[EMAIL PROTECTED] (2002-04-12 at 0919.27 -0500):
> > Can anyone tell me the difference between dpi, ppi and
> > lpi ? If my intention is to print a picture measuring
> > 8"x10", at what resolution should I scan ?
> dpi = dots per inch
This causes confusion, some file formats say DPI, and monitors
too... but IMHO they should say PPI. Dots per inch, but what kind of
dots? Multilevel ones like pixels? Single level like ink jets? Single
level but mix capable like dye based printers (so multilevel)?
> ppi = pixels per inch
What monitors and files have.
> lpi = lines per inch
Or how many different lines of a set of shades you can have per inch
with a halftoning printer (newspapers, laser printers, normal ink
jets). The more shades (b&w, 16 grays...) you want the less lines you
can paint (the less fine the detail is), but more intensity levels
avaliable (always supposing same printer).
> to know the minimum you need to scan you'll need to know what sort of dpi
> your printer is capable of printing.
> 8000 x 10,000 pixels!
Umm, eeeeeek! The guys I know work at 300-400 DPI and A4 (210 * 297
mm) output, that gives around 3300 * 4700 pixels, less than 8000 *
10000. And they do not use home printers, but professional machines
with good inks and papers. For home ones I guess 200-300 is more than
enough, and that means 2400 * 3300 for a full 8*10, so check what size
the original is, and scan so you get that many pixels.
> Pretty easy eh?
It is not. You will always find problems, due inexperience, not fixed
definitions or whatever. Some references are http://www.aim-dtp.net/
and http://desktoppub.about.com/library/weekly/aa101800a.htm, in this
last one they already say that terms are mixed, and they add SPI
(samples, about scanners, normally called DPI or PPI, being PPI the
most near, cos a "pixel is sample", IMO).
OK, I think I made it even more confusing now. :]
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