Archived posting to the Leica Users Group, 2002/10/27
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Hi Jim, > This is how I understand dpi as well. DPI doesn't really matter until you > send a file to your printer. Printers print in DPI (Dots Per Inch), and that DPI is typically somewhat fixed, say, 360/720/1440. You send PPI (Pixels Per Inch) to the printer driver, and these pixels get converted to printer dots. One printer dot is NOT the same as a pixel. Monitors display in PPI (Pixels Per Inch), but that is not how they are spec'd, and that number is typically not stated...because it is a function of the video mode/video card and monitor combination. A 21" (diagonal) monitor that displays 1600 x 1200 has an XY physical dimension of 3/4/5, so 21"/5 = 1600/X = 1200/Y so X = 16.8" and Y = 12.6", so your actual PPI resolution of the monitor is 1600/16.8 (or 1200/12.6, as the pixels are typically square) or ~95 PPI. > I believe the standard for Windows > nowadays is > 96dpi, I assume you mean for monitors? There really is no "standard", as it depends on the display mode, but in general, as you've said, the highest is around 96/100. To complete the "PI" (Per Inch) loop, scanner scan at SPI (Samples Per Inch) and the output of the scanner is Pixels...with no real physical dimension, though there is a size stored with the data, it is really irrelevant to the data, but is *possibly* used when you print the image...but that's a different issue entirely. Austin - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html