[softwarelist] Re: Importing TIFFs into OPW

Gavin Crawford wrote: 
In article <44809B77.3020501@xxxxxxxx>,
   Clive Bonsall <C.Bonsall@xxxxxxxx> wrote:

They are 8bpp grayscale images, scanned at 1200dpi in Photoshop CS2. 

Is there a need to use such big images? You said in a previous posting
that they were line art, if that is the case, then line art only needs
to be 1bpp (i.e. black and white). If the images are in fact 8bpp and
use more than 2 colours, then I doubt you need them at 1200dpi -
certainly not is that is the final output resolution.

I seems to me that you are using excessively large images than you need
to be using. Maybe you could say what the intended production method
is for this document? It helps to know how a job is to be printed so you
can make the correct judgement on image resolutions etc.

I know this is not really relevant to the discussion of the problems
with loading TIFFs but once it is clear how the job is being printed
people can give helpful suggestions as to what sizes the images need to
be.

Thanks for this. Undoubtedly, I am using bigger images than I need to. But I'm unsure about the optimum mode/dpi setting to use, so advice would be appreciated.

For non-colour stuff, I tend to scan everything at 8bpp grayscale and the highest resolution (dpi) that my computer can manage, because I can always reduce the images to 1bpp and/or lower resolutions, as/when required.

The JOB is this ... a book DTP'd using OPW, which will contain lots of line drawings and B&W photos. It will be sent to a commercial printer either as camera-ready copy or as a series of PDF files. For the line drawings what would be the optimum resolution -- e.g. is there anything to be gained by having the images at 1200dpi or even 2400dpi, or will 600dpi suffice? In the process of generating a PDF, downsampling of images normally occurs. In Acrobat Distiller, if bicubic downsampling for monochrome images is set to 1200dpi (as in Distiller's press quality mode), is there any point starting off with an image that is larger than that?

For information, these are the guidelines issued by CUP for a publication I contributed to recently:

"All illustrations, either as CRC (line figures), prints/transparencies
(photographs) or as digital images.  If you're submitting the images
digitally then they should be saved at a minimum resolution of 1200 dpi for
line figs/300 dpi for photographs, when saved at the size at which they'll
be reproduced in the book.  TIFF or EPS files, please."

In this case I found that my computer (Athlon 2600+, 1GB memory) couldn't even manage to save 1200dpi TIFFs of some of the illustrations (those that included grey tones) -- 800dpi was its limit. Yet this is what many publishers are asking for.
--
Clive Bonsall
C.Bonsall@xxxxxxxx

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