Pixel Density
Pixel density refers to the number of pixels in a given area. It plays a big role in determining the detail of information obtained and the total area covered by the camera. The pixel density of an image depends on several factors:
Camera resolution
Aspect ratio
Instantaneous field of view (IFOV)
Distance from camera to object
How to Calculate Pixel Density
Example Scenario:
Image size of Rayfin Mk2 with 12.3MP sensor is 4056 x 3040 pixels
FOV in water is min 81° diagonal, 71° horizontal, 57° vertical. 4:3 aspect ratio
The distance between camera and object is 2m
Using the formula below we can find the area covered
Width of image = 2 * distance * tan(FOV / 2)
Image width = 2 * 2000mm * tan(71/2) = 2850mm
Image height = 2 * 2000mm * tan(57/2) = 2170mm
Divide the vertical pixels by the coverage:
2850mm / 4056 pixels = 0.70mm/pixel
