Software Color Correction vs. Lighting: Video White Balance

user-interface

#1

The question:


1. Does the onboard camera have a white balance feature? Can that feature be accessed via the software driver? And can someone volunteer to make it available in the GUI? (click a keyboard button to cause the white balance menu to display).

2. Does any one have any ideas for mounting lighting separately from the camera housing? Typical light arms would produce too much drag, perhaps a bullet style light with on a fixed plastic arch.

The Problem:

1. Cameras are unable to automatically produce natural colored photos underwater, the effect gets worse with depth. The reason for this is the filtering property of water, color disappears as light travels through water. The red portion of the light drops off around 15ft and disappears entirely at 30ft.

2. Open ROV uses lighting in the same plane as the camera viewing angle causing:

White balance icons

  • floating particles to reflect brightly in the direction of the camera
  • ideally the lighting is in its own housing at a distance and angle from the viewing plane of the camera.

Possible Solutions:

3. @ Depths < 30ft : White Balance and/or Physical filters.

Photographers use either manual white balance control or special physical filters to perform color correction.

  • White balance should be adjusted as one gets deeper. One requires a known white color swatch to be mounted to the ROV.
  • Many cameras offer manual white balance control.
  • For good results, special underwater color correction filters are required, like those supplied by UR/Pro and Magic or underwater housing manufacturers.

4. @ Depths > 30ft:Lights and White Balance Required

At depths >30ft colored light is no longer present and one must use an alternate light source to bring natural color back.

  • For optimal results you must set your cameras white balance to match your light source. Different light sources have different temperatures.
  • Range of lights underwater is a few meters so you have to get close to the subject.
  • White balance via RGB histogram.RGB Histogram

5. Image processing with software.