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notes.txt
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notes.txt
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height data: kartverket, hoydedata.no
format:
sections are exported as GeoTIFF, and for each tile x there are the following files:
x.tif the heightmap itself
x.tif.ovr overview (3 thumbnails of differing size on separate layers)
x.tif.aux.xml geodata and statistics, eg. min and max height, histogram etc.
x.tfw world file, describes the location, scale and rotation
x.sos SOSI-format file, metadata
the value of a pixel seems to correspond 1:1 to the height in meters.
"I was able to find an alternative Java imaging library called Apache Commons Imaging.
It is a pure-Java library that consists of a single small JAR file.
It also supports both reading and writing of the TIFF file format and
it has built-in support for GeoTIFF tags. It appears to handle all of
the common compression formats as well."
-> doesnt seem to support 32bit floating point gamma.
alternative:
https://dzone.com/articles/access-information-geotiff
-> geotools.org, gt-geotiff
-> didnt work with my tiff files.... threw DataSourceException
JAI works, but:
maven fails to resolve JAI, _unless_ I add geotools repo and install it.
it seems to pull JAI in as a dependency.
-> yes indeed, http://download.osgeo.org/webdav/geotools has JAI
// step 0:
// select sub-area of world such that dimensions are divisible by
// data resolution, ie. samples/m^2
// and also divisible by 16 (chunk size)
// step 1:
// area: rectangle2d.float, pixel: point -> global_location: point3d
// step 2:
// global_location: point3d -> local_location: point3d, chunk: point2d
//System.out.println(worldSections.size());