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<DIV dir=ltr align=left><SPAN class=333022517-25022008><FONT face=Arial
color=#0000ff size=2>Bruce-</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=333022517-25022008><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=333022517-25022008><FONT face=Arial
color=#0000ff size=2>Again, I'm not sure how to convince you of this...
JP2 is inherently lossless just like GeoTIFF is; what arguments do you / would
you find persuaive to use GeoTIFF? (alternatively, what do you use now
that you trust?)</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=333022517-25022008><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=333022517-25022008><FONT face=Arial
color=#0000ff size=2>[feel free to take this to private email, this is probably
a bit esoteric for the rest of the OSGeo crowd]</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=333022517-25022008><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=333022517-25022008><FONT face=Arial
color=#0000ff size=2>-mpg</FONT></SPAN></DIV>
<DIV> </DIV><BR>
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<FONT face=Tahoma size=2><B>From:</B> discuss-bounces@lists.osgeo.org
[mailto:discuss-bounces@lists.osgeo.org] <B>On Behalf Of
</B>Bruce.Bannerman@dpi.vic.gov.au<BR><B>Sent:</B> Saturday, February 23, 2008
2:19 PM<BR><B>To:</B> OSGeo Discussions<BR><B>Subject:</B> RE: [OSGeo-Discuss]
'lossless' JPEG2000<BR></FONT><BR></DIV>
<DIV></DIV><BR><FONT face=sans-serif size=2>IMO:</FONT> <BR><BR><BR><FONT
face=sans-serif size=2>Michael,</FONT> <BR><BR><FONT face=sans-serif size=2>My
concern as a custodian of significant image resources is to ensure that the
integrity of this data is protected and available for future analytical use by
ourselves and by the public.</FONT> <BR><BR><FONT face=sans-serif size=2>As an
example, to conduct multi-temporal analysis of 'imagery' to help understand
big picture issues such as climate change.</FONT> <BR><BR><BR><BR><BR><FONT
face=sans-serif size=2>I understand that wavelet compressions such as MrSid
and ecw are lossy compressions and JPEG 2000 can be 'lossless', or as often
occurs, lossy.</FONT> <BR><BR><BR><BR><FONT face=sans-serif size=2>I'm
currently seeing proposals to the effect:</FONT> <BR><BR><FONT face=sans-serif
size=2>- wrt imagery, most people only want to look at pretty pictures</FONT>
<BR><BR><FONT face=sans-serif size=2>- therefore we'll compress our imagery
via wavelet compression and save a lot of disk space and ongoing SAN costs by
backing up the source imagery to tape. Noone uses it anyway.</FONT>
<BR><BR><BR><BR><FONT face=sans-serif size=2>I've been around long enough to
expect problems from tape backups, and to not expect my data to be there when
I request a restore.</FONT> <BR><BR><FONT face=sans-serif size=2>I can also
see an increasing need for image analysis for big picture issues such as
climate change and water shortage (in Australia).</FONT> <BR><BR><BR><FONT
face=sans-serif size=2>Therefore, naiave as it is, I want to be 'convinced'
that our data is protected for future use before agreeing to such potentially
irreversible proposals.</FONT> <BR><BR><BR><BR><FONT face=sans-serif
size=2>Bruce</FONT> <BR><BR><BR><BR><BR><FONT
size=2><TT>discuss-bounces@lists.osgeo.org wrote on 24/02/2008 08:44:25
AM:<BR><BR>> Bruce-</TT></FONT> <BR><FONT size=2><TT>>
</TT></FONT> <BR><FONT size=2><TT>> It is not clear to me what sort
of "study" you would need to <BR>> convince you, as the ISO standard for
encoding data into the <BR>> JPEG-2000 file format is by construction
mathematically and <BR>> numerically lossless process. (Indeed,
"compression", i.e. throwing<BR>> away bits so as to further reduce storage
requirements, is actually <BR>> not defined within the scope of the
standard.)</TT></FONT> <BR><FONT size=2><TT>> </TT></FONT> <BR><FONT
size=2><TT>> -mpg</TT></FONT> <BR><FONT size=2><TT>> </TT></FONT>
<BR><FONT size=2><TT><BR></TT></FONT>
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