lzw is a lossless compression and not a loosy compression like jpg so it is n ot surprising that one can sometimes get larger file than an uncompressed file. Since in some cases nothing is lost when there are few repetitive patterns of data in the image file, the addition of metadata overhead will make the file larger than if it had not been compressed at all. As often as not, this has nothing to do with the gainy or noisy character of the scan or the file per se.
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Monday, November 24, 2003 3:01 PM To: [EMAIL PROTECTED] Subject: [filmscanners] Re: FW: VueScan file size What file format are you saving to? The size VueScan gives you is the raw image size. The disk file size can be different, mostly smaller, due to how the information is saved. I have seen very grainy/noisy scans that when saved as tiff/lzw exhibit what I call "negative compression"--the compressed file is actually larger than an uincompressed file! The other possible culprit is that VueScan gives you the option to save as 16-bit and/or with the infrared as a fourth channel. I'm not sure that either of these would show up in the raw size, but they would make the file size go up Thomas Maugham wrote: > Sorry, that should read "119,885kb or 119.9mb". > > Tom > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of Thomas Maugham > Sent: November 22, 2003 2:28 PM > To: [EMAIL PROTECTED] > Subject: [filmscanners] VueScan file size > > I just scanned a negative and got the following information from > VueScan: "5576 x 3669 pixels 4000 dpi 1.39 x 0.917 inch 92.1 mb". The > size of the file on my hard drive is 119.885kb or about 119.9 mb. Why > the discrepancy between what VueScan says the file size is versus the > size on the hard drive? > > TIA, > Tom > > -------------------------------------------------------------------------- -- > ------------ > Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe > filmscanners' > or 'unsubscribe filmscanners_digest' (as appropriate) in the message title > or body > ---------------------------------------------------------------------------- ------------ Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body --- Incoming mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.537 / Virus Database: 332 - Release Date: 11/6/2003 --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.537 / Virus Database: 332 - Release Date: 11/6/2003 ---------------------------------------------------------------------------------------- Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
