Task-Based Video Quality Update Or, what has Carolyn been up to this past year? VQEG, June 2009

Last You Heard Background –Video quality research for task-based video –Initial application: public safety agencies Measurement: P.912 approved –“Video Quality Assessment Methods for Recognition Tasks” –No scales!!

Since Then Video Quality in Public Safety (VQiPS) Conference convened 2/09. Outcomes –Working Group under Dpt of Homeland Security –Active projects: Use cases Glossary Standards inventory Scene pool creation

Use Case Project Old way of thinking: –Every application its own use case E.g. police in-car cameras, fire, EMS, SWAT New way: –Each case boils down to “visual intelligibility” of an intended target –Extract common scene parameters that affect the ability to recognize a target –Determine set of discrete values for each parameter –Design use cases based on permutations of parameters

Use Case Parameters

Parameter Definitions Use Paradigm Use Timeframe – is the video used for real-time applications or recorded for later use? –Li – Live, or real-time. –Re – Recorded. Discrimination Level – what is the end user’s ultimate goal? –EA - General Elements of the Action (e.g. people present, high-level description of actions that took place). –TCl - Target Class Recognition (e.g. car vs. van). –TCh - Target Characteristics (e.g. gender, markings, smaller actions). –ID - Target Positive ID (e.g. face, object, alpha-numeric). Scene Content Target Size – how much of the frame does the object or person of interest occupy? –Lg – Large, the target occupies a large percentage of the frame. –Sm – Small, the target occupies a smaller percentage of the frame. Scene Complexity – how much motion (either target or camera) and how much spatial detail is in the video frame? –Hi – High complexity, there is a lot of motion or edges in the video. –Lo – Low complexity, there is not much motion, or many edges. Lighting Level – is the lighting generally uniform, or are is there near-black to daylight ranges in the video frame? –CstH – Constant lighting, at a comparatively bright level. –CstL – Constant lighting, at a comparatively dim level. –Var – Variable, the range of light in the scene varies from bright to dim, either within one frame, or over time.

Obvious Questions What is “small” or “large” What is “complex” What is a high dynamic range for lighting Etc

Glossary Project Merge existing documents from –Forensic video community –Security video community –others

Standards Inventory Project Actually a matrix –Type of standard Specifications (actual numbers) Algorithms Test methods (Evaluation) Operating Procedures Definitions and Units Models –Component of video system it applies to

Video System Components 1Scene Content 2. Optics7. Display3. Capture4. Processing 5. Transport 6. Storage Figure 1: The Video System

StageSpecAlgEvalDef’nOpsModel Scene Optics Capture Process Xport Display Standards Inventory

Future Performance Specification recommendations –Subjective testing based on use cases Models –Bitstream?