Tektronix, Inc.

Project Giants, LLC

Other

Daniel G Baker

Scott E Zink

Michael S Overton

Barry A McKibben

Kenneth M Ainsworth

Michael D Nakamura

Evan Albright

Lakshmanan Gopishankar

Bruce J Penney

Gilbert A Hoffman

Robert W Parish

John J Horn

Magaret A Feisel

William J Cooper

Thomas L Tucker

George W Tusing

Brian R Walker

Michael Harris

A video format detector receives a video signal in a one of a plurality of possible video formats and produces a detected format. A cumulative distribution function generator generates a cumulative distribution function curve from a component of the video signal and a feature detector generates one or more feature vectors from the cumulative distribution function curve. A video classifier accepts the one or more feature vectors from the feature detector and generates a prediction of the video format in which the video signal was produced based, at least in part, on the received feature vectors.

High dynamic range video format detection

A video analyzer measures and outputs a visual indication of a dynamic range of a video signal. The video analyzer includes a video input to receive the video signal and a cumulative distribution function generator generates a cumulative distribution function curve from a component of the video signal. A feature detector generates one or more feature vectors from the cumulative distribution function curve and a video dynamic range generator produces a visual output indicating a luminance of one or more portions of the video signal.

Video dynamic range analysis

A waveform monitor for generating a modified image from an original image includes a measuring system to select luminance frequency values of the original image that are above a first and a second threshold. A modifier changes selected pixels of the original image that fall above the first and second thresholds. In some embodiments these changed pixels are given a false color as color markers to indicate DOF and areas of sharpest focus of the original image. Methods of modifying images in this manner are also described.

Depth of field indication using focus-peaking picture markers

A waveform monitor includes a brightness measuring system to generate brightness values that are then converted to stop equivalents. The conversion may be performed using a Look Up Table. The output is generated as a stop vs. time waveform. Methods of generating the stop vs. time waveform are also described.

Stop weighted waveform

A method for measuring a quality parameter, such as luminance uniformity, of a video display, according to some embodiments of the present invention, includes providing a plurality of pattern images to be displayed sequentially on the video display, measuring the amount of light produced by each pattern image using a wide-angle light sensor, and calculating the video display quality parameter using the measured light values corresponding to each displayed pattern. Each pattern used in accordance with this method is derived from an orthogonal matrix, resulting in each pattern having a high average brightness, thereby eliminating the need to use a narrow-angle, spot light meter, and instead allowing measurements to be made using a simple, wide-angle, incident-light or reflected-light photometer. This method is compliant with the relevant SMPTE measurement standard for measuring luminance uniformity. Additionally, some embodiments of the present invention provide an apparatus for practicing this method.

Apparatus and method to measure display quality

A stereoscopic video temporal frame offset measurement system uses an improved signature curve generator to generate a robust signature curve for each of the left and right image sequences of a stereo video signal. The resulting signature curves are cross-correlated over a specified correlation range to generate cross-correlation coefficients. The cross-correlation coefficients are compared to a high threshold, and a temporal frame offset is generated and displayed for each cross-correlation coefficient that exceeds the high threshold. Each new temporal frame offset result is highlighted when displayed, otherwise the last result is displayed in a background fashion.

Stereoscopic video temporal frame offset measurement

A waveform monitor for generating a modified image from an original image includes a brightness measuring system to generate brightness values that are then converted to f-stop equivalents. A selector is used to create a range of f-stop values and a modifier changes the original image for selected pixels that fall within the range of f-stop values. The original image may be modified by replacing or blending certain pixels with colorized pixels, i.e., by falsely coloring the original image. Methods of modifying images in this manner are also described.

F-stop weighted waveform with picture monitor markers

A method of generating a stereoscopic image registration and color balance evaluation display enables a user to align two cameras used to produce a stereoscopic video signal or to analyze a received stereoscopic video signal. Left and right images from the cameras are converted into desired video signal components. Corresponding pixels from the left and right images are compared for each of the video signal components, and plotted as x and y inputs to a Cartesian plot to produce respective two-dimensional (2D) histograms. The multiple 2D histograms are presented as a Quad Diamond display so a user may align the two cameras or analyze the received stereoscopic video signal.

Stereoscopic image registration and color balance evaluation display

Tiling or blockiness detection based on spectral power signature uses one-dimensional vectors at block edges to find a spectral signature created by the tiling or blockiness in an image. A baseband component of the image, such as luminance, is edge enhanced, and then the pixel values along each horizontal line are summed to form a one-dimensional column vector of summed edge values for the image. The power of the column vector and the power of selected frequency components within the column vector are determined. The powers are then combined and converted to dimensionless tiling or blockiness values relative to each of the selected frequencies.

Tiling or blockiness detection based on spectral power signature

Described are systems and methods of estimating a Signal-to-Noise (S/N) ratio of an input channel carrying a QAM signal. A Modulation Error Ratio (MER) is calculated for the input QAM signal, but uses only the centermost error values of a constellation of the input QAM signal in generating this modified MER. The modified MER accurately represents the S/N ratio of the input channel carrying the QAM signal. In this way the S/N ratio may be accurately determined using only the received I and Q components of the modulated QAM input signal itself.

Measuring channel signal to noise metric using constellation data

Embodiments of the present invention provide a 'disparity cursor' for easily measuring disparity within a selected region of a 3D image under test. In operation, a user places a window that defines the disparity cursor over a selected region of the 3D image under test using a mouse, keyboard, or other user-interface device. An average disparity value for the image segments contained within the window is then automatically calculated and reported to the user.

Semi-automatic 3D stereoscopic disparity cursor

A single-ended blur detection probe and method with a local sharpness map for analyzing a video image sequence uses two sets of edge filters, one for 'fast edges' and the other for 'slow edges.' Each set of edge filters includes a horizontal bandpass filter, a vertical bandpass filter and a pair of orthogonal diagonal filters where the frequency response of the fast edge filters overlap the frequency response of the slow edge filters. The video image sequence is input to each filter of each set, and the output absolute values are combined with weighting factors to produce a slow edge weighted sum array and a fast edge weighted sum arra. The respective weighted sum arrays are then decimated to produce a slow edge decimated array and a fast edge decimated array. The ratio of the maximum difference value between the decimated arrays and the maximum value from the fast edge decimated array, weighted by an appropriate factor, produces a localized maximum sharpness value, the log of which produces a dimensionless blur value.

Blur detection with local sharpness map

A test pattern for evaluating L/R crosstalk extinction ratio in a stereoscopic 3D system has a strip of one characteristic&#x2014;polarization, white, color&#x2014;associated with a plurality of calibrated chips in a left eye image and a strip of a contrasting characteristic&#x2014;orthogonal polarization, white, contrasting color&#x2014;associated with a plurality of calibrated chips in a right eye image such that, when the two images are superimposed, the strip of one image overlays the calibrated chips of the other image. By alternately occluding one eye while observing the superimposed image with the other eye, a portion of the strip of the occluded eye image appears across the chips of the viewing eye image when there is crosstalk. The extinction ratio value associated with the chip of the viewing eye image that most closely matches the portion of the strip from the occluded eye image is an estimate of the L/R crosstalk.

Stereoscopic extinction ratio test pattern

Embodiments of the present invention provide systems and methods for non-invasive, 'in-service' AV delay detection and correction. These systems and methods do not modify the audio signal or the video signal, nor do they rely on any metadata to be carried with the audio signal or the video signal via the distribution path. Instead, agents located at various points along the distribution path generate very small signature curves for the audio signal and the video signal and distribute them to a manager via a separate data path other than the distribution path. The manager calculates a measured AV delay caused by the distribution path based on these signature curves, and then optionally corrects the measured AV delay by adjusting an in-line delay in the distribution path.

AV delay measurement and correction via signature curves

A flexible timebase for eye diagrams uses a stable free running oscillator as a sample clock for equivalent time sampling of an input serial digital signal and of a reference signal, derived from a subdivided recovered clock of the input serial digital signal. The reference signal samples are provided to a digital phase-locked loop that provides the flexible timebase to an eye pattern generator. The eye pattern generator accumulates the input serial digital signal samples at times corresponding to the reference signal samples to produce the eye diagram. A linear phase detector in the digital phase locked loop converts the reference signal samples to a complex signal using a Hilbert transform and then to a linear ramp of phase values using a CORDIC algorithm with arctangent lookup table. A subtractor then subtracts the digital phase-locked loop feedback from the linear ramp to provide the input to the loop filter.

Growing community of inventors

Beaverton, OR, United States of America

Daniel G Baker