Digital BW, The Print

John,

You wrote:

>...
>The absence of combing in the resized image is not a sign that it's
>'better', it's a sign that information has been lost. ...

True.  Downsizing clearly eliminates information.  I suspect the information
lost is beyond what can be seen.

So, the problem and cure -- that is, both the "combing" and the downsizing
(that I would do anyway) -- are probably irrelevant to the ultimate image
quality of the print.  I found it was not worth my time to print over 360
dpi anyway.

Paul

_______________________-
  -----Original Message-----
  From: John Brownlow [mailto:lists@...]
  Sent: Tuesday, March 19, 2002 11:13 AM
  To: DigitalBlackandWhiteThePrint@yahoogroups.com
  Subject: Re: [Digital BW] Combing cure -- change size after the curves
areapplied


  On 3/19/02 2:01 PM, "Paul Roark" <paul.roark@...> wrote:

  > The very last step I now take is to change the size of the image in
  > Photoshop from the scanner's native resolution to my print size at 360
dpi.
  >
  > When I check the histogram there is no combing.
  >
  > I have not analyzed prints to see if I can see any difference.

  It is obvious why this eliminates combing. When you resize, Photoshop
  interpolates between the discrete values that represent the teeth of the
  comb to arrive at the pixel values for the new image.

  For example, let's say you have two neighboring pixels, one with value 150
  and one with value 175, and the image displays combing between these two
  values. Downsampling will probably produce a pixel in this region of the
  photograph with an intermediate value of around 165. Thus you now have
some
  pixels with the intermediate value where previously there were none.

  The absence of combing in the resized image is not a sign that it's
  'better', it's a sign that information has been lost. You could also
  eliminate combing by applying a 1 or 2 pixel radius gaussian blur before
  printing, but I don't suppose anyone is doing that.

  --
  John Brownlow

  http://www.pinkheadedbug.com


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