Partial BigTiff support for Cloud Optimized GeoTiff (Work in progress) #80
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I have started to add a support of BigTiff in UTIF.js, this could be very useful for Cloud Optimized GeoTiff (https://www.cogeo.org/). These files could be very large but you never need to load the whole image. It's possible to analyze the IFDs informations by reading only the first few Ko and then, to request only specific parts of the file for specific tiles (in full resolution or in overviews).
There are some differences in the file structure for BigTIFF (https://www.awaresystems.be/imaging/tiff/bigtiff.html) but nothing really complex. In this PR, there are the minimalist changes for my immediate needs (https://github.com/gmaillet/itowns/tree/cog-source) but it doesn't manage decoding of all TiffTag types and it doesn't manage BigTiff in encode and encodeImage.
What do you think about it?
Have you a Tiff dataset with all possible tiffTag and encoding options to help me to test and finalized my modifications?