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Rotation, time-span, and transparency for geotiffs and geotiffwrite

조회 수: 8(최근 30일)
D. Plotnick
D. Plotnick 2017년 2월 3일
So, I am playing around with exporting geotiff files to Google Earth (GE), and there are three capabilities I would like to explore. I cannot find any hard documentation on these and whether they are even possible. I am willing to look at other export formats other than geotiff (other image formats, exporting as a kml or kmz, etc.). The key is the following two requirements (1) Export from Matlab, and (2) import into Google Earth. Beyond that, any suggestions would be great.
(A) So my first question is whether it is possible to include a rotation in the geotiff. That capability does not seem to jive with the rectangular coordinate system of the associated GeographicCellsReference object used in the creation of the geotiff (essentially lat-long limits of the image). However, once the geotiff is imported into Google Earth itself you can find a 'Location' tab in the tiff properties menu which does allow rotation. So, is there a way to take a rectangular picture with a known center, rotation relative to Lat-Long, and size (in m,km or other) and export the rotated, scaled, and centered version of it to GE.
(B) Is there a way to export geo-located images to GE with transparent regions where there is no data? This is useful in general, plus I could use it in lieu of rotations. I could embed the rotated version of my image in a larger Lat-Long image with transparency. There seems to be only one post out there about this, which suggests adding a fourth Alpha channel to the RGB image. However, this only works when viewing the image in Matlab where you can specify that as the Alpha. Geotiffwrite (and GE) seem to interpret the 4-channel input as a CMYK image.
(C) A final capability is time-stamping or time-spanning of the image. Inside GE, you can use the time-span to make images change, or become visible/invisible based on a time slider. I want to embed a time-series of images in GE and this seems like the best way to do it (if you have other ideas, I'm all ears). In GE itself you can specify a time-span for a kml object, but I have no idea how to do it for a geotiff from matlab, or how to write a geotiff into a kmz file with associated time-span. Any ideas heartily welcomed.


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