Converting from OCAD

There is yet no simple way to convert from OCAD to OSM. However, exporting to Shapefiles in OCAD, you should be able to export you map to OSM format but I have not had the possibility to try. Therefore there is no table for converting OCAD objects to COMO map feature tags. The projection from plane coordinates to lat/long might be another problem.

Exporting Shapefile

The easiest is to export your OCAD map as a shapefile and then convert that to the OSM file format. Shapefile export is only available in the professional edition of OCAD. If you only have the standard edition, you have to export as dxf file and then convert that to a shapefile, see further down.

By exporting to shapefile you should be able to get your features from OCAD converted to the corresponding in COMO (not tested). You will have to configure how key and values shall be translated. Please read at OSM wiki:  shp2osm possibilities

Here is also described how you transform your projection. This might be a bit of problem if the shapefile exportet from OCAD doesn't include correct information.

Exporting dxf file

If you don't have OCAD Professional but only standard edition, you will have to export your map to dxf and then convert it to a shapefile. Note, you WILL lose information (what I can see, you don't get any information about types of objects).

Use Grass to convert to shapefiles:  Converting dxf to shapefile

Old map as background

JOSM#Backgroundimages

Converting to OCAD

Not recommended. Feel free to try: