map2kap - OziExplorer to OpenCPN

[cagney]

Here is my first version of a (semi) automatic tool for conversion of
OziExplorer charts to bsb charts.

map2kap .map-file picture-file [scale] [Sounding Units] [Soundings Datum]
[lat adj to wgs84 in seconds][long adj to wgs84 in seconds]
If an argument is left out and others follows put 'unknown' as a place holder.
It is alright to, for example, just give the scale and Soundings Unit and nothing else."

map2kap will produce usable charts with just the mapfile and picturefile as arguments, but it is worthwhile to open the chart picture and get some basic information:
The chart scale.
Sounding units - for example METERS or FATHOMS
Sounding Datum for example LAT,lowest astronomical tide.
Information is often available on the chart for applying corrections to the chart to agree with WGS84, Reverse the signs! This may be included in the map file, but not always.

The PP is handled by map2kap by averaging lat for mercs and long for tmercs.
Ozi separates REFs and PLYs, I have chosen to include all the ozi PLYs as REFs as well, as the geo referencing info is there.
Most picture formats are handled, but not always in the most efficient way, especially if the picture already is a tif.

An example

./map2kap.rb ROU3.map ROU3.jpg 30000 METERS MSL

Here I'm converting the Uruguayan chart ROU3. Chart scale is 1:30,000, soundings in meters and the datum for soundings is the mean sea level. There is no information available about the Geodetic Datum.When the script has finished, there is a kap file available with the same name as the map&picture file.

Dependencies: ruby, libtif, libbsb, ImageMagic
For this version of map2kap to work on windows you probably need cygwin installed.

I'm looking for Ozi charts that are Transverse Mercator, also chart that actually contains WGS84 corrections.

Feedback, as always, welcome

Thomas