[gdal-dev] Re: gdal_merge.py stitched output image intermittent projection info loss

[Dori]

Forgot to specify: the programs run hourly and they run OK at all hours but
some. On some days they run OK at all times but 0,3,6,9,18,21,23 UTC(GMT)
and on some days they also failed at 12 and 15 UTC.  However, they run OK
throughout the rest of the hours.  This is why I am convinced this must be
something happening at the times the programs create the output images
without Projection info.

ImageMagick and openEV display all images even the ones not been displayed
by the 3rd party software also used to create the input images. In all cases
those are grey scaled satellite pictures i.e. not very big images.

Thanks again for any help


On Tue, Mar 17, 2009 at 1:21 PM, Dori <izzybitsie at gmail.com> wrote:

> Hi,
> I have used gdal_merge.py to stitch geotiff images created with a 3rd party
> software for a couple of years now.
> These programs were moved to new hosts a while ago and from there on,
> although the stitching works the output image seems to loose the projection
> information when they are created at certain times of day but not at some
> other times.
> When the projection info is lost, the image cannot be viewed in the 3rd
> party software used to create the images been stitched, making it useless.
> However, all images can be displayed with ImageMagick or openEV.
>
> Is there any command I could use to make sure the projection information is
> stored in the output image at all times?
>
> I think my intermittent problem might be cause by some memory shortage on
> the new hosts at certain times of the day .  The input images are not very
> big ~4 Mb each and there is 16 of them. The output images are not that huge
> either:~22Mb
> If this is true then, there is not much I could do to resolve my immediate
> problems.
> I am no expert so, I may be missing the real cause of the problem.
>
> What makes it hard to guess what it is is the fact that there are no errors
> logged as the program work all the time.
>
>
>
> Thanks
>
>
> This is the projection info for output map when cannot be viewed using 3rd
> party soft.:
>
> Size is 7479, 3033^M
> Coordinate System is:^M
> LOCAL_CS["unnamed",^M
>     UNIT["metre",1,^M
>         AUTHORITY["EPSG","9001"]]]^M
> Origin = (-179.999899999999997,73.000000000000000)^M
> Pixel Size = (0.048132577673166,-0.048139266469396)^M
> Metadata:^M
>   AREA_OR_POINT=Area^M
> Image Structure Metadata:^M
>
>
>
> This is the projection info for output image when it CAN be viewed using
> 3rd party software:
> Size is 2400, 1800^M
> Coordinate System is:^M
> GEOGCS["unnamed",^M
>     DATUM["WGS_1984",^M
>         SPHEROID["WGS 84",6378137,298.2572235629972,^M
>             AUTHORITY["EPSG","7030"]],^M
>         AUTHORITY["EPSG","6326"]],^M
>     PRIMEM["Greenwich",0],^M
>     UNIT[,0.0174532925199433]]^M
>
>
> This is the projection info for the input images:
> Coordinate System is:
> GEOGCS["unnamed",
>     DATUM["WGS_1984",
>         SPHEROID["WGS 84",6378137,298.2572235629972,
>             AUTHORITY["EPSG","7030"]],
>         AUTHORITY["EPSG","6326"]],
>     PRIMEM["Greenwich",0],
>     UNIT[,0.0174532925199433]]
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/gdal-dev/attachments/20090317/6100943a/attachment-0001.html