Olympus-OM
[Top] [All Lists]

Re: [OM] Homepage

Subject: Re: [OM] Homepage
From: John Hermanson <omtech@xxxxxxxxx>
Date: Tue, 16 Mar 1999 18:12:54 -0500
Someone once said (maybe on this group), that when you scan an image,
you should do it so you only have to scan it once, then use this "raw"
or "master" image for all future images, whether it be downsizing or
creating a thumbnail.  
And YES, there is a huge improvement in  resized image quality when I
use the "unsharp"  filter.  It really sharpens it (why do they call it
"unsharp"?)  This is part of the Micrographx PhotoMagic 6 suite.

I realize this is completely without OM content, but the feedback is
really helping.  Thanks for the bandwidth!

John

Sean Mooney wrote:
> 
> >>Right now I scan at 300 DPI, resize to 150 DPI, then "convert to web
> >>image" at 90 DPI.  I am still new at this.  Others may have a better
> >>technique.
> >>How do you scan  for the best results on the web?
> >>
> >>John
> >>
> >John,
> >
> >PMFJI, but all things being equal, you are probably better off avoiding any
> >resizing that you can.  So if you want to print at 300 dpi, try to scan to
> >that resolution.  If you have to resize, obviously it's best to resize
> >downwards, so scan initially to your highest needed resolution.
> <
> >
> >Remember that an ordinary photographic print usually has only about 100 dpi
> >worth of detail in it (so I'm told), or at the most about 200 dpi.  But
> >apparently scanning to the desired resolution for whatever output you want
> >and avoiding resizing is the ticket to the highest quality output.
> >
> >It looks to me as though you're doing it right, although I don't understand
> >why you're resizing to 150 dpi as an intermediary step.
> >
> >Joel
> 
>         I'm not sure I agree.  Scanning at high res and resizing for the web
> can be a good idea for a number of reasons.  First, for archival reasons a 
> high
> res digital image from a slide or print can act as a master were you can
> resize in the future without loss of color or detail -- without having to
> rescan.  Second, scanning at high res and resizing generally(IMO) gives a 
> better
> image than a low res scan.  This comes about because often scanners require a
> despeckle with perhaps a sharpening or blurring to the master, which upon
> resizing gives a much better image.  Finally, editing is much easier on
> a high res image than a low res one (such as manually removing spots,
> highlighting, adjusting balance, saturation, etc).
> 
>         I'm a little surprised there hasn't been a discussion about
> gamma here.  Gamma could (arguably) be the most important consideration
> when scanning and publishing images on the web.  The gamma values on
> a pc is about 1.0 less than a mac which is about .5 less than an (default)
> sgi.  Therefore images can appear to be a more than a stop lighter or darker
> depending on what machine you are viewing them with.  Therefore, if you
> have an image that is a little dark on an sgi, it will be too dark on a
> mac and nearly black on a pc.  Make sure you find middle ground that gives
> good results on all systems.
> 
> Sean Mooney
> Computer Graphics Laboratory
> University of California San Francisco
> 
>

< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >


<Prev in Thread] Current Thread [Next in Thread>
Sponsored by Tako
Impressum | Datenschutz