Re: Lanczos interpolation

Mark Herring <[EMAIL PROTECTED]> writes:

>Wow!!!  I dont know about the other NG, but very few of us in R.P.D.
>have any clue what you are taling about.

>To many of us, interpolation is just a sleazy trick by a few fringe
>camera makers to pump up their Mp ratings

One might hope that the inhabitants of the image processing newsgroup
would know more about interpolation.

If you think it's used only to increase megapixel ratings of cameras,
you have an incredibly limited view of what interpolation does.

Interpolation, and more generally image resampling, is used every time
a digital image has its pixel density changed (resizing smaller as well
as larger) or it is rotated or has perspective errors corrected.  It's
used by the printer driver every time you print an image, unless the
image happens to be at exactly the PPI needed by the printer hardware.
It's used to reconstruct RGB images taken by Bayer sensors.

It's true that you can have "empty" interpolation that increases image
size with no useful purpose at all.  The "digital zoom" present on many
cameras is probably what you are thinking of, or the option on Sigma's
raw converter that produces a 13 MP image file from 3.4 MP of actual
data.  But most uses of interpolation in digital imaging are for a very
good reason.

        Dave