[gdal-dev] georeferencing raster data using vector polygon

[Roger André]

Hi Simen,

Ok, here is how to implement the suggestion I gave, which was to create a
new worldfile and shift the image so that it fit the footprint vector
better.

1. Use gdal_edit.py with the "-unsetgt" option to remove the georeferencing
from the .tif
2. Then copy the attached .tfw file into the same dir as the .tif and view
it in relation to the KML footprint.
3.  You can tweak the alignment further by modifiying the bottom 2
coordinate values in the .tfw file.

Why do I advocate this method over warping the image using GCP's or QGis?
Because those are "lossy" processes.  In other words, the warping will
force a re-write of the pixel values using some sort of interpolation.  You
might still want to do that at the very end, like if you need  perfect
point-to-point matching against the footprint corners, but I still would
shift the image first.

Hope this helps,

Roger

On Wed, Nov 19, 2014 at 1:16 AM, Simen Langseth <simlangen at gmail.com> wrote:

>  I wanted to georeference the raster image in UTM coordinates into the
> boundry of red polygon with geographic coordinate system.
>
>
> https://drive.google.com/file/d/0B2RqG9tSAAIUc3J5ZDN6V01IcG8/view?usp=sharing
>
> I tried as follows:
>
> gdalwarp,-t_srs wgs84 -srcnodata 0 -dstnodata 0 -r near -te -96.75234
> 54.93479 -92.90071 56.91041 i
>
> What parameters should I provide for that?
>
> _______________________________________________
> gdal-dev mailing list
> gdal-dev at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/gdal-dev
>
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