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Re: Interpolation



>>To interpolate is to create a data point in between two existing data
points.
>>Interpolation would create more pixels.


>Actually, removing data samples is called decimation, and should include a
>filtering step to avoid artifacts

These terms are always confused and mis-applied.

Definitions from various Engineering books (shortened to get to the point
quickly):

Interpolation:
" A process by which a value is placed between tabulated values of a
function. "
Martin's note:  You can do liner or polynomial/FIR based interpolation to
reduce artifacts.

Extrapolation:
"Estimation of a value outside of the range of tabulated values".

Decimation:
"Reduction of sample rate by removing samples"
Martin's note:  Again, FIR low pass filtering is usually done.

I'm not saying that throwing away samples is correct.... all I'm saying is
that this is what is being done for a great deal of major motion picture
effects work.  Theory versus practice.

-Martin



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