Re: Quicktime movies

From: Steve G. Hilliard (steve@habanero.cb.uga.edu)
Date: Thu Oct 07 1999 - 17:47:04 EST


I'm puzzled by the fact that Tony bothered to quote me, and then cut off
my final paragraph noting the lossy compression problem w/ jpegs.  At any
rate, I certainly agree with he and Derek--I hadn't considered the fact 
that jpegs have to be decompressed on the fly--not the best approach.

take care,
Steve

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Steve G. Hilliard                 (706) 542-9474
University of Georgia Cell Analysis Facility
flowman@uga.edu	     URL:  http://floweb.cb.uga.edu/Floweb/
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

On Thu, 7 Oct 1999, Tony Schountz wrote:

> "Steve G. Hilliard" wrote:
> 
> > While I'm no expert on imaging or QT, I would suggest converting each to a
> > jpeg, since this format presents photos so well, and produces quite
> > compact files.  If you have any control over jpeg quality you might want
> > to do a trial run at different settings, because jpegs can often be
> > compressed at 50% quality and still look good enough for the web.  I
> > would think the same would be true for movies.  (I'm surprised it lets you
> > produce QT's from tiffs, because they're huge!  Streaming tiffs would take
> > a LOT of computing power.  I'd go for a Linux beowulf cluster ;-)
> 
> One word of caution for this approach. JPEG is a compression algorithm that
> loses pixel information each time a file is saved. Standard TIFF does not use
> compression and thus no pixel information is lost. Consequently, TIFF files are
> very large compared to JPEG. In the final analysis, TIFF provides a better, but
> larger image. If you want to string together images as a QuickTime movie,
> compression of each image is not necessary (and may result in image
> deterioration) as QuickTime files are compressed when made. On the Mac platform,
> the file formats of choice (IMO) for storing still images for incorporation into
> a QuickTime movie are PICT and Photoshop native. No pixel information is lost
> and when they are incorporated into a QuickTime movie by QuickTime editing
> software, the final movie is compressed to minimize file size.
> 
> Just my $0.02 worth.
> 
> --
> Tony Schountz, Ph.D.
> Department of Biological Sciences
> Mesa State College
> mailto:tschount@mesastate.edu
> 
> 



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