Wow!!!
That’s GREAT news!
Hopefully, this is only the first in many donations.
There are several ways of doing it.
I think the easiest is to have it as a background, e.g. in Potlatch2.
Need to cut the whole image into 256x256 pixels squares, and align them.
The easiest is to decide on a zoom level, say 14, and look at some key tiles, and align according to them.
Then we need to name the tiles according to the standard (zoom level, x, y)
Actually, only one dimension. The other 2 are directories, or using underscores and put it all in the same directory.
And then it would be easy to have as a custom background.
I can do the graphical cutting. Will not take that much time I think.
Maybe the source image needs to be zoomed before cutting, so you will have a higher zoom level?
Another option is to set up a WMS server. It’s really easy with Geoserver, takes 10 minutes and works out of the box. I have already done this on my local machine, unfortunately I am behind a firewall so it’s no good for others.
Then you would point Potlatch to something like “http://localhost:8080/geoserver/wms?”
I can try and write some script that creates these tiles.
This script would be reusable if/when we get an updated version of this file.
I know this file change once in a while, when municipalities are formed or merged one into another.
If jpg/jgw combination is the standard, then we could use this script in future imports as well.
My biggest problem right now is: what is the naming scheme for tiles which Potlatch understands?
I managed to produce beautiful tiles which can be overlayed on Google Maps, but not in Potlatch.
Click on the arrow next to “Background”
Click on the “Edit…” button. You’ll get a “Background imagery” popup window.
Click on “Add” (bottom right), a new line will be added, and edit it as follows:
I have played a little with automatic vectorising before and I decided to try my old vectoriser on the .jpg file with the borders. The results are very bad, probably useless, but if you’re curious, I have put up some files to look at:
These results are so bad because the parameters are adjusted for a different task (I had building outlines at very very high resolution, so the vectoriser ignores short segments, and tries to find right angles everywhere, even if there aren’t any). I will play with the parameters a little tomorrow, today I spent all the time trying to get the EPSG:2039 projection right.
Dimka, could you ask MOIN for an image file without the names?
Sometimes the names are in the way, like in Abu Gosh / Kiryat Yearim.
We could trace on the nameless file, and use the names from the named file, switching between the2 overlayes.
The nameless file could be used by balrog-kun to get better results.
I now basically removed all of the building-related postprocessing and now the results are a little better, I don’t think it’s possible to do this better except for manual tracing.
Note that the blue lines have a width of 7 pixels, so they are polygons and it’s difficult to calculate only the centrelines (I think it’s impossible).
When the administrative borders run along streams (e.g. Beit Gamliel). What is more accurate, the borders based on the raster image you got, or the natural borders. And if the latter is true, should we correct them?
AFAIK, officially, the raster image is more accurate.
When streams change course, it takes time for the MOIN to do new surveys and update the administrative borders. If at all…
