Hi Taylor, I'm just lurking on the mailing list myself.
I had a look at the code changes, as this is one of the formats I'm interested in, and one point springs out at me: const double PI = atan(1.0) * 4; I find this line potentially a confusing way to define PI, particularly when you combine it with (PI/180) later. Personally I would use M_PI. Regards Damian On 27 February 2017 at 11:55, Taylor Alexander Brown < browt...@oregonstate.edu> wrote: > Greetings GDAL Community, > > I am developing an application [0] to process georeferenced raster > hyperspectral imagery in ENVI format from NASA's Airborne > Visual/Infrared Imaging Spectrometer (AVIRIS) [1]. > > The `map info` section of the header files contain an undocumented [2] > rotation field which is currently ignored by GDAL. As a result, the > image is rotated incorrectly when I process it with `gdalwarp` or the > GDAL Python API. Furthermore, the image is scaled incorrectly when I try > to override the geotransform. > > I documented my experiences on the GIS Stack Exchange [3]. It has > previously been described on the GDAL mailing list [4] and bug tracker > [5]. I believe this issue also affects ASTER imagery [6][7]. > > I have implemented a fix based off of branch `tags/2.1.3` and shared my > code on GitHub [8]. It reads the `units` and `rotation` parameter from > the `map info` section and uses these to calculate the geotransform. The > scaling was off because the code expected the `units` parameter to be > the last element in the list, when in my case it was the second to last. > You can verify this behavior with the single-band image I have been > using for testing [9]. > > You are welcome to evaluate my code and contribute it back to the > library. I am a novice at both GDAL and GIS, so there may well be > problems. I would be willing to submit a pull request against your > GitHub mirror if desired. > > > Peace, > > Taylor Alexander Brown > > > [0] https://github.com/capstone-coal/pycoal > [1] https://aviris.jpl.nasa.gov/ > [2] http://www.harrisgeospatial.com/docs/enviheaderfiles.html > [3] > http://gis.stackexchange.com/questions/229952/rotate-envi- > hyperspectral-imagery-with-gdal > [4] https://lists.osgeo.org/pipermail/gdal-dev/2013-January/035146.html > [5] https://trac.osgeo.org/gdal/ticket/1778 > [6] http://yceo.yale.edu/opening-aster-files-envi > [7] http://yceo.yale.edu/faq-page#t2n504 > [8] > https://github.com/OSGeo/gdal/compare/tags/2.1.3...browtayl: > fix-envi-rotation?expand=1 > [9] https://drive.google.com/open?id=0BxysdOuBmaIGalY5dVhCa1Y5M0k > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > https://lists.osgeo.org/mailman/listinfo/gdal-dev
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