Archived posting to the Leica Users Group, 2001/07/24
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Austin writes: > I believe your premise is flawed. You need to > sample at slightly more than 2x the maximum frequency > you want to acquire. A scanner IS a data acquisition > system. 53 lp/mm is 106 lines/mm, which, as > you say, is ~2700 SPI. In order to assure that > the scanner can actually "acquire" all the lines, > both black and white (which is what a line pair is), > you would need to sample at > 5400 SPI. No. 2700 dpi is sufficient. 2700 samples per inch = 1350 cycles per inch = just over 53 cycles (i.e., line pairs) per millimetre.