Guide to Defining Video Quality Requirements
| Getting Started | Use Cases | Use Classes | GUC Aspects | GUC Questionnaire | GUC Example | Video System Tasks | Video System Functions | Recommendations Tool | Acknowledgments |
Generalized Use Class Questionnaire
Apply the Generalized Use Class Questionnaire to each use case you defined to translate them into generalized use classes where two or more use cases constitute a given use class.
Your agency or organization might have more than one use case associated with its mission. Carefully define and analyze each of your use cases to determine the overall most restrictive use class. For example, if police and fire departments are sharing a video system, officers might need to recognize individuals with high-level detail, while firefighters might only need to recognize the presence of smoke. In this case, the police department has a more restrictive use case. Click on Generalized Use Class Questionnaire to download this one-page PDF form file.
Using the questionnaire below, click on a generalized use class aspect for more information.
Usage Timeframe - Use Characteristics
Consider: In what timeframe will the video be used? As in, will the video be used real-time or will it be recorded?
|The video will be viewed at the same time it is being shot||[ ] Live or real-time||Security monitor being viewed by security personnel|
|The video will be saved and capable of being played back||[ ] Recorded||Forensic video|
Discrimination Level - Use Characteristics
Consider: What level of discrimination do you need to recognize a target of interest?
|Use Discrimination Level||Characteristic||Example|
|High-level description of actions that took place||[ ] General Elements of the Action||People or person present|
|Large-scale recognition||[ ] Target Class Recognition||Car vs Van|
|Medium-scale detail recognition||[ ] Target Characteristics||Gender, markings, smaller actions|
|Enough detail to make a positive recognition||[ ] Target Positive ID||Face, object, alpha-numeric|
Target Size - Scene Content
Consider: What is the size of the object of interest with respect to the field of view?
|Scene Target Size||Content|
|[ ] Large||The target occupies a large percentage of the frame|
|[ ] Small||The target occupies a smaller percentage of the frame|
Motion - Scene Content
Consider: What level of motion do you anticipate in a scene of interest?
|[ ] High||A high-complexity video contains a lot of motion or edges|
|[ ] Low||A low-complexity video contains little motion or few edges|
Lighting Level - Scene Content
Consider: What level of lighting do you anticipate in a scene of interest?
|Scene Lighting Level||Content|
|[ ] Constant Lighting - Bright||At a comparatively bright level|
|[ ] Constant Lighting - Dim||At a comparatively dim level|
|[ ] Variable||Ranges from bright to dim|