[gdal-dev] Fwd: gdal_merge.py - Missing images - sans attachment

[Jay L.]

I got this working this morning.  Again, I simply need to explore the
documentation better!  My issue was not with format or projection, but with
image size.  My final mosaic kept hitting the 3.7GB mark, regardless of
whether I used a .vrt, a GTiff, or worked with gdalwarp.

Reading the GTiff driver documentation, I needed to set BigTiff to yes.

Thanks all who responded.  Using a vrt definitely sped the process as I no
longer needed to batch translate from IMG to tif.



On Fri, Oct 7, 2011 at 6:59 PM, Chaitanya kumar CH
<chaitanya.ch at gmail.com>wrote:

> Jay,
>
> The gdal_merge script needs the images to match in the coordinate system
> and the number of bands.
>
> One likely problem is could be different data types. Provide the gdalinfo
> outputs of the images.
>
> Before you try that, use the gdalbuildvrt program to create a vrt file and
> then gdal_translate to convert the vrt file into a single image. The result
> is usually the same.
>
>
> On Fri, Oct 7, 2011 at 9:12 PM, Jay L. <jzl5325 at psu.edu> wrote:
>
>> Sent with an example attachment, which is awaiting approval.  Here is the
>> mail without attachement.
>>
>>
>>  I have 8 large Gtiffs which I am trying to mosaic.  Tiffs were created
>> from .IMG files downloaded from PDS.  I converted to tif using:
>>
>>         gdal_translate -of GTiff -scale -co "TILED=YES" -co
>> "COMPRESS=JPEG" <input>
>>
>> The format conversion is working without a problem.  Gdalinfo is reporting
>> the correct NDV and projection information.  Viewing each tif also returns
>> the expected raster iamge.  So far, so good.
>>
>>
>> I then use:
>>
>>         gdal_merge.py -o wacmos.tif -of GTiff -v --optfile tiff_list.txt
>>
>>
>> Six of the eight tiles are added to the mosaic correctly.  Varying the
>> order in the list, or using *.tif does not change the output.  It is always
>> the same two images which are missing.  Watching the verbose output, it
>> looks like the images are mosaicing correctly.  What would cause these
>> images to be merged as totally black tiles?
>>
>>
>> Thanks for any insight,
>> Jay
>>
>>
>>
>>
>>
>> _______________________________________________
>> gdal-dev mailing list
>> gdal-dev at lists.osgeo.org
>> http://lists.osgeo.org/mailman/listinfo/gdal-dev
>>
>
>
>
> --
> Best regards,
> Chaitanya kumar CH.
>
> +91-9494447584
> 17.2416N 80.1426E
>
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