[Gdal-dev] GDAL, JPIP and OpenEV

[Frank Warmerdam]

On 1/11/06, Norman Barker <nbarker at rsinc.com> wrote:
> Hi,
>
> just by chance when I was using OpenEV I noticed that when displaying ECW or Jpeg2000 it seems to have a progressive quality display.
>
> If OpenEV does implement progressive display for wavelet based images (with quality and resolution layers) how hard would it be for OpenEV to take its data from a JPIP server?
>
> I have a JPIP image server, and will have a go with OpenEV and GDAL if someone can confirm that I haven't witnessed a trick of the eye!!

Norman,

I believe it was a trick of the eye.  In particular as
you zoom in OpenEV will interpolate up the lower
resolution data till it has a chance to reload higher
resolution data.  So you are seeing full res data filled
in over time, but it isn't due to use of progressive display
from the wavelet information.  The same thing happens
with uncompressed formats.

I have had a little success in the past with GDAL
and JPIP via the JP2KAK driver but also lots of
unexplained failures.  Also, the JPIP in GDAL is only
supported on windows.  But I think you should be able to
use a jpip url with gdal (or openev) on win32 currently.

Best regards,
--
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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