Archived posting to the Leica Users Group, 2010/06/09
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Hi Jean, Thank you for your details, I didn't do any calculation, I simply read the data of my scans. Believe me, I'm not really concerned by the pixels, in fact they are lovely, quite, silentious, discret... Fins aviat too! Lluis El 09/06/2010, a las 2:25, Jean Louchet escribi?: > Hi all, > > Sorry Lluis, I don't agree with your calculations. > A 6x6 neg. is actually 56x56 mm > At 3200 ppi it makes 3200 x 56 / 25.4 = 7055 pixels wide > hence the scan makes 50 MPixels (actually 49.77) > Then the file size depends on coding. In uncompressed raw (bitmap) > format such as .pbm, if using 8 bits per channel, it will use a memory > space of 50 MBytes in monochrome or 150 MBytes in colour. > > If one scans at 1200 ppi it makes 1200 x 56 / 25.4 = 2645 pixels wide > hence 7 MPixels. > A 8 bit-depth .pbm monochrome file will then be 7 MBytes. > A 8 bit - depth .pbm RGB (colour) file will be 21 MBytes. > > One should add the header sizes but this is negligible (.pbm headers > use 15 bytes plus the optional comments ) > > Some scanners may use more than 8 bits depth in order to give deeper > dynamics. > Once compressed it will use much less space, of course, but the > compression ratio depends on the picture itself and on coder > adjustments. > > Fins aviat, > Jean > >> >> >> Message: 6 >> Date: Tue, 8 Jun 2010 00:51:15 +0200 >> From: Lluis Ripoll Querol <lluisripollquerol at gmail.com> >> Subject: Re: [Leica] Film/slide scanner recommendations? Samples? >> Anyone use Braun? >> To: Leica Users Group <lug at leica-users.org> >> Message-ID: <91DA40FD-337F-484D-80A5-D0342CDDD273 at gmail.com> >> Content-Type: text/plain; charset=ISO-8859-1; format=flowed; >> delsp=yes >> >> At 3200 ppi 6863 x 683 pixels , 90 MB >> >> At 1200 ppi 2400 x 2400 pixels, 5,8 MB >> >> If you need others, let me know >> > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information