Re: Apple II Reference Manual Addendum PDF now online

[Mike Maginnis <maginnis@tarnover.org>]

On Mon, 27 Jun 2005 21:26:35 +0200, Paul Schlyter
<pausch@NOSPAMsaaf.se> wrote:

>In article <avXve.78228$HI.71270@edtnps84>, 
>to.email.me@post.a.request.message says...
>

--<snip>--

>
>Yes: never store the images as JPG when small detail is
>important.  Instead choose a file format with non-destructive
>compression, such as GIF, PNG or TIFF.  To cut down the size
>of the image file as much as possible, instead try to minimize
>the number of colors in the image.  These images are frequently
>black-and-white, so scan them in as such - or convert the image
>after the scan from "color" to "greyscale".  Next, cut down the
>number of grey levels as much as possible.  16 grey levels usually
>works fine here (each pixel will then only occupy 4 bits of data
>in uncompressed form).  Even just 2 grey levels may work (i.e. just black
>and white, no shades of gray) - if so, the size of the image is really 
>minimized, since each pixel will then occupy only one single bit in
>uncompressed form.  A 2 gray level b&w image, saved as a GIF file, can
>be considerably smaller than a JPG file at the same resolution - this
>may allow you to scan the image at still higher resolution, without
>the GIF file getting larger than the JPG file at the original resolution.

So far, in the several recent discussions on scanning quality I've
seen, several comments have been made all suggesting reducing gray
levels and bpp.  Is there a place I can find step-by-step instructions
(ie, click here, here, here and select this) on how to do this in
Photoshop?

- Mike
maginnis@tarnover.org

The Computist Project
http://www.computist-project.net