It is a bit special in the sense that
- It's a square projection (Anaximandre)
- It is in several colors.
We now have the possibility to just make a fax transparent, without changing the black to another color (which is a possibility that still remains).
Having the colored fax transparent allows as usual superimposition with other data, like GRIBs or charts.
We can produce a rendering like this:
Some improvements in the image processing have been done too, regarding the transparency, and the sharp and blur. Looks much nicer. I had the idea of doing it by looking at what OpenCPN was doing for their charts rendering, which is much nicer than Maptech, based on the same data files.