Samsung Electronics Co., Ltd.

Korea University Industrial Academic Collaboration Foundation

Kwan-Woong Song

Seong-Taek Hwang

Yun-Je Oh

Young-hun Joo

Kwang-pyo Choi

Chang-su Kim

Young-O Park

Sung-Jin Park

Jun-Ho Koh

Tae-Sung Park

Yong-Deok Kim

Jae-Kyun Ahn

Sang-Ho Kim

Sung-Tae Kim

Jeong-seok Choi

Han-Sang Kim

Shin-Hee Won

Seong-Ha Kim

Se-Hong Park

Young-Hoon Joo

A method for estimating a boundary between a background and a user object in a video, in which the user object is segmented from the background is provided. The initial object contour is estimated in a first video frame for object segmentation, and color probability density functions are estimated for the user object and the background segmented from the first video frame. An edge strip with a predetermined width is generated in a current frame based on an object contour of a previous frame, and a coherence probability density function of the edge strip is estimated. The user object is segmented in the current frame by energy minimization.

Method for estimating contour of video object

A method and apparatus for estimating the contour of a user object in a moving picture during video communications so that a personal background image is not provided during video communications. Information about center coordinates as well as a size of a face of the user object is extracted from a moving picture frame. Edges are extracted from the moving picture frame, and a boundary of a head of the user object is estimated using a semicircle. The boundaries of left and right shoulders and left and right arms of the user object are estimated using second-order function graphs that overlap a largest portion of the edges. An entire contour of the user object is estimated according to the boundaries of the head, the left and right shoulders, and the left and right arms of the user object.

Method and apparatus for estimating object contour in a moving picture

A method and apparatus for error concealment in decoding of a moving picture. The method includes the steps of determining an erroneous macro block in a present frame when the moving picture is decoded, finding a first macro block having a highest similarity to the erroneous macro block and a second macro block having a next highest similarity to the erroneous block in a previous frame by comparing adjacent pixels of respective blocks in the previous frame with adjacent pixels of the erroneous block in the present frame; and replacing the erroneous block by using an average between the found macro blocks having the highest similarity and the second highest similarity to thereby conceal the erroneous macro block. The apparatus includes a parser, an entropy decoder, an inverse quantizer, an inverse converter, and a concealment unit that uses motion compensation from a previous frame to correct a macro block in a current frame.

Method for error concealment in decoding of moving picture and decoding apparatus using the same

Disclosed are a system and method for providing digital multimedia broadcasting confinement service. The system includes: a relay center side system, which is adopted to the relay center, according to the relay center side packet identification description (PID) key, for modifying the PID of transport stream and generating the distorted program specific information (PSI); and a terminal side system, which is adopted to the DMB terminal, according to the terminal side PID key, for recovering the distorted PSI of the transport stream received from the relay center and decoding it. The method includes the steps of: identifying whether the actual PID of the TS is consistent when the TS is demultiplexed by audio/video PID acquired through the program map table (PMT) analysis of the TS; generating a preset alarm signal; modifying the PID of the audio/video data in the PMT according to the terminal side PID; and demultiplexing the TS according to the modified PID value.

System and method for digital multimedia broadcasting confinement service

Disclosed is a wide-band fiber amplifier for amplifying C-band and L-band optical signals, including a first amplifying unit including a first amplifying fiber adapted to be (1) pumped in at least one direction (2) amplify both the C-band and L-band optical signals and (3) output Amplified Spontaneous Emission (ASE), a second amplifying unit including a second amplifying fiber adapted to be pumped by amplified ASE and secondarily amplify the amplified L-band optical signal, and an L-band pumping light source including a third amplifying fiber adapted to be pumped in at least one direction while being pumped by the ASE, and output amplified ASE used to pump the second amplifying fiber.

Wide-band fiber amplifier

Disclosed wideband optical fiber amplifier amplifies and outputs wideband optical signal containing C-band and L-band optical signals. The amplifier includes: a first amplification section amplifying the wideband optical signals; a second amplification section amplifying the separated L-band optical signals amplified by the first amplification section; an optical signal coupler combining and outputting the optical signals amplified by the first and second amplification sections; and an optical circulator. A first port of the optical circulator inputs the wideband optical signals from the optical communication network; a second port outputs the inputted wideband optical signals and inputs spontaneous emissions generated from the first amplification section; a third port provides the spontaneous emissions to the second amplification section while inputting the L-band optical signals amplified by the second amplification section; and a fourth port outputs L-band optical signals that were inputted to the third port to the optical signal coupler.

Wideband optical fiber amplifier

Disclosed is a gain-controllable wideband optical fiber amplifier for amplifying both C-band and L-band optical signals, which comprises: a first amplifying section configured to (1) be pumped in at least one direction, (2) amplify both C-band and L-band optical signals and (3) output an amplified spontaneous emission; an optical attenuator for attenuating the power of the spontaneous emission; and a second amplifying section pumped by the attenuated spontaneous emission to secondarily amplify the amplified L-band optical signals.

Gain-controllable wideband optical fiber amplifier

There is provided an optical signal monitoring method and apparatus for measuring the characteristics of an input WDM optical signal. In the optical signal monitoring method, the WDM optical signal is combined with reference lights at both sides of the WDM optical signal on the wavelength spectrum. The combined signal is input to a filter having a variable transmission wavelength according to an applied driving voltage. A driving voltage-light intensity graph of a combined optical signal detected from the filter is derived in its overall wavelength band. A linear approximated wavelength is obtained with respect to a driving voltage and a non-linear compensated wavelength is calculated in a predetermined non-linear compensation formula with the driving voltage and the operation temperature of the filter.

Method and apparatus for monitoring WDM optical signal

An automatic gain controller for controlling gain values of an optical fiber amplifier. The automatic gain controller includes a first opto-electric conversion unit for converting a portion of optical signals that are input into the optical fiber amplifier into electrical signals to output the converted electrical signals. A second opto-electric conversion unit converts a portion of output optical signals output from the optical fiber amplifier into electrical signals and then outputs the converted electrical signals. A transient suppressing unit generates pulse typed waveforms when a change in channel number is generated during monitoring outputs of the first opto-electric conversion unit, and a comparing unit compares the sum of output signals of the transient suppressing unit and output signals of the first opto-electric conversion unit with output signals of the second opto-electric conversion unit. A control unit outputs pump control signals in response to the output signals of the transient suppressing unit and output signals of the comparing unit, and a first pumping light source unit supplies pumping light to the optical fiber amplifier in response to the inputting of the pump control signals.

Automatic gain controller of optical fiber amplifier

A wide band erbium-doped fiber amplifier with a gain enhancement is provided comprising a first fiber amplifier adapted to amplify C-band components of an input optical signal, a second fiber amplifier connected to the first fiber amplifier in series while being disposed downstream from the first fiber amplifier to amplify L-band components of the input optical signal. A C/L splitter is disposed between the first and second fiber amplifiers and to split the amplified C and L-band optical signals to flow along different paths. A fiber reflector is disposed downstream from the second fiber amplifier to reflect the amplified L-band optical signal to flow backwards toward the second fiber amplifier. A circulator is disposed between the C/L splitter and the second fiber amplifier to guide the amplified L-band optical signal, reflected to flow backwards by the fiber reflector, so that the amplified L-band optical signal flows along a path different from that of optical signals applied to the circulator. A C/L combiner combines the amplified C-band optical signal split by the C/L splitter with the amplified L-band optical signal guided by the circulator, and applies the resultant optical signal to an output stage.

Wide band erbium-doped fiber amplifier with gain enhancement

The present invention discloses a long-band Erbium doped-fiber amplifier including: a first Erbium doped fiber with a predetermined length, coupled to a first pumping light source through a first wavelength-selective coupler, for amplifying a C-band optical signal by supplied pumping light; a second Erbium doped fiber with a predetermined length for amplifying an L-band optical signal by a second pumping light source; a feedback loop for recycling a specific C-band wavelength generated in the amplification of the first Erbium doped fiber as the second pumping light source of the L-band optical signal; a tap coupler formed between the first and second Erbium doped fibers, for dividing the optical power amplified in the first Erbium doped fiber, for supplying a predetermined ratio of optical power to the second Erbium doped fiber, and for re-inputting the residual optical power to the feedback loop; and, a second wavelength-selective coupler for coupling the signal light transmitted from the tap coupler to the first Erbium doped fiber.

Long-band erbium doped fiber amplifier

Disclosed is a wide band optical fiber amplifier for amplifying C and L-band optical signal components having an economical configuration, high amplification efficiency while exhibiting a low noise figure. The amplifier includes first and second isolators; first, second, and third amplification units; a distributor; a gain flattening filter; and first and second reflectors. The amplifier receives C and L band optical signals and process the signals by: amplifying C and L band signals; gain flattening the only C band signal twice; amplifying C and L band signals for the second time; splitting the C band signal from L band signal; subjecting L band signal to be amplified three more times; and combining resulting C and L band signals.

Wide band optical fiber amplifier

Disclosed is an L-band optical amplifier for amplifying optical signals with the wavelength band of the L-band. The L-band optical amplifier comprises an optical-amplifying section for emitting spontaneous emission and for amplifying the optical signals by pumping of the spontaneous emission, a mirror for reflecting the optical signals amplified by the optical-amplifying section to re-enter back to the optical-amplifying section, and a feedback loop connected with both terminals of the optical-amplifying section for causing spontaneous emission emitted from the optical-amplifying section to be fed back to the optical-amplifying section.

L-band optical amplifier

The present invention is directed to a bidirectional add/drop multiplexer connected with waveguides at opposite ends thereof, respectively, and adapted to add/drop a channel in forward and reverse directions. The multiplexer includes a forward arrayed waveguide grating for demultiplexing the respective channels of the forward optical signal inputted thereto, for adding or dropping a channel to the demultiplexed channels of the forward optical signal, and for multiplexing the channel-added or dropped channels; a reverse arrayed waveguide grating for demultiplexing respective channels of the reverse optical signal inputted thereto, for adding or dropping a channel to the demultiplexed channels of the reverse optical signal, and for multiplexing the channel-added or dropped channels; a first circulator for inputting the forward optical signal to the forward waveguide grating and outputting the reverse optical signal received from the reverse waveguide grating to one of the waveguides, and, a second circulator for inputting the reverse optical signal to the forward waveguide grating and outputting the forward optical signal received from the forward waveguide grating to the other waveguide. Using this arrangement, the bidirectional add/drop multiplexer is capable of cutting off the relative intensity noise while avoiding the collision of the forward and reverse optical signals.

Growing community of inventors

Seoul, South Korea

Kwan-Woong Song