what parameters of CIVignette mean

Question

I check CIVignette of Core Image Filter Reference at http://developer.apple.com/library/mac/#documentation/graphicsimaging/reference/CoreImageFilterReference/Reference/reference.html#//apple_ref/doc/filter/ci/CIColorControls

and play around a with the parameters: inputRadius inputIntensity and still have not exactly understood what each parameter effects. Could please someone explain?

Answer 1

Take a look at wiki understand what vignetting in photography means.
It is the fall of of light starting from the center of an image towards the corner.

Apple does not explain much about the the params.

obviously the radius specifies somehow where the vignetitting starts

the param intensity i expect to be how fast the light goes down after vignetting starts.
The radius may not be given in points, a value of 1.0 relates to your picture size.