Outreach / Video Quality Resources / Tools for Public Safety / Guide to Defining Requirements

Guide to Defining Video Quality Requirements

Jump To: Use Cases | Use Classes | Generalized Use Class Aspects | GUC Questionnaire | GUC Example | Video System Tasks | Video System Functions | Recommendations Tool | Acknowledgments


Revised May 29, 2012

DHS/OIC, in partnership with the PSCR program formed the VQiPS working group to help public safety agencies with little or no technical expertise in video describe their video quality needs and provide basic guidance for the selection of key video system components. DHS PDF report version available here.

Success and adoption of a video system involves many factors including installation, testing, support, redundancy, and training. To select a public safety video system it is important to understand how the quality of a video stream can be affected as it travels from the scene (camera) through the system to the viewer watching the scene on a remote display.

Video Quality in Public Safety

Video quality is judged by its delivery to the viewer in a manner in which she can accurately recognize what she needs. Required Video Quality often applies to many aspects of this function, but the VQiPS working group refers to it broadly as video quality. Visual intelligibility and visual acuity can also refer to aspects of video quality. These terms compare well to a visual extension of a “can you hear me” audio test, rephrased as “can you see me?”

Getting Started

Defining requirements for the video quality you need breaks down to four main steps:

Highlights the steps in the process for definfing video quality requirements.
  1. Identifying use cases

  2. Generalizing use cases into use classes

  3. Tip: Apply the Generalized Use Class Questionnaire to each use case you identify to translate them into generalized use classes where two or more use cases constitute a given use class.

  4. Understanding core video system tasks and functions supported by equipment

  5. Matching use classes to video equipment

  6. Tip: Use the Recommendations Tool for Video Requirements.