Question with exposure correction

PIX4Dmapper PIX4Dmapper Questions/Troubleshooting
1

In the Camera Requirements For Precision Agriculture document, it states that exposure correction (step 3) calculates a new pixel value (i.e. a new digital number) after considering exposure time, f number and ISO Speed. My question: What are the units of the correction? For example, does the correction apply exposure time in seconds (or milliseconds etc.)? I am trying to apply this equation myself to the images, but I get really large values, mainly because of a large correction factor.

Also, I cannot find a metadata tag associated with “ISOSpeedRatings” below that equation - is there another name for extracting this information?

2

Hi GR,

The questions addressed are linked to intellectual property rights. I am not sure how much it would help you, but I would recommend you to take a look here for an example of how the reflectance is estimated for Sequoia camera.

 

Cheers,

Ina