[ANSIART]

===============================================================================

To: ALL Number: 4577
From: REZ <RIVIDH.MINUSTHISPART Refer #: None (Echo)
Date: 01-23-01 05:30 Recvd: No
Subj: Re: bulk zip batch file? Conf: 63 I_DOS.Tips
BBS: The Safe House -------------------------------------------------------------------------------


Dirk Loedding wrote:

So how is it that a .GIF or .JPG file can be so small compared to the
BMP it was converted from, without any apparent loss of picture quality/information?

Convert the JPG back to a BMP and you'll see how much data was lost; the resulting BMP looks like crap. As to GIF, convert it back to 16M colours
and watch what happens. It'll usually turn out fairly patchy-looking.

A lot of it is how well the format fools the eye. GIF (256 colours) does
pretty well so long as the eye only expects line-art type results, but generally looks poor in a photo -- your face can wind up with pink and
yellow splotches, depending on what's the dominant colour left after
most have been filtered out. So GIF isn't great for photos, but is good
for other artwork. OTOH JPG has the same colour depth as BMP, but cuts
out a lot of "you don't notice this anyway" type data. So photos look
pretty good, but artwork can look really crappy as a JPG!

Mind you this is about 110% of my technical knowledge of the subject :)
.






---
þ RoseMail 2.55á: ILink: FONiX Info Systems * Binfield, Berkshire UK






¯ ®
¯ Barry_Martin_3@ ®
¯ @Q.COM ®
¯ ®


... Pets are for life, not for Christmas.
--- MultiMail/Win32 v0.47
þ wcECHO 4.2 ÷ ILink: The Safe BBS þ Bettendorf, IA

--- QScan/PCB v1.20a / 01-0462
* Origin: ILink: CFBBS | cfbbs.dtdns.net | 856-933-7096 (454:1/1)