Simulation of atmospheric obscurants in photographic images

摘要

Processing is described which simulates the effects of atmospheric obscurants (fog, dust, smoke, etc.) in photographic images, Given a prescribed meteorological range (visibility) within the scene, the distance betwene the viewer and the object point, and the resulting beam transmittance along the line of sight; the beam transmittance, the color of the object point, and the color of the obscurant in the intervening atmosphere, are then used to calculate the color shift of the object point as seen by the viever. As the distance of an object point from the viewer increases, the color of an object approaches the color of the obscurant, and the contrast between the object and background decreases so that at some point (mathematically, the meteorological range) the object becomes invisible.