PQASW Picture Quality Analyzer Datasheet
Contents
1. CODEC design optimization and verification Conformance testing transmission equipment and system evaluation Digital video mastering Video compression services Digital consumer product development and manufacturing Picture quality analysis software The PQASW PQA is the Picture Quality Analysis Software based on the concepts of the human vision system which provides a suite of repeatable objective quality measurements that closely correspond with subjective human visual assessment These measurements provide valuable information to engineers working to optimize video compression and recovery and maintaining a level of common carrier and distribution transmission service to clients and viewers Compressed video requires new test methods The true measure of any television system is viewer satisfaction While the quality of analog and full bandwidth digital video can be characterized indirectly by measuring the distortions of static test signals compressed television systems pose a far more difficult challenge Picture quality in a compressed system can change dynamically based on a combination of data rate picture complexity and the encoding algorithm employed The Static nature of test signals does not provide true characterization of picture quality Human viewer testing has been traditionally conducted as described in ITU R Rec BT 500 11 A test scene with natural content and motion is displayed in a tightly con2. HD display and viewing measurement class 12 www tektronix com 003 CIF and QVGA PQR measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection CIF QVGA LCD 7 scrn heights NA Typical NA Default PQR Units 20 cd m weightings 004 D CINEMA PQR measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection DMD Projector 3 scrn heights NA Typical NA Default PQR Units 1 cd m weightings 005 SD Broadcast DMOS measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection SD Broadcast ITU R BT 500 NA Typical NA Default DMOS Units Re CRT weightings BT 500 Training 006 HD Broadcast DMOS measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection HD Broadcast ITU R BT 500 NA Typical NA Default DMOS Units Re CRT weightings BT 500 Training 007 CIF and QVGA DMOS measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection CIF QVGA LCD 7 scrn heights NA Typical NA Default DMOS Units Re 20 cd m weightings BT 500 Training 008 D CINEMA DM
3. Spatial Gradient Artifacts Enable Weighting E 100 amp LostEdges Blurring E 100 Added Edges Ringing E 100 amp Rotated Edges Blocking _ Produce complimentary data OR DC Blockiness Artifacts Enable Weighting E 100 DC Blockiness Overall Artifact Weighting 0 o U Artifact detection settings For example artifact detection can help answer questions such as Will the DMOS be improved with more de blocking filtering or Should less prefiltering be used If edge blocking weighted DMOS is much greater than blurring weighted DMOS the edge blocking is the dominant artifact and perhaps more de blocking filtering should be considered In some applications it may be known that added edges such as ringing and mosquito noise are more objectionable than the other artifacts These weightings can be customized by the user and configured for the application to reflect this viewer preference thus improving DMOS prediction www tektronix com 5 PQASW Datasheet Likewise PSNR can be measured with these artifact weightings to determine how much of the error contributing to the PSNR measurement comes from each artifact The Attention Model and Artifact Detection can also be used in conjunction with any combination of picture quality measurements This allows for example evaluation of how much of a particular noticeable artifact will be seen where a viewer is most likely to look Comp
4. defined measurement from the Configure Measure dialog menu 6 www tektronix com Measure Measures 000 View Video 001 SD Broadcast POR 002 HD Broadcast POR 003 CIF and QVGA FOR 004 D CINEMA PGR HU 005 SD Broadcast DMOS spent 006 HD Broadcast DMOS m 007 CIF and QVGA DMOS Single Ended 008 D CINEMA DMOS Dual Ende 009 SD Broadcast ADMOS icc Measure Description Attention Weighted Difference Mean Opinion Score ADMOS Prediction Simulated displays amp human vision system at a BT 500 viewing conditions Generally best prediction accuracy but slower Reference Show Import Export Setting Import from script Export to script C Wiews Savannah Branch_otiwari goldeneye sr Enter the name of the file to be saved If the file does not exist a new file will be created Apply Process Workflow Cima gt rri Perceptual Samar Model odel Difference Node eg i i RET Mr nud ho eu RENT d Name Copy 2 of 006 HD Broadcast DMOS Description Perceptual Difference Map amp DMOS Prediction Simulated BT 500 interlaced CRT displays amp typical viewer s humar Edit measure dialog PQASW Datasheet Easy to use interface File View Configure Execute Help hon The PQA has two modes Measurement and Review The Measurement ee ee mma ca d Prek gt mode is used to execute the measurement selected in the Configure Dialog During measurement execution the summary data and map
5. 56 04 50 90 Middle East Asia and North Africa 41 52 675 3777 The Netherlands 00800 2255 4835 Norway 800 16098 People s Republic of China 400 820 5835 Poland 41 52 675 3777 Portugal 80 08 12370 Republic of Korea 001 800 8255 2835 Russia amp CIS 7 495 6647564 South Africa 41 52 675 3777 Spain 00800 2255 4835 Sweden 00800 2255 4835 Switzerland 00800 2255 4835 Taiwan 886 2 2722 9622 United Kingdom amp Ireland 00800 2255 4835 USA 1 800 833 9200 European toll free number If not accessible call 41 52 675 3777 Updated 10 April 2013 For Further Information Tektronix maintains a comprehensive constantly expanding collection of application notes technical briefs and other resources to help engineers working on the cutting edge of technology Please visit www tektronix com Copyright Tektronix Inc All rights reserved Tektronix products are covered by U S and foreign patents issued and pending Information in this publication supersedes that in all previously published material Specification and EX price change privileges reserved TEKTRONIX and TEK are registered trademarks of Tektronix Inc All other trade names referenced are the service marks trademarks or registered trademarks of their respective companies ey 03 Jul 2014 28W 26738 7 www tektronix com Tektronix S
6. GXF AVI LXF H263 X X X X X MP2 X X X X X X X X X MP4 X X X X X X H264 AVC X X X X X X X X DV X X X X X X VC 1 X X X ProRes X Quicktime X JPEG2000 X X X X X VC3 X X X X X DNxHD Raw X X X Preconfigured measurements set Some measurements are available only with Option ADV View video with no measurement Requires Option BAS class Measurement name 000 View Video No applicaable configuration nodes Subjective prediction Full reference Noticeable differences SD display and viewing 001 SD Broadcast PQR measurement measurement class Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection SD Broadcast ITU R BT 500 NA Typical NA Default PQR Units CRT weightings HD display and viewing 002 HD Broadcast PQR measurement measurement class Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection HD Broadcast ITU R BT 500 NA Typical NA Default PQR Units CRT weightings www tektronix com 11 PQASW Datasheet CIF display and viewing measurement class D CINEMA Projector and viewing measurement class Subjective rating predictions SD display and viewing measurement class HD display and viewing measurement class CIF display and viewing measurement class D CINEMA Projector and viewing measurement class Attention biased subjective rating predictions SD display and viewing measurement class
7. UDP IGMP support IGMP support in IP capture will make stream selection simple at multicast streaming The compressed video file captured through IP will be converted to an uncompressed file by an internal embedded decoder Embedded sample video files The user can run the measurement with the embedded sample video file when the software is invoked without valid option key code or dongle Jogger video file Supported file formats for measurement All formats support 8 bit unless otherwise stated a yuv UYVY YUY2 YUV4 4 4 YUV 4 2 0 planar 8 10 bit m Vv210 10 bit UYVY 3 components in 32 bits gb BGR24 GBR24 Avenue video file Video Description Jogger Reference 320x180 1 mb s 2 mb s Avenue Reference 320x180 1 mb s 2 mb s avi uncompressed BGR32 discard alpha channel BGR24 UYVY YUY2 v210 ARIB ITE format 4 2 0 planar with 3 separate files yyy vcap created by PQA600A or PQA600B SDI video capture vcap10 10 bit created by PQA600A or PQA600B video capture 10 www tektronix com PQASW Datasheet The following compressed files are internally converted to an uncompressed file before measurement execution The format support listed here is available in software version 4 0 and later Format ES ADF MP4 3GPP Quicktime MP2 PES MP2PS MP2 TS MXF
8. not see Attention model The PQASW also incorporates an attention model that predicts focus of attention this model considers Motion of objects Skin coloration to identify people Location Contrast Shape Size Viewer distraction due to noticeable quality artifacts Attention map example the jogger is highlighted These attention parameters can be customized to give greater or less importance to each characteristic This allows each measurement using an attention model to be user configurable The model is especially useful to evaluate the video process tuned to the specific application For example if the content is sports programming the viewer is expected to have higher attention in limited regional areas of the scene Highlighted areas within the attention image map will show the areas of the image drawing the eye s attention PQASW Datasheet Artifact detection Artifact detection reports a variety of different changes to the edges of the image Loss of edges or blurring Addition of edges or Ringing Mosquito noise Rotation of edges to vertical and horizontal or edge blockiness Loss of edges within an image block or DC blockiness They work as weighting parameters for subjective and objective measurements with any combination The results of these different measurement combinations can help to improve picture quality through the system dh ACE gas A rime ur Artit VEN a Je
9. MOS with PSNR In the examples Reference E is a scene from one of the VClips library files The image Test F has been passed through a compression system which has degraded the resultant image In this case the background of the jogger in Test F is blurred compared to the Reference image E s Wt E Reference A PSNR measurement is made on the PQA of the difference between the Reference and Test clip The highlighted white areas of PSNR Map C shows the areas of greatest difference between the original and degraded image Another measurement is then made by the PQA this time using the Predicted DMOS algorithm and the resultant Perceptual Difference Map for DMOS H image is shown Whiter regions in this Perceptual Contrast Difference map indicate greater perceptual contrast differences between the reference and test images In creating the Perceptual Contrast Difference map the PQA uses a human vision system model to determine the differences a viewer would perceive when watching the video G PSNR map H Perceptual difference map for DMOS 4 www tektronix com The Predicted DMOS measurement uses the Perceptual Contrast Difference Map H to measure picture quality This DMOS measurement would correctly recognize the viewers perceive the jogger as less degraded than the trees in the background The PSNR measurement uses the difference map G and would incorrectly include differences that viewers do
10. OS measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection DMD Projector 3 scrn heights NA Typical NA Default DMOS Units Re 1 cd m weightings BT 500 Training Requires Option ADV 009 SD broadcast ADMOS measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection SD Broadcast ITU R BT 500 NA Typical NA Default DMOS Units Re CRT weightings BT 500 Training 010 HD Broadcast ADMOS measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection HD Broadcast ITU R BT 500 NA Typical NA Default DMOS Units Re CRT weightings BT 500 Training CIF display and viewing measurement class SD sports measurement class HD sports measurement class SD talking head measurement class Repurposing reference and test are independent Format conversion cinema to SD DVD measurement class Format conversion SD to CIF measurement class Format conversion HD to SD measurement class 011 CIF and QVGA ADMOS measurement PQASW Datasheet Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection CIF QVGA LCD 7 scrn heights NA Typical NA Default DMOS Units Re 20 cd m weighting
11. R dB measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection NA Auto align Selected NA NA NA dB units Spatial Artifact measurement Requires Option ADV Removed edges measurement 021 Removed Edges Percent measurement class Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection NA Auto align NA NA Blurring NA spatial Added edges measurement 022 Added Edges Percent measurement class Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection NA Auto align NA NA Ringing NA spatial Mosquito Noise 14 www tektronix com Rotated edges measurement class of original deviation from block DC measurement class Artifact classified filtered PSNR Removed edges measurement class Added edges measurement class Rotated edges measurement class of original deviation from block DC measurement class Artifact annoyance weighted filtered PSNR PSNR w default artifact annoyance weights measurement class 023 Rotated Edges Percent measurement PQASW Datasheet Display model View model PSNR Perceptual Artifact Attention model Summary no
12. Rate 29 97 Structure progressiw Format YCbYCr4 Width 14 Reference Start 1 End 100 15 Impaired F Start 1 End 100 16 17 Decoder Reference Status Enabled Decoder T YUV Frame Cot 100 Multiplier 1 Input SpatiLeft px 0 Right px 0 Top px 0 Bottom p c Cc Uu WwWN 1920 Height 1920 Height Impaired Status Enabled Decoder T YUV Frame Cot 100 Multiplier 1 Input SpatiLeft px 0 Right px 0 Top px 0 Bottom p 92 93 Frame Min Max 94 Mean Abs StdDev Minkowski DMOS POR PSNR 95 10 10 1 0 12953 0202653 0003494 0004873 0 00597 0021996 96 820 202 061641 0 971552 0 006144 0010455 0 01574 0 152398 97 830 303 207411 4739135 0 009329 0 025023 0047669 1355691 98 4 0 lt 404 2 17319 4332368 0 026574 0 065872 0 097053 5 13395 99 8 50 505 1 89604 2 648358 0058101 0 11367 0 153323 12 53955 100 6 0 lt 6 06 165166 206427 0 070152 0 124533 0 164091 14 36769 M 4 hi 006 HD Broadcast DMOS Ready Result file sample PQASW Datasheet IP interface The IP interface enables both generation and capture of compressed video with two modes of simultaneous operation Channel 2 Mode IP Capture v CD 0 Avalable Disk Space 13145 MB Packets Recorded Channel 1 Mode IP Generate Y _rcorfigsettngs CHa IP Gock settings _ Cephure To Browse Test2 trp Generation capture Simultaneous generation and capture lets the user playout the reference video clips direct
13. Tektronix E Picture Quality Analysis Software PQASW Datasheet The PQASW is the picture quality analysis software based on the concepts of the human vision system which provides a suite of repeatable objective quality measurements that closely correspond with subjective human visual assessment Key features Fast accurate repeatable and objective picture quality measurement Predicts DMOS Differential mean opinion score based on human vision system model P interface with simultaneous Generation Capture and 2 Ch capture Option IP Picture quality measurements can be made on a variety of UHDTV1 4K formats 3840x2160 4096x2160 HD video formats 1080p 1080i 720p and SD video formats 525i or 6251 User configurable viewing condition and display models for reference and comparison Option ADV Attention Artifact weighted measurement Option ADV Region of interest ROI on measurement execution and review Automatic temporal and spatial alignment Embedded reference decoder Easy regression testing and automation using XML scripting Option ADV with Export Import file from GUI Multiple results view options Embedded sample reference and test sequences Wide variety of file format support including YUV 4 2 0 planar 10 bit which is in the uncompressed file generated by the Tektronix MTS4EAV7 analyzer when decoding a HEVC Main 10 profile stream Installs on your own PC Applications
14. ceptual Contrast Objective Mean Abs LSB dB Map type Signed on gray or unsigned on black Worst case Training Sequence for ITU R BT 500 Training Default or User application Tuned Determined by Worst Case Video Perceptual Contrast Error Log Threshold Save Mode Ordering information Models PQASW PQASWUP PC requirements Operating system Processor Display RAM Hard disk drive Application Data Included accessories PQASW documentation 071 3280 xx 071 3281 xx 077 0985 xx 077 0987 xx Other accessories 020 3145 xx Picture Quality Analysis software Field upgrade kit for the PQASW Windows 7 64 bit Dual core or more 1024x768 or higher resolution 4 GB or greater 1 GB minimum 50 GB or more recommended User manual Measurement technical reference Quick start user manual Russian Release notes Application install disk with instructions Software key dongle 2 These PDF only documents are available on the Tektronix Web site www tektronix com manuals 18 www tektronix com Options PQASW options ADV Advanced measurement package script execution user configurable measurement artifact attention weighting measurement IP IP Generation Capture USB USB dongle PPD Parallel port dongle LUD Add permissions to an existing dongle PQASWUP options ADV Advanced measurement package script execution user configurable measurement artifact attention weighting measurement IP IP Generation Capture Pr
15. d m and BT 500 Training ITU R BT 500 017 SD from HD Broadcast DMOS measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection SD and HD ITU R BT 500 NA Expert NA NA DMOS Units Re Broadcast CRT BT 500 Training www tektronix com 13 PQASW Datasheet Format conversion SD to HD 017 A SD from HD Broadcast DMOS measurement measurement class Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection SD and HD ITU R BT 500 NA Expert NA NA DMOS Units Re Progressive CRT BT 500 Training Format conversion CIF to 018 QCIF from CIF and QVGA DMOS measurement QCIF measurement class Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection QCIF and CIF 7 scrn heights NA Expert NA NA DMOS Units Re QVGA LCD 20 cd m BT 500 Training Attention Attention measurement class 019 Stand alone Attention Model measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection NA NA NA NA NA Default Map units weightings Probability of focus of attention Objective measurements Full reference General difference PSNR measurement class 020 PSN
16. dB units Spatial selected Requires Option ADV 034 Attention Weighted PSNR dB measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection NA NA Selected NA NA Default dB units weightings Objective measurements No reference Artifact Artifact measurement class Requires Option ADV 035 No Reference DC Blockiness Percent measurement PQASW Datasheet Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection NA NA NA NA No reference DC NA DC blockiness block Subjective prediction calibrated by Conducted in 2009 with 1080i29 Video Contents and H 264 CODEC Refer to application note 28W_24876_0 pdf subjective rating 036 HD PQR ITU BT500 with Interlaced CRT measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection Custom HD CRT 3 scrn heights NA Custom NA NA PQR units 037 HD DMOS ITU BT500 with Interlaced CRT measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection Custom HD CRT 3 scrn heights NA Custom NA NA DMOS Units Re BT 900 Training 038 HD ADMOS ITU BT500 with Interlaced CRT measurement Display model View model PSNR Perceptual Artifact Attention model Summar
17. de difference detection NA Auto align NA NA Edge Blockiness NA Spatial 024 DC Blocking Percent measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection NA Auto align NA NA DC Blockiness NA Spatial Requires Option ADV 025 Removed Edges Weighted PSNR dB measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection NA Auto align Selected NA Blurring NA dB units Spatial 026 Added Edges Weighted PSNR dB measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection NA Auto align Selected NA Ringing NA dB units spatial Mosquito Noise 027 Rotated Edges Weighted PSNR dB measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection NA Auto align Selected NA Edge Blockiness NA dB units spatial 028 DC Blocking Weighted PSNR dB measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection NA Auto align Selected NA DC Blockiness NA dB units spatial Requires Option ADV 029 Artifact Annoyance Weighted PSNR dB measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection NA Auto align Selected NA All artifacts NA dB units spatial selected www tektronix com 15 PQASW Datasheet Repurp
18. i o OUt put ROIBOttOme a refinputROILeft O refInputROIRight 0 refinputROITOop 0 refInputROIBottome 0 impInputROILeft O NGLODET no dRTONEe 0 autoRefHor izcrop true autoRefvertcrop true autoImpHor izcrop wr autoImpvertCrop true autoImpHorizsShift true auto autoTemporalAlign true minSearchDelay 1 maxSearchDelay 1 lt blocki gt Script sample Show Import Export Setting Import From script F video MeasureSetting xml Export to script F video MeasureSetting xml Enter the name of the File to be saved IF the file does not exist a new file will be created Import Export script in configure measure dialog om Home d y 1 aa N r5 aoe ool jd mi JE Open Quick Print Copy Find Go Page Print Switch int Preview To Setup Area Windows Office Document Edit Page Setup Window OR TT lt P EUN NITRATE WY UN YW AT OY NY PT VT Y PQA Versi 3 Tektroni 006 HD Broadcast DMOS Perceptual Difference Map amp DMOS Prediction Simulated BT 500 interlaced CRT displays amp typical viewers human vision system at a viewing distance Measure N LuminanceOnly Summary Min 0 Max 100 Units Reference nits Impaired Ir nits Result Maj perceptual contrast Command Parameters Measure T Dual Only 10 Reference CAVideoVAEU testiDriing ref 420 8b tt 1920x1088 yuv 11 Rate 29 97 Structure progressi Format YCbYCr4 2 Width 12 Impaired C AVideowAEU testiDrang test 420 Bbit_ 1920x1088 yuv 13
19. ied for picture quality through various conversion processes Prediction of human vision perception PQA measurements are developed from the human vision system model and additional algorithms have been added to improve upon the model used in the PQA200 300 This new extended technology allows legacy PQR measurements for SD while enabling predictions of subjective quality rating of video for a variety of video formats HD SD CIF etc It takes into consideration different display types used to view the video for example interlaced or progressive and CRT or LCD and different viewing conditions for example room lighting and viewing distance p gun Cognitive Task Input E Vision i based Format Display View Perceptual Attention Summary M Conversion Model Mode P Model P Model Measures 4 aA A Test Results Input s Format Display View Picture quality analysis system A model of the human vision system has been developed to predict the response to light stimulus with respect to the following parameters Contrast including supra threshold Mean luminance Spatial frequency Temporal frequency Angular extent Temporal extent Surround Eccentricity Orientation Adaptation effects M A AU LII a mmm a A ssi D rd e LL h i NENNEN dl A HHHH HHH F 0 1 100 A Modulation sensitivity vs temporal frequency PQASW Da
20. ing with XML scripting In the CODEC debugging optimizing process the designer may want to repeat several measurement routines as CODEC parameters are revised Automated regression testing using XML scripting can ease the restrictions of manual operation by allowing the user to write a series of measurement sequences within an XML script The script file can be exported from or imported to the measurement configuration menu to create and manage the script files easily Measurement results of the script operation can be viewed by using either the PQA user interface or any spreadsheet application that can read the created csv file format as a summary Multiple scripts can be executed simultaneously for faster measurement results File Edit Format View Help lt blockl gt MEASURE name 020 PSNR dB startRefFramee 1 ndRef Fr ames 80 startiImpFramee 1 endImpFramee 80 dualended true reference C Video AEU_test Stall ref 420 8bit 1920x1088 yuv refwidth 1920 FefHeight 1088 refRate 29 97 refInterlace refLeftcrop 1 000000 a aves 1 000000 ref Topcrop 1 000000 iach aids el Le 000000 impairede C videoXAEU test impHor iz5cale 100 000000 impHor izShift 0 000000 all test 420 Sbit 1920x1088 yuv impwidth 1920 impHeight 1088 impRate 29 97 impInterlace impvertScale 100 000000 a4 anid 0 000000 impt eftcrop 1 000000 MOI y iu OUTPUTROTENCFr ames 80 outputROI Left o OUTPUTROIRIght 0 outpu iL d
21. is used when running measurements for reference and test videos which have different aspect ratios Input Temporal ROI also known as temporal sync is used to execute measurements just for selected frames and minimize the measurement execution time 8 www tektronix com Fie View Configure Execute Help View GV test 420 Sbit 1320 1060 020 f Uritz A n Measure Ger esi Ee F e Qada g b ib b eme PSDI Out frame 1 0 of 100 0 J Dutput Spatial RO ni rona 2 ae M M Congue Update Graphs 8 TK a T Ra ra GV _test 420 Ebit 1920x1080 020 PSNR dB C Wideo AEU testGV test 420 Bbit 19201080 Results 020 PSNR dB csv ruts Mare 40 576 Max 41 087 Overalt 40 921 Output spatial ROI on review mode for in depth investigation Output ROIs can be used to review precalculated measurement results for only a subregion or temporal duration Output Spatial ROI is instantly selected by mouse operation and gives a score for just the selected spatial area Its an effective way to investigate a specific spatial region in the difference map for certain impairments Output Temporal ROI is set by marker operation on the graph and allows users to get a result for just a particular scene when the video stream has multiple scenes It also allows users to provide a result without any influence from initial transients in the human vision model Each parameter can be embedded in a measurement for the recursive operation Automated test
22. ly from an IP port in the PC into the device under test The test output from the device can then be simultaneously captured by the PC This saves the user from having to use an external video source to apply any required video input to the device under test With this generation capability files created by video editing software can be directly used as reference and test sequences for picture quality measurements Simultaneous Generate and Capture Charnel 2 Mode IP Capture Network Setting amp Fee E Siop Available Disk Space 34200 MB Packets Recorded Channel 1 Mode IP Capture v Network setting CEES Avalable Disk Space 34200 MB Packets Recorded Stream Selection J Capture To Capture To C Wideottest trp C Mideottest2 trp Crina Go too _ 2 channel capture Simultaneous 2 channel capture lets the user capture two live signals to use as reference and test videos in evaluating the device under test in Operation In both modes the captured compressed stream will be decoded to the uncompressed file by the embedded reference decoder and the user can run the picture quality measurement without any additional tool or manual processes Transcoder Capture Test IP Generate Reference IP www tektronix com 9 PQASW Datasheet Supported file format for IP interface The IP interface option can generate and capture compressed files in compliance with ISO IEC 13818 1 TS support over
23. mes frame rate reduction for mobile transmission and videophone teleconferencing and more can all be evaluated User interface of PQA showing reference test sequences with difference map and statistical graph 2 www tektronix com How it works The PQA takes two video files as inputs a reference video sequence and a compressed impaired or processed version of the reference First the PQA performs a spatial and temporal alignment between the two sequences without the need for a calibration stripe embedded within the video sequence Then the PQA analyzes the quality of the test video using measurements based on the human vision system and attention models and then outputs quality measurements that are highly correlated with subjective assessments The results include overall quality summary metrics frame by frame measurement metrics and an impairment map for each frame The PQA also provides traditional picture quality measures such as PSNR Peak Signal to Noise Ratio as an industry benchmark impairment diagnosis tool for measuring typical video impairments and detecting artifacts Each reference video sequence and test clip can have different resolutions and frame rates This capability supports a variety of repurposing applications such as format conversion DVD authoring IP broadcasting and semiconductor design The PQA can also support measurement clips with long sequence duration allowing a video clip to be quantif
24. oduct selection PQASW Datasheet Feature PQASW PQA600B PSNR PQR DMOS preconfigured measurements Yes Option BAS Multi resolution Frame rate support Ye pti BAS Multi results view options Yes Option BAS Embedded reference decoder Yes Option BAS Automatic temporal and spatial alignment Yes Option BAS IP Generation Capture Option IP Option IP User configurable measurements Option ADV Option ADV Attention Artifact weighted measurements Option ADV Option ADV XML scripting with Export Import files Option ADV Option ADV SD HD 3G SDI generation and capture No Yes HDMI without HDCP generation and capture No Yes HDMI with HDCP generation amp capture No Option BAS Video format conversion No Yes Tektronix is registered to ISO 9001 and ISO 14001 by SRI Quality System Registrar www tektronix com 19 PQASW Datasheet ASEAN Australasia 65 6356 3900 Austria 00800 2255 4835 Balkans Israel South Africa and other ISE Countries 41 52 675 3777 Belgium 00800 2255 4835 Brazil 55 11 3759 7627 Canada 1 800 833 9200 Central East Europe and the Baltics 41 52 675 3777 Central Europe amp Greece 41 52 675 3777 Denmark 45 80 88 1401 Finland 41 52 675 3777 France 00800 2255 4835 Germany 00800 2255 4835 Hong Kong 400 820 5835 India 000 800 650 1835 Italy 00800 2255 4835 Japan 81 3 6714 3010 Luxembourg 41 52 675 3777 Mexico Central South America amp Caribbean 52 55
25. osing Format conversion Cinema to SD DVD measurement class Format conversion SD to CIF measurement class Format conversion HD to SD measurement class Format conversion CIF to QCIF measurement class Use View model to resample shift and crop test to map to measurement Requires Option ADV 030 SD DVD from D Cinema Artifact weighted PSNR dB measurement Attention weighted objective measurements General differences PSNR measurement class 16 www tektronix com Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection NA Auto align Selected NA All artifacts NA dB units spatial selected 031 CIF from SD Broadcast Artifact weighted PSNR dB measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection NA Auto align Selected NA All artifacts NA dB units spatial selected 032 SD from HD Broadcast Artifact weighted PSNR dB measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection NA Auto align Selected NA All artifacts NA dB units spatial selected 033 QCIF from CIF and QVGA Artifact weighted PSNR dB measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection NA Auto align Selected NA All artifacts NA
26. rehensive picture quality analysis The PQA provides Full Reference FR picture quality measurements that compare the luminance signal of reference and test videos It also offers some No Reference NR measurements on the luminance signal of the test video only Reduced Reference RR measurements can be made manually from differences in No Reference measurements The suite of measurements includes Critical viewing Human vision system model based Full reference picture quality Casual viewing Attention weighted Full reference or No reference picture quality Peak Signal to Noise ratio PSNR Full reference Focus of attention Applied to both Full reference and No reference measurements Artifact detection Full reference except for DC blockiness DC blockiness Full reference and No reference The PQA supports these measurements through preset and user defined combinations of display type viewing conditions human vision response demographic focus of attention and artifact detection in addition to the default ITU BT 500 conditions The ability to configure measurement conditions helps CODEC designers evaluate design trade offs as they optimize for different applications and helps any user investigate how different viewing conditions affect picture quality measurement results A user defined measurement is created by modifying a preconfigured measurement or creating a new one then saving and recalling the user
27. results are displayed on screen and saved to the system hard disk The Review mode is used to view previously saved summary results and maps created either with the measurement mode or XML script execution The user can choose multiple results in this mode and compare each result side by side using the synchronous display in Tile mode Comparing multiple results maps made with the different CODEC parameters and or different measurement configurations enables easy investigation of the root cause of any difference stalled Sequences Multiple result display Resultant maps can be displayed synchronously with the reference and test video in a summary six tiled or overlaid display Six tiled display In Six tiled display the user can display the 2 measurement results side by side Each consists of a reference video test video and difference map to compare to each other Integrated graph In Summary display the user can see the multiple measurement graphs with a barchart along with the reference video test video and difference Overlay display reference and map map during video playback Summary measures of standard parameters and perceptual summation metrics for each frame and overall video sequence are provided In Overlay display the user can control the mixing ratio with the fader bar enabling co location of difference map reference and impairments in test videos Error logging and alarms are available to help u
28. s BT 500 Training 012 SD Sports Broadcast ADMOS measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection SD Broadcast ITU R BT 500 NA Typical NA Motion and DMOS Units Re CRT Foreground BT 500 Training Dominant 013 HD Sports Broadcast ADMOS measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection HD Broadcast ITU R BT 500 NA Typical NA Motion and DMOS Units Re CRT Foreground BT 500 Training Dominant 014 SD Talking Head Broadcast ADMOS measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection SD Broadcast ITU R BT 500 NA Typical NA Motion and DMOS Units Re CRT Foreground BT 500 Training Dominant Use any combination display model and viewing conditions with each measurement 015 SD DVD from D Cinema DMOS measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection DMD projector 7 scrn heights NA Expert NA NA DMOS Units Re and SD CRT 20 cd m and BT 500 Training ITU R BT 500 016 CIF from SD Broadcast DMOS measurement Display model View model PSNR Perceptual Artifact Attention model Summary node difference detection LCD and SD 7 scrn heights NA Expert NA NA DMOS Units Re Broadcast CRT 20 c
29. sers efficiently track down the cause of video quality problems All results data and graphs can be recalled to the display for examination www tektronix com 7 PQASW Datasheet Automatic temporal spatial alignment The PQA supports automatic temporal and spatial alignment as well as manual alignment Auto spatial alignment execution with spatial region of interest selected The automatic spatial alignment function can measure the cropping scale and shift in each dimension even across different resolutions and aspect ratios If extra blanking is present within the standard active region it is measured as cropping when the automatic spatial alignment measurement is enabled The spatial alignment function can be used when the reference video and test video both have progressive content In the case where the reference video and test video has content with different scanning interlace versus progressive or vice versa the full reference measurement may not be valid In the case where the reference video and test video both have interlaced content the measurement is valid when spatial alignment is not needed to be set differently from the default scale and shift Region of interest ROI There are two types of spatial temporal Region of Interest ROI Input and Output Input ROIs are used to eliminate spatial or temporal regions from the measurement which are not of interest to the user For example Input Spatial ROI
30. tasheet HL eee ai anam IN B Modulation sensitivity vs spatial frequency This model has been calibrated over the appropriate combinations of ranges for these parameters with reference stimulus response data from vision science research As a result of this calibration the model provides a highly accurate prediction The graphs above are examples of scientific data regarding human vision characteristics used to calibrate the human vision system model in the PQA Graph A shows modulation sensitivity vs temporal frequency and graph B shows modulation sensitivity vs spatial frequency The use of over 1400 calibration points supports high accuracy measurement results C Reference picture www tektronix com 3 PQASW Datasheet D Perceptual contrast map Picture C is a single frame from the reference sequence of a moving sequence and picture D is the perceptual contrast map calculated by the PQA The perceptual contrast map shows how the viewer perceives the reference sequence The blurring on the background is caused by temporal masking due to camera panning and the black area around the jogger shows the masking effect due to the high contrast between the background and the jogger The PQA creates the perceptual map for both reference and test sequences then creates a perceptual difference map for use in making perceptually based full reference picture quality measurements Comparison of predicted D
31. trolled environment with human viewers expressing their opinion of picture quality to create a Differential Mean Opinion Score or DMOS Extensive testing using this method can be refined to yield a consistent subjective rating www tektronix com 1 PQASW Datasheet However this method of evaluating the capabilities of a compressed video system can be inefficient taking several weeks to months to perform the experiments This test methodology can be extremely expensive to complete and often the results are not repeatable Thus subjective DMOS testing with human viewers is impractical for the CODEC design phase and inefficient for ongoing operational quality evaluation The PQA provides a fast practical repeatable and objective measurement alternative to subjective DMOS evaluation of picture quality System evaluation The PQA can be used for installation verification and troubleshooting of each block of the video system because it is video technology agnostic any visible differences between video input and output from processing components in the system chain can be quantified and assessed for video quality degradation Not only can CODEC technologies be assessed in a system but any process that has potential for visible differences can also be assessed For example digital transmission errors format conversion i e 10801 to 480p in set top box conversions analog transmission degradation data errors slow display response ti
32. y node difference detection Custom HD CRT 3 scrn heights NA Custom NA Typical DMOS Units Re BT 900 Training opecifications All specifications apply to all models unless noted otherwise Configuration nodes Display technology CRT LCD DMD each with preset and user configurable parameters Interlace Progressive gamma response Viewing distance ambient luminance for reference and test independently image cropping and registration automatic or manual control of image cropping and test image contrast ac gain brightness dc offset horizontal and vertical scale and shift Display model time etc reference display and test display can be set independently View model PSNR No configurable parameters Perceptual difference photosensitive epilepsy triggers etc 1 Requires Option ADV The viewer characteristics acuity sensitivity to changes in average brightness response speed to the moving object sensitivity to www tektronix com 17 PQASW Datasheet Configuration nodes Attention model Artifact detect Summary node Overall attention weighting for measures temporal Motion spatial Center people Skin foreground contrast color shape size distractions Differences Added edges Blurring removed edges Ringing Mosquito noise rotated edges Edge blockiness and DC blockiness Removed detail within a block Measurement Units Subjective Predicted DMOS PQR or Per
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