Tektronix, Inc.

Bozidar Janko

Steven Douglas Maurer

Richard Guy Chambers

Douglas W Trobough

Peter M Compton

Paul A Cole

Aris Silzars

Myron A Bostwick, Jr

Wolfgang H Herr

Kevin M Ferguson

George M Williams

Shane Ching-Feng Hu

Kathryn A Engholm

Steven H Pepper

J Lynn Saunders

Valdis E Garuts

Frederick A Azinger

John W Edwards

Kenneth R Smith

Gale L Straney

William H Tomison

Bei Li

David K Fibush

Kenneth W Hawken

Kamalesh U Patel

Mark F Bitetto

Zoran O Sekulic

Scott K Diamond

John Raitz

Norman R Franzen

Justin F Whitling

Frederick Azinger

A system and method for automatic measurement of video parameters for a video sequence using a video processor that has a software waveform monitor implemented as an integral part of a video processing application run by the video processor. Each frame of the processed video sequence, either in realtime as processed by the video processor, in near realtime after storage by the video processor in a storage device, or in the background for each video sequence stored in the storage device, is analyzed against specified parameters for legalization and/or color balancing of the video sequence. The analysis results may be reported as a display in several forms&#x2014;an error image map, an error log, a timeline graphic, etc. The analysis results may also be provided to the video processor for automatic correction of the video sequence when the specified parameters are not satisfied.

Automatic measurement of video parameters

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.

Streaming media quality analyzer system

A picture quality measurement technique using blockiness provides realtime analysis without the use of a reference signal. A field/frame of an image represented by a processed video signal is captured in a bit-map for analysis. The image is filtered to enhance edges and then correlated with a kernel having a size corresponding to the block size of the compression algorithm used in compressing and decompressing the video signal to produce the processed video signal. The correlation results are processed by comparing an average value with the maximum value to produce a picture quality rating for the processed video signal.

Picture quality measurement using blockiness

A technique for image alignment with global translation and linear stretch determines translation parameters for three corresponding linearly displaced blocks in a reference image and a corresponding distorted test image. From the differences between the translation parameters for the three blocks the presence of stretch is detected and, if detected, a stretch factor is estimated. The estimated stretch factor is used as a starting point to stretch the reference image to overlap the distorted test image as a refinement process. The resulting refined stretch factor is then used in a reverse stretch process to shrink the distorted test image, and the distorted test image is then aligned with the reference image to obtain picture quality metrics.

Image alignment with global translation and linear stretch

A method of determining the blockiness period in DCT-based codecs determines the blockiness period having the maximum measurement value for each image of an input video signal. The blockiness periods having the maximum measurement values for each image are accumulated in a histogram representing the number of images at each different blockiness period. The maximum peak of the histogram represents the blockiness period induced by DCT-based codecs.

Blockiness period detection of DCT-based codecs

A method of detecting frozen fields in a video signal that has undergone analog encoding at some point along a transmission path acquires the video signal as a digital video signal. Every field of the digital video signal and its nth subsequent field are selected as a pair, where n is an integer multiple of the number of fields required for one cycle of color phasing in the analog encoding. The pairs of the selected fields are compared and, if the difference is essentially zero, a frozen field error is indicated.

Frozen field detection of formerly encoded video

A method of measuring blockiness in a video signal generates a power spectrum for a video field of the video signal. The largest peaks of the power spectrum at the higher frequency end of the power spectrum are initially selected and a common frequency interval between peaks is determined. The contribution to the amplitude of peaks at the common frequency interval by peaks at other than the common frequency interval are subtracted from the amplitude of the peaks at the common frequency interval. The average of the corrected amplitudes of the peaks at the common frequency interval is obtained and normalized as a blockiness metric for the video signal.

Harmonic measurement of blockiness in video signals

A method and apparatus for the detection of Gaussian noise in a video signal decomposes an image from the video signal to obtain best qualified blocks having a relatively uniform luminance. From the best qualified blocks an average standard deviation is calculated, and then smoothed by temporal filtering. The filtered average standard deviation is finally calibrated against a scale of corresponding input noise levels to obtain the Gaussian noise in the video signal.

Detection of Gaussian noise in video signals

An apparatus and method for the detection of repeated and frozen frames in a video signal obtains the absolute differences between pixels in corresponding fields of consecutive frames and generates a logic bit-map based on a threshold that is related to a maximum absolute difference for the field. The logic &ldquo;1&rdquo;s in the logic bit-map are counted to determine a normalized distribution count for the field and to determine an actual count in each of a plurality of segments of the logic bit-map. The actual counts are compared with bounds generated from the normalized distribution count and, if all the actual counts for the field are within the bounds, a repeated frame is reported. Alternatively in the absence of noise the actual counts are compared with a minimum value and, if all of the actual counts are below the minimum value, a repeated frame is reported.

Detection of repeated and frozen frames in a video signal

In a system for measuring the quality of a received video sequence with respect to an original video sequence a low duty-cycle transport of video reference images from the original video sequence is used to transmit full quality images. Such a reference frame from the original video sequence is selected and transmitted as a full quality video image, either separately or as part of the transmission of the original video sequence after processing. The processed original video sequence becomes a received video sequence at a receiver, and the frame corresponding to the reference frame is extracted and compared with the full quality received reference frame to obtain a measure of the quality of the received video sequence.

Low duty-cycle transport of video reference images

Attentional maps that reflect the subjective view of an observer to the effects of degradation in a video image are used in the objective measurement of video quality degradation. The observer assists in generating an attentional map for each image of a test image sequence, which provides different thresholds or weighting factors for different areas of each image. A video image sequence from a system under test is compared with the test image sequence, and the error results are displayed as a function of the corresponding attentional maps.

Attentional maps in objective measurement of video quality degradation

A method of automatic measurement of compressed video quality superimposes special markings in the active video region of a subset of contiguous frames within a test video sequence. The special markings provide a temporal reference, a spatial reference, a gain/level reference, a measurement code, a test sequence identifier and/or a prior measurement value. The temporal reference is used by a programmable instrument to extract a processed frame from the test video sequence after compression encoding-decoding which is temporally aligned with a reference frame from the test video sequence. The spatial reference is used by the programmable instrument to spatially align the processed frame to the reference frame. The measurement code is used by the programmable instrument to select the appropriate measurement protocol from among a plurality of measurement protocols. In this way video quality measures for a compression encoding-decoding system are determined automatically as a function of the special markings within the test video sequence.

Programmable instrument for automatic measurement of compressed video

An inverse scattering processing method with enhanced noise immunity and resolution capabilities for use in modeling multi-layer acoustic, electromagnetic or other propagating media. A time bounded filtering step is incorporated within a peeling method for use in processing TDR characteristic waveforms of the propagating media.

Reduced noise sensitivity in inverse scattering through filtering

A probe for testing integrated circuits includes a stiff elastic substrate including a conductive plane, the substrate having a major portion with fingers projecting therefrom in cantilever fashion. A layer of dielectric material is adhered to the substrate and has a main surface remote from the substrate. A plurality of conductor runs are adhered to the layer of dielectric material at the main surface thereof. The conductor runs extend over at least some of the fingers and are configured to form transmission lines when the conductive plane is connected to a reference potential level.

Probe with microstrip transmission lines

A test fixture for a high pin count surface mounted IC device has a test head assembly connected to an adapter having electrically conductive elements that couple the output of the IC device to test points on the test head assembly. The test points are coupled to conductive pads on the test head assembly via conductive runs. The test head assembly conductive pads mate with conductive pad formed in the electrically conductive elements of the adapter. The conductive elements engage leads on the IC device providing conductive paths between the IC leads an the test points on the test head assembly. The test fixture is secured to the IC device by friction forces between the periphery of the IC device and the inner surface of the adapter. The test fixture or the adapter is usable as a low profile chip carrier by inverting the fixture or adapter and as a circuit board interconnect.

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Portland, OR, United States of America

Bozidar Janko