Digital BW, The Print

BTW => Native resolution = OPTICAL resolution
  -----Original Message-----
  From: Peter Marquis-Kyle [mailto:petermk@...]
  Sent: Thursday, June 06, 2002 7:04 PM
  To: DigitalBlackandWhiteThePrint@yahoogroups.com
  Subject: Re: [Digital BW] Re: Native resolution for scanning


  > Austin, I checked out the info on the epson site about the 2450, and
read that
  the resolution is 2400, but no mention of NATIVE RESOLUTION, Is the answer
to
  the question 2400?
  > David

  I'm not Austin, but I'll speak up. Yes, you got the right answer.

  Think of native resolution as the highest resolution the scanner can do
without
  interpolation (where new pixels are 'created' by the software).

  The Epson 2450 can scan at 2400 x 4800 samples per inch. Imagine a row of
  sensors spaced at 1/2400 inch, which steps across the original at 1/4800
inch
  intervals. But your image editing program (Photoshop or whatever) can't
deal
  with pixels that are not on a square grid.

  To use the 2400 x 4800 scan the scanner software has to interpolate to
4800 x
  4800, by 'inventing' the missing pixels by averaging the neighbouring
pixels. If
  you tell the scanner to sample at 2400 x 2400 the sensors step across the
  original at 1/2400 inch intervals, and every pixel is 'real'. Native
resolution.

  Peter Marquis-Kyle


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