Archived posting to the Leica Users Group, 2010/06/08
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]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 >