Because different wavelengths of light are scattered differently in air (there are actually two distinct types of scattering involved) light on the red end of the spectrum is scattered far more than light on the blue end, so things in the distance appear blue and somewhat washed out — aerial perspective.
I have a large number of photos. I know the distance to the subject in every photo. It is large enough that their is some aerial perspective, which they would look better without. I want to correct it automatically based on the distance involved. I don't want to correct them by hand.
Does anyone know, or know a source for, the degree of loss in different wavelengths of light over a distance D?
Does anyone know, or know a source for, the degree of ambient background light of a given wavelength accumulated washing out an object at distance D?
Yes, I know these would depend on all sorts of factors to get exact just like the color of the sky does, but I'm sure someone has studied reasonable averages for middle of the day photos.
The cheap version
The above is what I am really after, but if nobody can answer that, the simple version is this: If I know the distance D in a photo to a subject, what percentages would I use to mix the subject photographed close up and the sky to the get the same aerial perspective effect. This really isn't the same, but if it is the best I can get, I will take it.