Digital BW, The Print

Hi Joel,

Decimation is a process by which you decrease the amount of data.
Technically, it originally meant 1 out of 10 was removed, but in signal
processing, it simply means N removed.  If you have an image that is 320
pixels across, and you want to downsize it to 160 pixels across, every other
pixel would be removed.  It can be done by simple removal, or by doing it
algorithmically...in a simple sense, taking two pixels and averaging them
together and replacing the two values with the one averaged value.

Regards,

Austin


> Hello:
>
> coudl you clarify what you mean by "decimating the image" in PS?
> Where is the "little box" in resizing that
> allows/disallows "decimating."
>
> Thanks,
>
> joel
>
>
> --- In DigitalBlackandWhiteThePrint@y..., "Austin Franklin"
> >
> > The reasoning is pretty obvious.  Decimating the image information
> means
> > that you are changing the image data that the halftone algorithm is
> basing
> > its decisions on, and that will degrade your output tonality and
> sharpness.
> > Now, this isn't true with EVERY image on earth, but as a general
> rule of
> > thumb, for me, it has held true.
> >
> > It is a very easy test you can do for your self.  Scan an image,
> resize to
> > your output size in PS NOT allowing decimation to take place, and
> let the
> > PPI fall where they may to 240PPI.  Print the image.  Take the same
> image
> > and check the little box in re-size to allow decimation, and then
> change the
> > PPI to 240.  Print it out.  See for your self ;-)
> >
> > Regards,
> >
> > Austin