Abstract: A buried semiconductor laser exhibiting a reduced dislocation of a contact layer is achieved. A buried semiconductor laser, comprising: an n-type indium phosphide (InP) substrate; an active layer disposed on the n-type InP substrate; block layers provided so as to bilaterally disposed on both sides of the active layer; a clad layer provided so as to cover the active layer and the block layers; and a p-type gallium indium arsenide (InGaAs) contact layer provided on the clad layer, wherein the p-type InGaAs contact layer has a compressive strain.

Abstract: In order to provide excellent device characteristics and enhance fabrication yield and run-to-run reproducibility in a buried device structure using a low mesa on a p-type substrate, a cross sectional configuration before growth of a contact layer of a device, i.e., after growth of an over-cladding layer is flattened so as not to cause a problem in crystal quality of the contact layer. A mesa-stripe stacked body including at least a p-type cladding layer (2), an active layer (4) and an n-type cladding layer (6) is formed on a p-type semiconductor substrate (1), a current-blocking layer (8) is buried in both sides of the stacked body, and an n-type over-cladding layer (9) and an n-type contact layer (10) are disposed on the current-blocking layer (8) and the stacked body. The n-type over-cladding layer (9) is made of a semiconductor crystal having a property for flattening a concavo-convex shape of upper surfaces of the current-blocking layer (8) and the stacked body.

Abstract: A unipolar semiconductor laser is provided in which an active region is sandwiched in a guiding structure between an upper and lower cladding layer, the lower cladding layer being situated on a semiconducting substrate. The unipolar semiconductor laser comprises a raised ridge section running from end to end between end mirrors defining the laser cavity. The ridge section aids in optical and electrical confinement. The ridge waveguide is divided in a plurality of cavity segments (at least two). Lattice structures can be arranged on and/or adjacent to these cavity segments. Each cavity segment is in contact with upper metallic electrodes. A metallic electrode coupled to the bottom surface of the semiconducting substrate facilitates current injection through the device.

Abstract: Systems and methods for high brightness, improved phase characteristics laser diodes.

Abstract: A laser mirror for a ring laser gyroscope (RLG) includes an intermediate optical coating, positioned within approximately a mid portion of the laser mirror for improving the performance of the RLG, and specifically for improving the reflectance of at least one wavelength emission. The properties of the intermediate optical coating and its placement within the laser mirror results in a good reflection of a first predetermined wavelength emission wavelength, for example a 633 nanometer wavelength emission, and a poor reflection of a second predetermined wavelength emission, for example a 650 nanometer wavelength emission. In one embodiment, the intermediate optical coating includes a half-wave or a multiple half-wave thickness and is made from Zirconium Oxide.

Abstract: A device for beam shaping is particularly suited for producing a linear intensity distribution in a working plane. The device includes a laser light source, which can emit a multi-mode laser radiation. The beam quality factor of the radiation with regard to a first direction perpendicular to the propagation direction of the laser radiation is greater than 1 and also the beam quality factor with regard to a second direction perpendicular to the propagation direction is greater than 1. The device further includes a beam transformation assembly, which are arranged in the device in such a way that they can transform the laser radiation or partial beams of the laser radiation in such a way that the beam quality factor with regard to the first direction is increased and that the beam quality factor with regard to the second direction is reduced.

Abstract: The invention provides a method for the determination of the phase change characteristics of a hazardous material, the method comprising optically recording images of a sample of the material and objectively evaluating the images. The phase change characteristics generally relate to a solid/liquid or liquid/solid phase change, and the method finds particular application in the determination of the crystallisation points of hazardous materials, most particularly radioactive materials. The images are typically recorded by means of a camera, and evaluated using a computer, which is able to objectively determine the point at which a phase change is first seen to occur, and thereby provide accurate, reliable and objective data.

Abstract: A patch having an infrared (IR) target is placed proximate to the surface of a mammal. The patch may include an insulator for protecting the target from exterior, ambient IR and may include bar codes or other indicia uniquely associated with either the patch or the mammal. The patch may also include a bio-reactive agent for indicating characteristics such as the pH of the mammal's skin. The patch may also include a thermometer for sensing the level of IR radiation from the IR target and may include a display of the temperature associated with such a level. The patch may also include a transmitter for wirelessly communicating information about such level to a remote location. A method of using the patch is also disclosed.

Abstract: A thermometer quick linkage apparatus comprises an elastic member, a button, a probe, and a chamber having one end provided with an opening for receiving the end portion of the probe, and the other end also provided with an opening for receiving the button. Within the chamber, one end of the elastic member connects with the button, and the other end thereof connects with the probe. The elastic member is configured such that, when the button is pressed to compress the elastic member to a certain degree, the end portion of the button comes into contact with the end portion of the probe, and when the button is pressed further down, the probe is pushed away from the chamber. The apparatus is simplified in structure, and allows quick replacement of the probe jacket, and therefore is cost-efficient.

Abstract: Fiber optic sensing systems and methods. In a described embodiment, a fiber optic sensing system includes an optical fiber transmitting energy to a chemical vapor deposited diamond material proximate a substance in a well. The diamond material is deposited as a coating on a substrate. The substrate and coating are heated when the energy is transmitted by the optical fiber. This heats the substance in the well, which is detected to determine a property of the substance. In another embodiment, light energy is transmitted through the diamond material.

Abstract: The present invention refers to an innovative construction introduced in an insulating system at the end of cables with electric-electronic sensors. The insulating system has a rubber plug that covers the end of the insulating cap of the sensor's supply cable. A metal cap is partially filled with epoxy resin (that covers the sensor in such a way that it sticks to the end of the rubber plug. The end of the cap is deformed to make a peripheral indentation against the rubber plug. The shape of the rubber plug has a proximal end of a diameter that is compatible with the internal diameter of the metal cap and a distal end of a larger diameter to create a support lift for the cap during the assembly. An optional construction for the rubber plug is a continuously cylindrical shape.

Abstract: A system and method for controlling a temperature indicator stick includes a housing having an interior configured to receive the temperature indicator stick configured to indicate a predetermined temperature through a physical change or a chemical when exposed to the predetermined temperature. A roller drive is supported by the housing to engage the temperature indicator stick. Accordingly, rotation of the drive roller causes a retraction or advancement of the temperature indicator stick to and from the interior of the housing. Additionally, the housing and temperature indicator stick may include a key system to keep the temperature indicator stick in a substantially fixed rotational position with respect to the housing as the temperature indicator stick advanced from and retracted into the housing.

Abstract: A spread-spectrum signal comprises a spreading waveform modulating a carrier wave and containing a real linear combination of a first waveform at a first waveform rate and a second waveform at a second waveform rate, the first waveform rate being distinct from the second waveform rate and both waveform rates being distinct and non-zero. The linear combination of the first and the second waveform is modulated with at least one binary sequence comprising a signal identification code.

Abstract: Remote control signaling may be conveyed using a spread spectrum link and/or a non-spread spectrum link. Enabling link interfaces (such as corresponding transmitters, receivers, or transceivers) to support this flexibility are provided in a shared housing and couple as appropriate to a remote control signal platform. A corresponding apparatus may comprise a housing having disposed therein a first radio frequency transmitter such as a spread spectrum transmitter and a second radio frequency transmitter such as a non-spread spectrum transmitter. This housing can further contain a remote control signal controller that operably couples to at least one of the first and second radio frequency transmitters. As another example, a corresponding apparatus may comprise a housing having disposed therein a first radio frequency receiver comprising a spread spectrum receiver and a second radio frequency receiver comprising a non-spread spectrum receiver.

Abstract: A transmitter configured for generating a frequency-hopped OFDM signal comprises a digital Fourier transform circuit, a variable bandpass filter, and a frequency-hopping controller. The digital Fourier transform circuit comprises a plurality of input frequency bins and is configured to modulate complex data symbols onto a plurality of OFDM subcarriers. The variable bandpass filter selects sets of the plurality of input frequency bins for frequency hopping the OFDM subcarriers over a plurality of subbands. The frequency-hopping controller controls the variable bandpass filter with respect to at least one predetermined frequency-hopping pattern.

Abstract: A differential orthogonal modulation method and a differential orthogonal modulation apparatus using a repetition time interval difference of a chirp signal are disclosed. Such a differential orthogonal modulation method performed in a transmitter unit of a digital communication system comprises the steps of converting data having a serial bit format to be transmitted in the transmitter unit into a parallel format to create parallel input data, inputting the parallel input data into a symbol mapper, orthogonally modulating the parallel input data inputted into the symbol mapper to create modulated data comprised of differential bi-orthogonal functions, differentially encoding the modulated data to output encoded data, converting the encoded data into a serial bit format to create a baseband signal, and processing the baseband signal to create a transmission signal in a form of a chirp signal having a specific repetition time interval difference.

Abstract: Techniques of channel correction and demodulation for orthogonal frequency division multiplexing (OFDM) systems are enhanced so that higher effective data rates and/or lower error rates can be achieved with a minimal processing load. Pilots are adaptively moved and/or removed, and their positions are changed, to enhance the channel estimation, decoding, and demodulation processes at the receiver. Reception is also enhanced by adding, removing, or changing the positions, of information-carrying data bits.

Abstract: A serial transmission system performs data transfer between a first port and a second port via a transmission path. The first port includes a receiving unit that receives data, a signal-quality measuring unit that measures the signal quality of receive data, a correction-request-data generating unit that generates correction request data for correcting output characteristics of the second port on the basis of a result of the measurement, and a sending unit that sends the generated correction request data. The second port includes a sending unit that sends data, a receiving unit that receives the correction request data from the first port, and a setting unit that changes settings of output characteristics of the sending unit on the basis of the received correction request data.

Abstract: In at least some embodiments, a receiver for a wireless communication system is provided. The receiver includes an equalizer that provides an equalized channel matrix. The receiver also includes scaling logic coupled to the equalizer, the scaling logic selectively scales coefficients of the equalized channel matrix. The receiver also includes a decoder coupled to the scaling logic. The decoder decodes a signal based on the equalized channel matrix with scaled coefficients.

Abstract: In a method for performing equalization of a communication system, a predetermined signal can be transmitted from a transmitter unit to a receiver unit in a downchannel direction on a transmission line, for example as a pair of differential signals which simultaneously transition in opposite directions on respective signal conductors of the transmission line. At the receiver unit, an eye opening of the signal received from the transmission line can be analyzed to determine equalization information. Equalization information can be transmitted from the receiver unit to the transmitter unit in an upchannel direction on the transmission line and be received at the transmitter unit. Using received equalization information, a transmission characteristic of the transmitter unit can be adjusted.

Abstract: Methods, apparatus and computer programs are provided for multiplication-free identification of the impulse response of an oversampled data channel. An input comprising a pseudo-random binary sequence of L symbols is supplied to the channel at a symbol rate of 1/T. A channel output is produced by sampling a channel output signal corresponding to the input with a sampling interval TS=(q/p)T, where q and p are relative prime integers with q<p, and q and L are relative prime integers. p polyphase sequences are produced from the channel output by selecting, for each polyphase sequence, every pth sample of the channel output, with a phase shift of one sample between successive polyphase sequences). A decimated binary sequence is produced by selecting every qth symbol of the channel input. Each polyphase sequence is correlated with the decimated binary sequence, the two possible binary values being of equal magnitude and opposite sign for the correlation.

Abstract: An equalization method and apparatus for a Time domain synchronous orthogonal frequency division multiplexing (TDS-OFDM) receiver. The equalization method includes estimating a channel impulse response (CIR) based on a baseband sampled complex signal and locally stored pseudo-noise; eliminating the pseudo-noise from the baseband sampled complex signal based on the CIR; computing channel information including first channel information and second channel information from the CIR; performing pre-fast Fourier transform (FFT) compensation of a pseudo-noise eliminated signal based on the first channel information; performing FFT of a pre-FFT compensated signal; and equalizing a fast Fourier transformed signal based on the second channel information.

Abstract: A data decoding method judges a signal state where there is a transition from a low level to a high level or from a high level to a low level at the center portion of a bit interval as logical “1” or “0”, and a signal state where a low level continues or a high level continues over the entire bit interval as logical “0” or “1”. The method has the steps of: measuring a first time duration in which the bit series signal transitions from a low level to the next low level, measuring a second time duration in which the bit series signal transitions from a high level to the next high level, and deciding a logical “0” or “1” value for the target bit to be decided based on the combination of the first time duration and the second time duration measured for the target bit.

Abstract: A system for displaying a first data signal and a second data signal is disclosed. The system includes: a decoder, for selectively decoding the first data stream to output a first decoded signal or the second data stream to output a second decoded signal according to a command signal; and a frame buffer, for receiving the first decoded signal or the second decoded signal to output a first video signal or a second video signal respectively; wherein when the decoder stops outputting the first decoded signal and starts outputting the second decoded signal, the frame buffer will buffer a last received frame of the first decoded signal, and when the decoder stops outputting the second decoded signal and starts outputting the first decoded signal, the frame buffer will buffer a last received frame of the second decoded signal.

Abstract: A real-time encoder, e.g., a real-time H.264 compliant encoder or a real-time AVC compliant encoder is disclosed. For example, the encoder comprises a first digital signal processor (DSP) for processing a first panel of an input image and a second digital signal processor (DSP) for processing a second panel of the input image. Finally, the encoder comprises a field programmable gate array (FPGA) for supporting both the first DSP and the second DSP.

Abstract: A basic pattern generating unit 81 generates a film grain basic pattern 86 in which the histogram of random noise is substantially the same as the film grain basic pattern information 53. The film grain basic pattern 86 is of (64×64) pixels and an area of (16×16) pixels is cut out and supplied to a multiplier 84. Strength information 88 is generated based on film grain strength information 54 produced on the encoding side and an average value 87 of a pixel value in the area of (16×16) pixels of decoded image information 42. The strength of basic pattern 86 is adjusted by this strength information 88. Film grain image 89 whose strength is adjusted is added to the area of (16×16) pixels of the decoded image information 42 by an adder 85 by the unit of pixel.

Abstract: When distributing a set 101 of frames 102 each with encoded data 103 from a transmitter 104 to a receiver 105, a dependent frame 108 requires an independent frame 107 for decoding, and the transmitting 111 of the frames 102 from a buffer 110 at the transmitter 104 is reordered such that the dependent frame 108 is sent after the independent frame 107. In particular, a transmission policy wherein buffering 109 a further frame 125 takes into account both: if the further frame 125 requires zero, one or two frames 102 of the set 101 for decoding, and the current frames 102 buffered at the first and the second position 123 of the transmit buffer 110.

Abstract: A storage medium having a data structure for seamlessly reproducing interactive graphic streams supporting multiple languages, and an apparatus and method therefor are provided. The storage medium includes: a main stream generated by compressing and encoding a multimedia image; and interactive graphic streams multiplexed into the main stream and forming a menu supporting a plurality of languages. The interactive graphic streams include page information on menu pages, and button information on buttons included in each menu page. Accordingly, a menu supporting a language selected by a user can be provided, and even when a switch operation between menus supporting a plurality of languages is performed, seamless reproduction is enabled.

Abstract: A system records an AV stream composed of a plurality of record units (RUs) containing independently reproducible video units (VUs) of at least video or audio and program information (Movie atom) managing the AV stream, onto a recording medium. The program information contains a piece of information (Edit list atom) that manages a point of junction between the record units or between AV streams. In decoding the AV stream, decoding is halted or decoders are switched at the point of junction, based on the management information on the points of junction, for example.

Abstract: The present invention makes it possible to include, when encoding processing is applied to three color components using a 4:0:0 format, data for one picture in one access unit and makes it possible to set the same time information or the same set encoding modes among the respective color components. In an image encoding system for applying compression processing to an input image signal including a plurality of color components, encoded data obtained by independently subjecting an input image signal of each of the color components to encoding processing and a parameter indicating which color component the encoded data corresponds to are multiplexed with a bit stream. In an image decoding system for inputting a bit stream in which an image signal including a plurality of color components is compressed to perform decoding processing, decoding processing of the encoded data of each of the color components is performed using a parameter indicating which color component the encoded data corresponds to.

Abstract: The present invention makes it possible to include, when encoding processing is applied to three color components using a 4:0:0 format, data for one picture in one access unit and makes it possible to set the same time information or the same set encoding modes among the respective color components. In an image encoding system for applying compression processing to an input image signal including a plurality of color components, encoded data obtained by independently subjecting an input image signal of each of the color components to encoding processing and a parameter indicating which color component the encoded data corresponds to are multiplexed with a bit stream. In an image decoding system for inputting a bit stream in which an image signal including a plurality of color components is compressed to perform decoding processing, decoding processing of the encoded data of each of the color components is performed using a parameter indicating which color component the encoded data corresponds to.

Abstract: The invention relates to a video data encoding device comprising means for encoding the images in data groups. The device comprises means for inserting, into the encoded data groups, a message comprising parameters representative of the chaptering of the data.

Abstract: In a video encoding method according to the present invention, an encoding mode controller 102 determines an encoding mode of each image on the occasion of encoding a moving picture consisting of a plurality of images, and a region partitioning unit 104 determines a region structural unit for partitioning the image into multiple regions, based on the encoding mode. A region determining unit 116 defines the regions on the basis of the region structural unit and information thereof is encoded. Then an encoder 105 compression-encodes pixel data included in the regions, in encoding units to generate compression-encoded data according to the encoding mode, and outputs the resultant data.

Abstract: A video sequence (4) is subjected to a signal compression process, in which the video sequence is divided (14) into a plurality of segments such that in each segment the number of bits required to code each frame in uncompressed form falls within a range having a predetermined magnitude, and a quantisation level is selected (17) for the encoding (19) of each segment such that the overall bit rate of the segment corresponds to a predetermined value. This value may be pre-set, or may be set in response to an input from the transmission network (3) or remote decoder (2). The quantisation level Q is determined according to a function of the number of bits per frame R, determined by analysis (10,11,12,13) of the entire sequence prior to transmission.

Abstract: There are provided apparatus and methods for parallelizing an encoding process across multiple processors. An apparatus includes a computing resource balancer and a splitter. The computing resource balancer is for assigning encoder instances to respective ones of the multiple processors based on at least one of thread affinity and process affinity. The splitter is for temporally dividing an incoming video sequence into discrete GOPs such that each of the encoder instances is capable of encoding the incoming video sequence in parallel so that each of the discrete GOPs is encoded on a respective one of the multiple processors.

Abstract: A method for line-based video rate control is provided. The line based video rate control method includes system feedback to change system operating parameters, including on a packet-by-packet basis and also on a line-by-line basis. Also provided is a method for line-based compression. The method includes basic elements of an arithmetic coder to improve Golomb coding performance. By inverting operations in the method for line-based compression, the corresponding decoder can be obtained. The method also provides a heuristic-driven method for generating prediction residuals from quantized data, wherein prediction is driven in the direction of maximum correlation so that it is unnecessary to supply the decoder with additional data specifying this direction at each array element.

Abstract: A method for line-based video rate control is provided. The line based video rate control method includes system feedback to change system operating parameters, including on a packet-by-packet basis and also on a line-by-line basis. Also provided is a method for line-based compression. The method includes basic elements of an arithmetic coder to improve Golomb coding performance. By inverting operations in the method for line-based compression, the corresponding decoder can be obtained. The method also provides a heuristic-driven method for generating prediction residuals from quantized data, wherein prediction is driven in the direction of maximum correlation so that it is unnecessary to supply the decoder with additional data specifying this direction at each array element.

Abstract: Method and apparatus for providing an estimate of the size of a compressed signal without actually compressing the signal. A compression estimation mechanism models the behavior of entropy encoders on the transform coefficients generated by the application of a discrete transform method on an input uncompressed signal. The compression estimation mechanism may be used to predict a lower bound and upper bound on the size of the compressed signal from the entropy encoders, or alternatively an estimated size of the compressed signal. Since embodiments use a model of the behavior of entropy encoders to predict the bounds of the compressed signal or the size of the compressed signal without performing the actual entropy encoding, the bounds or size estimate may be predicted in less time than it takes to perform full compression of the signal.

Abstract: The method is characterized in that, if the data relating to a first macroblock indicates that it is coded in frame prediction and field DCT mode, it comprises the following steps: determination of the second macroblock in the image which, with the first, forms a supermacroblock, each of the macroblocks having an associated MPEG2 inter-frame motion vector, V0 and V1, structuring of the macroblock in field mode and calculation of a partitioning of this supermacroblock according to the MPEG2 motion vectors V0 and V1, calculation of the motion vectors for each of the partitions according to the MPEG2 motion vectors V0 and V1.

Abstract: A method for receiving encoded H.264 video signals and transcoding the received encoded signals to encoded MPEG-2 video signals, including the following steps: decoding the encoded H.264 video signals to obtain uncompressed video signals and to also obtain H.264 feature signals; deriving MPEG-2 feature signals from the H.264 feature signals; and producing the encoded MPEG-2 video signals using the uncompressed video signals and the MPEG-2 feature signals. The H.264 feature signals include H.264 macro block modes and include H.264 motion vectors.

Abstract: A system and method for encoding a first picture sequence and a second picture sequence into coded pictures, with the first picture sequence and the second picture sequence being different, and with at least one coded picture of the second picture sequence being predicted from at least one picture in the first picture sequence. According to various embodiments of the present invention, signal element is encoded into a coded picture of the second picture sequence. The signal element indicates whether a picture in the first picture sequence is used for prediction of the coded picture of the second picture sequence.

Abstract: Provided is an intra-mode prediction search method for compression of a real-time video signal, the method including the steps of: measuring a Rate-Distortion (R-D) cost of a video-signal macro block received from outside; determining a search threshold value by comparing the R-D cost of the received macro block with R-D costs of neighboring macro blocks; determining an inter mode having the minimum sum of absolute error (SAE) by measuring the SAE of the received macro block for each inter mode; and determining an intra-mode prediction search in response to the minimum SAE of the determined inter mode and the search threshold value.

Abstract: An image encoder including: a predicted-image generating unit that generates a predicted image in accordance with a plurality of prediction modes indicating predicted-image generating methods; a prediction-mode judging unit that evaluates prediction efficiency of a predicted image outputted from the predicted-image generating unit to judge a predetermined prediction mode; and an encoding unit that subjects an output of the prediction-mode judging unit to variable-length encoding.

Abstract: A device capable of video data processing includes a first unit capable of analyzing at least one motion vector of a macroblock to determine at least one sub-region in at least one reference, each of the at least one sub-region corresponding to one of the at least one motion vector, a second unit capable of storing pixel data of each of the at least one sub-region, a third unit capable of storing an address of each of the at least one reference block, and a fourth unit capable of retrieving from a memory device compensation data corresponding to the address of each of the at least one reference block.

Abstract: A method of determining performance of block motion estimation procedures, including specific search patterns is disclosed. The patterns are based on genetic competition between paired coordinate points. An evaluation of a block matching cost is used to identify a survivor between the two selected points. Models are also provided for estimating performances of new search algorithms and image sequences.

Abstract: According to one embodiment, interpolated frame generating method of generating a new interpolated frame inserted between sequential frames, by using a plurality of input frame images, comprises first detecting of detecting at least one potential motion vector by block matching between the input frame images, using a first block of a fixed size, second detecting of detecting a motion vector by block matching between the input frame images, using a second block having a size variable within a range larger than that of the first block, and generating the interpolated frame by using the potential motion vector. The generating is generating the interpolated frame by using a potential motion vector closest to the motion vector detected by the second detecting among the potential motion vectors when a plurality of motion vectors are detected by the first detecting.

Abstract: A moving picture coding apparatus (10) for performing inter-picture predictive coding on pictures constituting a moving picture is provided with a coding unit (103) for performing predictive error coding on image data; a decoding unit (105) for performing predictive error decoding on an output from the coding unit (103); a reference picture memory (117) for holding output data from the decoding unit (105); and a motion vector detection unit (108) for detecting forward and backward motion vectors on the basis of decoded image data stored in the memory (117). When coding a B picture, a picture that is timewise closest to the target picture is used as a candidate picture for forward reference, and an I or P picture that is timewise closest to the target picture is used as a candidate picture for backward reference. The moving picture coding apparatus (10) so constructed can improve coding efficiency of a B picture to be subjected to bidirectional predictive coding.

Abstract: The disclosure details methods of measuring the quality of service of received media signals by analyzing digital watermarks embedded in such signals. The quality of a received video or audio signal can thereby be assessed without having the original version of the signal before transmission. Instead, the strength or quality of the embedded digital watermark is analyzed to determine the quality of the received signal. The degradation of a watermark signal is used to assess quality of service of signals, such as audio and video.

Abstract: A method of image processing for image conversion, comprises the steps of calculating a difference measure of the difference in pixel values between corresponding blocks of a current image field and a preceding image field, calculating a variability measure of the variability of pixel values from at least one of said corresponding blocks, determining whether the difference measure exceeds the variability measure, and if the difference measure exceeds the variability measure, then setting an inter-image mixing value for each pixel in the corresponding block of the current image field to indicate that the current image field should not be mixed with the preceding image field at that pixel position.

Abstract: Methods, medium, and machines which compress, enhance, encode, transmit, decode, decompress and display digital video images. Real time compression is achieved by sub-sampling each frame of a video signal, filtering the pixel values, and encoding. Real time transmission is achieved due to high levels of effective compression. Real time decompression is achieved by decoding and decompressing the encoded data to display high quality images. A receiver can alter various setting including, but not limited to, the format for the compression, image size, frame rate, brightness and contrast. In a Doppler improvement aspect of the invention, Doppler velocity scales are incorporated into grayscale compression methods using two bits. Variable formats may be selected and Doppler encoding can be turned on and off based on the image content.