[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-183489-105":59,"doc-detail-183489-en":130},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":123,"head_meta":125,"extra_data":127,"updated_unix":129},105,"en","understanding-mos-jnd-and-psnr-video-quality-measurement","Understanding MOS, JND, and PSNR - Video Quality Measurement","","Defines “video quality” using fidelity to measure how closely a processed or delivered signal matches a reference source, with focus on distortions introduced through networks or devices. Breaks video quality into picture quality, audio quality, and lip sync, and explains metrics and indices grounded in human visual/audio systems. Summarizes subjective testing as the most proven approach, including MOS scoring scales, error types in digital television, and guidance for mapping expert judgments via JND/DMOS to perceived quality.",{"@graph":69,"@context":122},[70,84,105],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":40,"@type":76,"position":81},"https://docshare.wps.com/document/research-report/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/understanding-mos-jnd-and-psnr-video-quality-measurement/183489/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/understanding-mos-jnd-and-psnr-video-quality-measurement/183489.png","ImageObject",300,407,{"name":92,"@type":93},"Lute","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-17","2026-09-02",true,{"@type":102,"interactionType":103,"userInteractionCount":52},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"How is “video quality” defined in this document?","Question",{"text":112,"@type":113},"Video quality is defined in terms of fidelity: how closely the processed or delivered signal matches the original (reference) signal, especially regarding distortions introduced through transmission or devices.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"What are the main components of video quality?",{"text":117,"@type":113},"It defines three components: picture quality (visual understanding), audio quality (auditory discernment), and lip sync (audio-video synchronization).",{"name":119,"@type":110,"acceptedAnswer":120},"How do MOS, JND, and DMOS relate to perceived quality?",{"text":121,"@type":113},"MOS quantifies subjective test scores on a numerical opinion scale. JND uses expert agreement levels to characterize just-noticeable differences, and DMOS ranges map these differences to observer satisfaction from dissatisfaction to perfect quality.","https://schema.org",{"og:url":83,"og:type":124,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":126,"canonical":83},"index,follow",{"doc_id":128,"site_id":62},183489,1788352884,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":39,"category_name":40,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":52,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":19,"language":139,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":140,"faqs":141,"seo_title":142,"seo_description":67,"update_tm":129,"read_time":52,"preview_page_count":4},137454149569,"https://ap-avatar.wpscdn.com/davatar_29158cc5080c5b710cf443261637dec0","| Understanding MOS, JND, and PSNR |  |\n| --- | --- |\n| Executive Summary\u003Cbr>The term “video quality” remains poorly defined even in cases when it seems that it shouldn’t be. Our goal is to provide a tool that is useful for troubleshooting a network or testing the ability of a compression algorithm to produce an appealing stream of pictures and sound. To that end, we are going to define “quality” in terms of fidelity: that is how closely does a processed or de‐ livered signal match the original source (or reference) signal? Our main concern will be to detect and quantify any distortions that have been introduced into the signal as it passes through a network or device.\u003Cbr>Quality measurement starts with a simple concept: we must judge video quality in a consistent way regardless of the typeof distortions created by different types of processing applied. |  |\n| General Video Quality Defined\u003Cbr>We are using video quality to define three major components:\u003Cbr>􀁸 Picture Quality – an index of eyes ability to understand the picture\u003Cbr>􀁸 Audio Quality – an index of the ears ability to discern the audio\u003Cbr>􀁸 Lip Sync – a measurement of the audio to video syn‐ chronization\u003Cbr>We are also going to define 2 terms:\u003Cbr>􀁸 Metric – an algorithm that quantifies differences\u003Cbr>􀁸 Index – an algorithm that measures quality using the Human Visual or Audio System (HVS/HAS)\u003Cbr>Ultimately, there is only one proven way to evaluate video quality and that is Subjective Testing. However, this is very expensive, time‐consuming, and often impractical. The main subjective quality methods are Degradation Category Rating (DCR), Pair Comparison (PC) and Absolute Category Rating (ACR) . The human subjects are shown 2 sequences (original and proc‐ essed) and are asked to assess the overall quality of the proc‐ essed sequence with respect to the original (reference) se‐ quence. The test is divided into multiple sessions and each ses‐ sion should not last more than 30 minutes. For every session, several dummy sequences are added, which are used to train the human subjects and are not included in the final score. The subjects score the processed video sequence on a scale (usually | 5 or 9) corresponding to their mental measure of the quality – this is termed Mean Opinion Score (MOS) .\u003Cbr>When the MOS score is on a 1 to 5 scale, the scores are\u003Cbr>1. Unacceptable\u003Cbr>2. Poor\u003Cbr>3. Fair\u003Cbr>4. Good\u003Cbr>5. Excellent\u003Cbr>The results can, of course, vary from test to test, but if the pool is large enough (16 or more), the scores tend to stabilize.\u003Cbr>Types of Errors\u003Cbr>Two types of problems can arise with digital television:\u003Cbr>􀁸 The digital transmission path can fall below acceptable levels and cause a complete loss – [i.e. no](i.e. no) picture and no audio.\u003Cbr>􀁸 The amount and quality of the compression can lend itself to poor quality.\u003Cbr>Checking digital transmission paths for errors is fairly straightforward. Sending a known signal and verifying that the received path is a bit‐for‐bit match. |\n\n| JND Score | Experts | Description |\n| --- | --- | --- |\n| 0 | 2 | The Experts Disagree on which is better |\n| 1 | 4 | 3 Experts pick the Reference and 1 picks the Processed |\n| 2 | 8 | 7 Experts pick the Reference and 1 picks the Processed |\n| 3 | 16 | 15 Experts pick the Reference and 1 picks the Processed |\n| 4 | 32 | 31 Experts pick the Reference and 1 picks the Processed |\n| 8 | 512 | 511 Experts pick the Reference and 1 picks the Processed |\n| 12 | 8192 | 8191 Experts pick the Reference and 1 picks the Processed |\n\n\n| DMOS | JND | Description |\n| --- | --- | --- |\n|  | 13+ | Check the Spatial and Tempo‐ ral Alignment |\n| 3.5-4.0 | 10-12.99 | Most Observers Dissatisfied |\n| 3.0-3.49 | 7-9.99 | Many Observers Dissatisfied |\n| 0.4-2.99 | 2-6.99 | Broadcast Quality |\n| 0.0001-0.39 | 0.01-1.99 | Production Quality |\n| 0 | 0 | Perfect Quality |\n\n\n| 3.1-4.0 | Most Users Dissatisfied |\n| --- | --- |\n| 2.1-3.0 | Many Users Dissatisfied |\n| 1.1-2.0 | Some Users Satisfied |\n| 0.7-1.0 ","cbCaiv5DaB9H9fsI","https://ap.wps.com/l/cbCaiv5DaB9H9fsI","pdf",318058,"English","# Executive Summary\n# General Video Quality Defined\n## Picture Quality, Audio Quality, Lip Sync\n## Metrics and Indices\n## Subjective Testing and MOS\n# Types of Errors\n# JND Score\n# DMOS and JND Mapping\n# DMOS Ranges","[{\"question\":\"How is “video quality” defined in this document?\",\"answer\":\"Video quality is defined in terms of fidelity: how closely the processed or delivered signal matches the original (reference) signal, especially regarding distortions introduced through transmission or devices.\"},{\"question\":\"What are the main components of video quality?\",\"answer\":\"It defines three components: picture quality (visual understanding), audio quality (auditory discernment), and lip sync (audio-video synchronization).\"},{\"question\":\"How do MOS, JND, and DMOS relate to perceived quality?\",\"answer\":\"MOS quantifies subjective test scores on a numerical opinion scale. JND uses expert agreement levels to characterize just-noticeable differences, and DMOS ranges map these differences to observer satisfaction from dissatisfaction to perfect quality.\"}]","Understanding MOS, JND, and PSNR - Video Quality Measurement | PDF"]