includes a communication unit for interchanging toll charge/payment information with the ETC facility of the toll gate when the motor vehicle passes through the toll gate, signal conversion means for converting the received toll charge/payment information into an image signal and a voice signal, a display device for displaying the image signal resulting from the conversion, and a voice signal output unit for outputting the voice signal resulting from the conversion through an audible signal converting unit.

Vehicle-onboard ETC apparatus and method with visible/audible ETC-relevant information messaging

A data processor includes a first encoder, a first storage medium, a subtracter, a second encoder, a second storage medium, and an output section. The first encoder generates, by using a predetermined first coding method, a main code prepared by encoding a moving picture signal input as an original signal. The first storage medium stores the main code generated by the first encoder. The subtracter calculates a coding distortion generated upon coding by the first encoder. The second encoder encodes, by using a predetermined second coding method, the coding distortion calculated by the subtracter, thereby generating a compensation code. The second storage medium stores the compensation code generated by the second encoder. The output section outputs the main and compensation codes respectively stored in the first and second storage media.

Data processor and data receiver

An image signal encoding system which is capable of correctly encoding an editing image signal before and after switching points of a first input dynamic image signal and a second input dynamic image signal. The image signal encoding system selects, as an editing image signal, one of the first and the second input dynamic image signals, each of which has serial image plane frames to encode the editing image signal. A switching signal is produced which is used to select as the editing image signal one of the first and second input dynamic image signals. An image encoder encodes the editing image signal, using spatial correlation, an initial image plane frame of the editing image signal after a switching time point of selection of the first and second input dynamic image signals. The image encoder encodes, using previous forecast in correlation between two successive image plane frames of the serial image plane frames, a final image plane frame before the switching time point of selection of the first and second input dynamic image signals.

Image signal encoding system capable of correctly encoding an editing

A method of adaptively multiplexing a plurality of video channel data is disclosed. A multiplexed data includes a plurality of frames each of which contains a plurality of sub-frames. The video channel data are adaptively allocated to the sub-frames. A memory occupancy value of a buffer, which is provided in each of a plurality of video channels, is determined. The buffer is arranged to receive the corresponding video information. A plurality of control signals are produced each of which indicates the memory occupancy value of the corresponding buffer. Following this, a look-up table is accessed which includes a plurality of video channel assignment data for assigning the video channel data to The sub-frames. Thus, one of the channel data assignment data is derived from the look-up table. The video channel data are then multiplexed using one of said channel data assignment data derived from the look-up table.

Method of adaptively multiplexing a plurality of video channel data

A multiplex transmission method and apparatus for motion picture signals. A transmission line constituted by transmission channels having different carrier frequencies is prepared. One of the transmission channels has a transmission rate almost equal to the long-term average of information generation speeds in encoding an arbitrary motion picture signal. The input motion picture signal is encoded by using inter-frame and intra-frame correlations, and encoded information is output for each image channel. The image channels are related in one-to-one correspondence with the transmission channels having the different carrier frequencies. When an image channel of interest, of the image channels, exhibits a large generated information amount representing the encoded information generation speed within a time interval determined by a predetermined transmission rate of the transmission line in advance, adaptive multiplexing is performed by dividing and distributing the encoded information of the image channel of interest to the transmission channels including the transmission channel of the image channel of interest. The encoded information divided/distributed by the adaptive multiplexing is transmitted for each allocated transmission channel.

Multiplex transmission method for motion picture signals and apparatus

In a transmitting system, a first multiplexer multiplexes first through M-th encoded digital video signals from encoders to produce a primary multiplex signal comprising cells which have channel codes, address codes, and cell data, where M represents an integer greater than two. Each of the cell data represents a part of one of the encoded digital video signals. Each of the channel codes indicates one of the encoded digital video signals. Each of the address codes indicates a position of one of the cell datum. A first demultiplexer demultiplexes the primary multiplex signal to produce first through N-th primary demultiplex signals, where N represents an integer which is less than M and greater than one. A second multiplexer multiplexes the first through the N-th primary demultiplex signals from the first demultiplexer through first through N-th transmitting paths to produce a secondary multiplex signal. A second demultiplexer demultiplexes the secondary multiplex signal datum in response to the channel codes and the address codes to produce the first through the M-th encoded digital video signals.

Transmitting system having transmitting paths with low transmitting rates

In the time-varying image signal coding apparatus, a local encoded signal is quantized by a quantizing circuit, and the quantized signal is selected when refreshing is to be accomplished, and subjected to code transform by a code transform circuit to be transmitted to a time-varying image signal decoding apparatus. The signal supplied from the quantizing circuit is a transform coefficient in the transform region, and this is divided into a plurality of groups to be refreshed on a group-by-group basis. The transfer control on a group-by-group basis when refreshing is to take place is accomplished with a control signal supplied from a switching control circuit, and this control signal also undergoes code transform by the code transform circuit to be transmitted to the time-varying image signal decoding apparatus. In the time-varying image signal decoding apparatus, in accordance with the switching control signal transmitted from the time-varying image signal coding apparatus, refreshing is achieved by such selection that the transform coefficient to be refreshed is directly written into a frame memory from a code inverse transform circuit. When a time-varying image signal is to be transferred by using interframe transform and transform coding, grouping is achieved by the units of transform coefficient, and frames are rewritten with each group independent of others.

Time-varying image signal coding/decoding system

A time-varying image signal coding apparatus including a local encoded signal being quantized by a quantizing circuit, and the quantized signal is selected when refreshing is to be accomplished, and subjected to code transform by a code transform circuit to be transmitted to a time-varying image signal decoding apparatus. The signal supplied from the quantizing circuit is a transform coefficient in the transform region, and this is divided into a plurality of groups to be refreshed on a group-by-group basis. The transfer control on a group-by-group basis when refreshing is to take place is accomplished with a control signal supplied from a switching control circuit, and this control signal also undergoes code transform by the code transform circuit to be transmitted to the time-varying image signal decoding apparatus. In the time-varying image signal decoding apparatus, in accordance with the switching control signal transmitted from the time-varying image signal coding apparatus, refreshing is achieved by such selection that the transform coefficient to be refreshed is directly written into a frame memory from a code inverse transform circuit. When a time-varying image signal is to be transferred by using interframe transform and transform coding, grouping is achieved by the units of transform coefficient, and frames are rewritten with each group independent of others.

In the time-varying image signal coding apparatus, a local encoded signal is quantized by a quantizing circuit, and the quantized signal is selected when refreshing is to be accomplished, and subjected to code transformation by a code transform circuit to be transmitted to a time-varying image signal decoding apparatus. The signal supplied from the quantizing circuit is a transform coefficient in the transform region, and this is divided into a plurality of groups to be refreshed on a group-by-group basis. The transfer control on a group-by-group basis when refreshing is to take place is accomplished with a control signal supplied from a switching control circuit, and this control signal also undergoes code transformation by the code transform circuit to be transmitted to the time-varying image signal decoding apparatus. In the time-varying image signal decoding apparatus, in accordance with the switching control signal transmitted from the time-varying image signal coding apparatus, refreshing is achieved by such selection that the transform coefficient to be refreshed is directly written into a frame memory from a code inverse transform circuit. When a time-varying image signal is to be transferred by using interframe transform and transform coding, grouping is achieved by the units to transform coefficient, and frames are rewritten with each group independent of others.

Time-varying picture signals of a plurality of channels are predictively coded by utilizing the interframe correlation and multiplexed at the transmitting side. The signals are separated for each channel, switched and selected for any channel for decoding at the receiving side after transmitted. When the receiving channel is switched over to other channel, a decoding error can occur and a reproduced screen can collapse since the predicting signals do not coincide with each other at the transmitting and receiving sides. Therefore, when the plurality of channels is selectively switched for decoding by using a single decoder, the refresh is repeated at predetermined time intervals in a short period of time by utilizing the intraframe correlation when the coding is carried out at the transmitting side so that, even if the channel is switched, an excellent reproduced screen may be immediately obtained. However, during the refresh, the compression ratio is reduced compared with that of the bit rate when a normal interframe correlation is carried out. Therefore, when the refresh is carried out, the amount of transmitted information for part or all of the channels other than the refreshed channel is compressed and, conversely, the amount of transmitted information for the refreshed channel is increased by the compressed amount and allocated. Thus, even if the channel is switched at the receiving side, the decoded image for the newly selected channel can be promptly reproduced.

Method and apparatus for multiplex transmission of video signals in a

On detecting a drastic change, such as a scene change, between current and previous ones of successive pictures which are represented by a digital video signal and each of which comprises a predetermined number of picture elements, the digital video signal is processed by using correlations between the picture elements within each of the successive pictures to produce a processed signal which represents processed results for each of the successive pictures. A statistical distribution of the processed results is calculated from the processed signal. The statistical distribution of the processed results in the current picture is collated with the statistical distribution of the processed results in the previous picture to be produced as a change detection signal representative of the drastic change with reference to a relationship between the statistical distribution of the processed results in the current picture and the statistical distribution of the processed results in the previous picture. The processed signal may be obtained by producing a difference signal between the digital video signal and a prediction signal predictive of the digital video signal by using the correlations. Alternatively, an orthogonal transform is carried out for the digital video signal to produce the processed signal.

Accurate detection of a drastic change between successive pictures

In a reproduction system for use in reproducing a still image from a sequence of predictive error signals which is read out of a memory and which is preliminarily processed into a sequence of preliminary processed signals, an intermediate circuit interrupts the preliminary processed signals in response to an external command signal. In the intermediate circuit, the external command signal is resampled by a sequence of frame pulses in a resampling circuit into a resampled signal so as to close a gate circuit. No predictive error signal is sent to an adder circuit during absence of the gate circuit. An identical error signal is repeatedly produced as a sequence of reproduced signals to reproduce the still image.

Reproduction system capable of reproducing a still image by interrupting

In a decoding system for decoding video signals into original video signals, the requirement for an externally-arranged frame synchronizer is avoided. The decoding system itself incorporates a frame synchronization function. In one form, the decoding system comprises a buffer memory for temporarily storing video signals that have coded by a predetermined coding algorithm. A frame sync signal detector detects frame sync signals out of the video signals temporarily stored in the buffer memory and generates sync detection signals. A reference sync signal detector detects reference sync signals provided from outside and generates reference sync detection signals. A decoder is responsive to the frame sync and reference sync detection signals to read the video signals out of the buffer memory and to decode the video signals.

Video signal decoding system having a frame synchronizer function

In an image processing system for use in processing a sequence of image signals carrying a moving image, the image signal sequence is divided into a sequence of partial image signals each of which carries a scene subsequence defined by scene changes. A background signal generator determines a background portion of the moving image by monitoring a whole of each partial image signal and produces a background signal. The background signal is coded by a coder prior to a sequence of error signals resulting from predictive coding of each partial signal. During prediction of the background signal, the error signals may be rendered to zero in the coder. The background signal may be either determined at every picture element or at every block composed of a plurality of picture elements.

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Tokyo, Japan

Toshio Koga