Non-vectorized editing?

Posted by EMKLI on 10 December 2016 in English.

Hello there, fellow mappers!

I’ve started the first major approach to shape the coastline of north-eastern Norðurland. It’s not that easy, because I have a vast fjord scape in mind. I hinted that in one of my early mapping sessions with that “saber-tooth shape” of the coastline. Now, I finally want to map the whole thing out.

But there’s a problem: the details. When you take some minutes to closely inspect this (not so) random snippet of the norwegian coastline:

osm.org/#map=12/58.9968/10.0690

you’ll see that there are dozens of hundreds of islands, all in a very rough shape. A realistic rocky fjord coastline is suchlike rutted that it is almost impossible to map it out completely in this century, eypecially on such a length. What you see in the linked map is a coastline of ca. 30 km while the coastline which I intend to “fjordize” (from Frederikshöfn northwards, measured straight, without those cuts) is 3000 km - just mainland, not the huge islands… This means millons of small isles and thousands of narrow and wide cuts, fjords and lots of frustration…

I think that it’s definatly not feasible with vector editing. At least not alone and/or in a reasonable time frame. During all my mapping sessions, i realized that I really struggle with imitating natural landscape shapes on a reasonable level of detail with vectors. It would be so much easier to solve this with “paint style” editing - just paint an area with a pen tool and shape it with a pen tool of another color. For me, this feels more natural and more easy when it comes to coastline editing. Take a look at the map again and imagine the process: first, there is only the “white” mainland. Then, you paint the blue ocean - and then, you take a pen tool and start “cutting out” the islands and fjords, getting finer over time. This is so much easier than defining all those millions of vector nodes and move them in place, adding new ones to existing lines with those +es, always unintentionally moving the whole shape and getting ugly results…

Well, but we all know that OSM/OGF is all about vectors. However - is there a way to draw a two-color-map in Gimp/Krita/Photoshop/Paint.net/Pinta/KPaint/… and vectorize it afterwards to import it into JOSM? I know that there are some free vectorizers around in the Linux world, however I didn’t found them on the fly and of course, I have to figure out how to use them - well, i have to figure out anyway, but I thought, maybe one of you guys have already used one or have a different idea?

I really would appreciate your advice!

Discussion

Comment from Luciano on 10 December 2016 at 23:31

I am not an expert in Inkscape, but I know that application can do this - you can import e.g. a PNG or JPG format and save it as SVG. And then there are tools in JOSM to import SVG files.

But this is not within my technical abilities.

In fact, I’ve noticed that supposedly JOSM can import PDF directly - and many raster drawing programs allow “export as PDF.” I’ve never tried this, either.

What I do is somewhat more laborious, but it has worked well (with patience). I draw/paint things on paper, if I want that kind of detail, then I scan, upload as a temporary image in JOSM (using PicLayer plugin), and trace it. The “tracing” step adds a lot of work, but I find that manually vectorizing in this way can introduce space for additional creativity and increase map realism. The area where I’m most proud of my result using this draw-and-trace workflow is in the inland deltas of Ardisphere:

http://opengeofiction.net/#map=12/-23.8047/123.7481

Note that for tracing, the JOSM FastDraw plugin is indispensable.

Comment from EMKLI on 11 December 2016 at 12:00

I just successfully made an edit where the coastline is an imported raster graphics file. Thanks for the hints, Isleno as well as Paxtar! I’m so happy about this. Now it seems that I will get the coastline done in a few weeks instead of years. ;)

I’m going to write a small step-by-step tutorial for the wiki how it is done. Maybe some other people will profit from that.

Comment from EMKLI on 11 December 2016 at 12:01

Sorry, Luciano of course, not Isleno. :D By the way: your inland delta is really impressive!!!

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