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Subject:Re: scanned images From:PERTTI MSigmaKITALO <PMAKITAL -at- NIPPI -dot- HUT -dot- FI> Date:Mon, 19 Dec 1994 16:54:31 GMT
Paula & Chad
You can lower the quantity that images take from your hard disk with
halftoning the images if you know what resolution is needed in
Let say you have 600 dpi printer and you want to print out images
with 32 shades of gray. Then you can halftone the image with the 106
lpi(lines per inch) halftone frequency.
(printer resolution dpi / halftone freq. lpi)^2 = nr. of gray shades
You can test with your pictures what gray shade level is appropriate
for you and then halftone your pictures according to that. After
halftoning images don't look so nice on the screen, though.
> Many times when you scan images into a PC the files can get
> quite large (as you well found out). The next time you scan (I don't
> know what software you are using or if you even have the ability to
> manipulate these scanned images) make sure you check things such as
> resolution and color versus b&w. You'll be surprised at the
> differences in your files sizes if you use lower scanning resolutions
> and b&w.
> Also, if you have access to an application called Adobe
> Photoshop it will allow you to change the color (usually RGB) scans
> from full to something called indexed color. This one switch has
> sometimes halved my image file sizes.
> I think the one thing to remember is that just because an
> image looks good on screen, it doesn't mean that it will look good on
> paper. I don't know my numbers here, but a screen can only output 72
> dpi where a standard office laser printer can output in upwards of 600
> dpi. If you play around further with scanning, you'll find little
> things like these that can save you and your hard drive space.