Here is a new document about cameras for viewing on dashboards. From the introduction:
Please let me know if you spot mistakes or points that need clarification. It’s already pretty long and I don’t think it is possible to cover all the variations that are available, but I hope this captures some techniques and information that are useful to others.
# Selecting and Configuring Cameras for Driver Dashboards
## Overview
For many years our team has spent a more-than-reasonable amount of time each year trying to configure our cameras to work well on our dashboard displays. This fall I decided to look into the situation. I found a bunch of useful information that is not easily discovered.
The difficulty stems largely from the fact that WPILib documentation for cameras is mostly focused on vision tasks and thus doesn't cover cameras for the driver station very thoroughly.
One obstacle is that the camera specifications and documentation typically available are woefully inadequate to predict whether a particular camera will be a good choice for a driving and/or vision camera. Finding out even the set of supported pixel formats, resolutions, and frame rates is essentially impossible until you hook up the camera. Discussion of inherent camera latency and the way camera settings interact with one another to constrain achievable frame rate is nowhere to be found.
On the WPILib side also there are interactions between settings in different parts of the code and configurations that can have profound impact on achieved performance.
This article aims to fill some of that gap and tries to give a solid foundation for experimenting with cameras, camera configurations, dashboards and dashboard viewer configurations that will lead to repeatable behavior that meets teams' needs for viewing cameras on their driving dashboards.
## Considerations for a driver dashboard camera
The uses for a driver dashboard camera vary from game to game but there are a number of common characteristics. From the perspective of the drive team, the most important are likely: camera field of view, image clarity, and image delay -- how long does it take for something that is seen by the camera to show up on the dashboard?
The field of view is governed by the camera, its lens, and the aspect ratios that it supports, typically 4:3, 16:9, or 16:10. The latency is affected by the camera itself, the frame rate, and the time to do any processing such as resolution scaling and compression -- typically performed by the roboRIO or a coprocessor as well as the time to transmit the image over the network to the dashboard computer.
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