Abstract: An artistic color gamut display is generated by obtaining maximum and minimum values for an RGB signal. The maximum and minimum values are used as X and Y values for an XY plot. A triangular graticule, or Spearhead display, is generated for the XY plot having a first side representing Lightness, a second side representing saturation and a third side representing Value. The area within the Spearhead display represents valid color gamut. The Spearhead display may be combined with more traditional displays, such as Vector or Arrowhead displays, to provide a completely three-dimensional analysis of the RGB signal in terms of the artistic parameters of Hue, Saturation and Value or Lightness.

Abstract: A method of frequency response measurement for a sinusoidal test signal, such as a swept sinusoid signal, a multi-burst sinusoidal signal or the like, uses a complex sinusoid window at a particular frequency for correlation with the sinusoidal test signal. The resulting complex correlation magnitude signal is thresholded as a function of a percentage of a maximum complex correlation magnitude. A centroid of the thresholded complex correlation magnitude signal is found, and the complex correlation magnitude at the centroid is the frequency response at the particular frequency.

Abstract: A streaming media quality analyzer system compares original streaming media from a source, or original packetized streaming media from the source, with a reconstructed packetized streaming media representing the packetized streaming media as received over a network in a connectionless manner at a remote site. At the remote site the received packetized streaming media is analyzed to determine time of arrival of the packets including identification of missing packets. The analysis results are transmitted over the network to a measurement site and used to reconstruct the received packetized streaming media from the original packetized streaming media. The reconstructed packetized streaming media is then analyzed to determine the quality of the packetized streaming media received at the remote site.

Abstract: A first test signal from a test signal source is provided to a spectrum analyzer to produce first measurement data. The test signal source is expressed by a first transfer function G(w) and the spectrum analyzer is expressed by second transfer function F(w). A second test signal is provided to the spectrum analyzer to produce second measurement data where the second test signal is derived from the first test signal by shifting the frequency by a known increment. From the first and second measurement data, the components are the same on G(w) but different on F(w). The G(w) components are cancelled by calculation using the first and second measurement data and then the second transfer function F(w) is evaluated independently of G(w).

Abstract: Audio processing using a video rasterizer allows simultaneous display of both audio and video data on the same raster display. Audio samples are clocked into a buffer memory, such as a first-in, first-out (FIFO) buffer, by an audio clock and clocked out of the buffer memory by a rasterizer (system) clock to allow the audio data to cross over from the audio clock domain to the video clock domain. The audio data is then upsampled by a sample ratio converter/interpolator before being processed by a video display engine. The video display engine includes a polyphase filter for upsampling display data for input to a rasterizer from which the data is read for display.

Abstract: A jitter measurement method using a down-mixing or down-converting topology in a jitter measurement system preserves the jitter UI rather than the jitter seconds. An input serial data stream at a high baud is mixed with a stable local oscillator frequency that is close to that of the high baud. The difference between the high baud and the local oscillator frequency is passed by a filter as a lower rate serial stream. A clock recovery circuit recovers a lower rate clock from the lower rate serial stream, or an amplitude modulation removal stage converts the lower rate serial stream to a lower rate NRZ signal, or the lower rate serial signal is digitized. Jitter measurement is performed by a jitter measurement stage on the lower rate clock, the lower rate NRZ signal, or the digitized lower rate serial signal.

Abstract: A method and device for analyzing data, the sequence of which is describable by a state machine, has a configurable filter into which the data is input, an emulation of a part of the state machine implemented as a loadable hardware circuit in which states and conditions related to a current state are loaded, and means for determining a new current state from the states in the emulation resulting from applying the conditions to the filtered data. The configurable filter is reconfigured and the loadable hardware circuit is reloaded based upon the new current state being the current state. The process is continued until the data is processed according to the state machine.

Abstract: A high isolation RF switch for launching a selected one of two RF signals into a slabline transmission line structure has a three switch configuration—a pair of input switches coupled to corresponding input ports and a transition switch coupled to an output port via a slabline transmission line. The input switches select one of the input ports for coupling to the transition switch, and the transition switch couples the selected input port from the input switches to the output port. A grounded conductor is situated between the input ports in a cavity of a housing within which the high isolation RF switch is located to provide isolation between the input ports. Additional isolation between the input ports is provided by coupling the non-selected RF signal to ground, either by grounding the non-selected input to the transition switch or the non-selected input port.

Abstract: A method of generating reports for data in the form of a multiplicity of data files in an accessible data storage medium uses a user interface to specify a desired report and a sample data file name, the data file names having a variable portion and a non-variable portion. A search algorithm searches the accessible data storage medium for all related data files having the same non-variable portion in their data file names, and logically groups the data files according to the variable portion of their data file names. The related data files are processed according to specified parameters, such as thresholds and limits, and a display is provided of the analysis results, highlighting significant data. The report results with linked data may be stored on an intranet site in an appropriate format to be accessible via a web page using a conventional web browser.

Abstract: A high-speed digital-to-analog converter (DAC) measurement method acquires and quantizes an analog ramp output by the DAC corresponding to a digital ramp input to produce a quantized ramp, determines a start and end of the quantized ramp, obtains a difference between the quantized ramp and an ideal ramp to produce a quantized periodic signal (triangular or sinusoidal), determines a frequency for a qualified peak from an FFT of the quantized periodic signal, produces a mask filtered periodic signal from an iFFT around the qualified peak, and determines a sample window spanning a local maximum and minimum for each period of the quantized periodic signal. The ramp step levels are the averages of the samples within each sample window. From the step levels in DAC LSB's, resolution, monotonicity, differential lineary and integral linearity are determined for the DAC.

Abstract: A low phase noise YIG oscillator based phase locked loop couples an output frequency to a delay line discriminator to provide a phase noise feedback signal to a wideband tuning port of the YIG oscillator. A delay line in the delay line oscillator may be implemented with either a resonant circuit or a bandpass filter of sufficient bandwidth so that the output frequency and phase noise sidebands are not attenuated. The resonant circuit may be implemented as a YIG sphere integrated into the YIG oscillator in the same magnetic path as the YIG sphere in the oscillator circuitry.

Abstract: A surround sound display has a graphic sound stage image, including speakers representing sources and a central listener, and bent correlation meter scales for each stereo channel. The correlation meter scales have values from +1 at one end to ?1 at the other end and are bent to start from a central point along one side of the display between the speakers representing the stereo channels to a point along the opposing adjacent sides of the display outside the respective speakers. A marker, either in the form of individual pointers for each scale or as a fill area that spans the scales, indicates the correlation between the stereo channels. The thickness of the fill area indicates the amplitudes of the stereo channels.

Abstract: A two-dimensional video timing display with numeric readouts allows a user to quickly, easily and precisely measure the timing difference between video signals. A graphic display area within a raster display region provides a two-dimensional display of vertical timing offset and horizontal timing offset of an input video signal with respect to a reference video signal, the graphic display area including a reference indicator centered in the graphic area indicating the timing of the reference video signal and a timing indicator in the graphic area indicating the timing of the input video signal with respect to the reference video signal. A numeric display area is adjacent the graphic display area to display the actual vertical and horizontal timing offsets in appropriate units according to the format of the input video signal with a precision to one video clock cycle.

Abstract: An apparatus and method for predicting human vision perception and perceptual differences provides a perceptual difference model that merges two human vision systems, one for a reference video signal and the other for an impaired version of the reference video signal. The respective video signals are processed by spatio-temporal filters and, prior to differencing, by noise masking modules that apply a noise mask as a function of pupil size and luminance. The differenced filtered signal is an initial perceptual difference map to which other masking is applied to take into account correlation and contrast gain based upon the noise masks and filtered luminance from the spatio-temporal filters. The result is a more precise output perceptual difference map.

Abstract: A variable sample rate recursive digital filter is an adaptive digital filter where its coefficients are recalculated for each sample rate being processed in such a way as to maintain a constant frequency rate for all sample rates. An equivalent resampling is done by taking the ratio of the bilinear transforms at the respective sample rates. From an initial or calibrated sample rate and a corresponding initial filter coefficient, a new filter coefficient for a new sample rate is obtained by multiplying the initial filter coefficient by a constant or coefficient factor that is a function of the initial filter coefficient and a ratio of the initial and new sample rates: zFactor(z,R):=(1/z){(z(1+R)+(1?R))/(z(1?R)+(1+R))} The resulting new filter coefficient provides the adaptive digital filter with a constant frequency response when compared to the initial sample rate frequency response.

Abstract: A method of quantifying perceptual information and entropy for a data input signal uses an appropriate perceptual model to produce a perceptual response. The perceptual response is then entropy converted to produce the perceptual information and entropy. The entropy conversion may include the application of a transform function, such as a Karhunen-Loeve transform function, to the perceptual response to produce a set of coefficients, which coefficients then have probabilities calculated for them based on coefficient histograms of massive tests. The probabilities are used to calculate the perceptual information and entropy using standard techniques. The perceptual information and entropy may be used in applications for achieving greater accuracy subjective quality determinations for the data input signal.

Abstract: A method of measuring frequencies of multiple sinusoidal bursts in a signal uses a time-domain window that includes all the bursts which are then transformed to the frequency by domain an FFT. The magnitudes of the frequency bins are filtered and smoothed to create a minimum magnitude threshold array. An adaptive threshold is calculated from the minimum magnitude threshold array, maximum magnitudes of the frequency bins and an adjustable constant. The magnitudes are then compared to the adaptive threshold and the number of consecutive frequency bins above the adaptive threshold are counted and, if correct for the given signal, a centroid is determined for each frequency bin. If the number of bursts is not correct, then the adjustable constant is altered and the adaptive threshold recalculated. The centroids are converted to measured frequencies for the multiple sinusoidal bursts.

Abstract: A dither system for a quantizing device, such as a multi-stage pipelined analog-to-digital converter (ADC), derives a dither signal from a clock signal having a sample frequency, the dither signal having a frequency that is one-third of the sample frequency. The dither signal is easily converted to analog and added at the input of the quantizing device to an analog signal to be digitized. A cancellation signal circuit generates a cosine-wave signal from a digital version of the dither signal and programmable coefficients that are a function of amplitude and phase. The cosine-wave signal is combined with the digital output signal from the quantizing device to produce a corrected digital output signal having reduced quantization distortion.

Abstract: A fiber-pigtailed assembly for an optical detector with low back reflection and minimal polarization-dependent responsivity has a detector surface mounted adjacent a beveled end of a fiber pigtail such that the detector surface is tilted and rotated with respect to the beveled end of the fiber pigtail. Also an external optical fiber may be coupled to the fiber pigtail with low back reflection and minimal polarization-dependent responsivity by having an input ferrule at the end of the external optical fiber, the end being beveled; by having an intermediate ferrule at a coupling end of the fiber pigtail, the coupling end being beveled while the other end of the ferrule is beveled by the same amount but approximately orthogonal to the coupling end; and by having an output ferrule on the fiber pigtail adjacent to the intermediate ferrule, the end of the output ferrule adjacent to the intermediate ferrule being beveled.

Abstract: A method and device for finding a reference pattern in a serial stream of digital data draws up comparison tables for the front and rear bits of the reference pattern. Using the comparison table for the front bits, bits which in terms of time are located upstream of a point P in the data stream are compared, and using the comparison table for the rear bits, bits which in terms of time are located downstream of point P in the data stream are compared. Next, the number of bits matching the reference pattern upstream and downstream of the point P are added up, and in case the sum total is greater than or equal to the number of bits in the reference pattern, there is a signal that the reference pattern has been found.