In the first two articles of this series, we covered the basics between temporal and frame-based compression and identified nine elements that should be considered when designing, specifying, or buying a high quality network video surveillance system. In the first and second articles, we reviewed the first 7 of our 9 considerations. In this article, we will deal the last two. To review, the nine considerations are:

1. RESOLUTION [User Requirement] (Article 1)
2. FRAME RATE [User Requirement] (Article 1)
3. WEATHER [Video Environment] (Article 2)
4. LIGHTING [Video Environment] (Article 2)
5. SCENE MOTION [Video Environment] (Article 2)
6. OBJECT SPEED [Video Environment] (Article 2)
7. CAMERA MOTION [Video Environment] (Article 2)
8. RECORDING [User Requirement]
9. LIVE VIEWING [User Requirement]

Our considerations fall into two categories: "User Requirement" which will vary depending on the customer's preferences, and "Video Environment", which are the variables in an application that will likely have an impact on video quality.

To frame the discussion of our final two considerations, it is our position that a video system should always be optimized to achieve a desired image quality, and then adjusted for frame rate to maximize bandwidth and storage efficiencies. When dealing with MJPEG, we encourage a compression setting no lower than medium (MJPEG= 50). With H.264, we recommend nothing lower than the main profile and that you allow the bit rate to vary (VBR) to ensure delivery of the best quality image. Remember, the customer is paying for a video recording system that meets their expectations in all conditions, not just the optimal conditions - that is a big difference. System designers and architects must work diligently to guarantee that the choices made during the design and configuration of the system do not degrade the video's quality during those times when events occur.

RECORDING [User Requirement]