Charts

[cagney]

Leo, nice to see you found the OpenCPN forum.

OpenCPN understands pure S57, so perhaps it will be possible to read OSeaM charts with minor modifications. This would be the best solution.
Failing that we can convert png pictures to .kap charts. This chart thread has grown very long .... but in here there is instructions for what to do. There is no need to go via SeaClear/MapCal.

One way is to create a geo-referencing text file for each png chart picture. It doesn't matter much what format the text file is using, but for example 'yaml' would be nice.
The minimum content must be something like this:

Name: Whatever
Scale: 50000
Projection: Mercator (note OpenCPN handles only Mercator, for now)
PP: "Lat at which scale is valid"
Chart Datum: WGS 84 (preferable)
Datum for soundings : Lowest Astronomical Tide (for example)
Units for sounding : meters (or feet, or fathoms)
+
the four corner of the map in this format
pixel width, pixel height, lat, long

With this information it is easy to script a utility tool for conversion to .kap files.

Thomas

[stow]

Searching Internet I found a bunch of charts (*.jpg) on Venezuelan Hydrographic Office website. Here is link to the web adresses: http://dl.dropbox.com/u/3490420/Vene...20maps_jpg.zip
Another KapGen needed?

and additionally link to Colombian ENC http://www.cioh.org.co/index.php?opt...id=176&Itemid=

enjoy

[oem]

Originally Posted by Leo12305

to all

Hallo Friends we started here in Germany the OpenSeaMap projct. This project is a part of OenStreetMap. We are going to produce an open source free seachart. If you are interested look to our website.

OpenSeaMap - Start

We hope that we find many people who can help tagging Seamarks.

Greating from Germany
leo

I have seen OPenSeaMap before, but I did consider the initiative 'dead'. This time I tried to make 'Holtserhage' at lat 55.69845 lon 9.6681 with the online OpenSeaMap editor, but I didn't succeed.

However I think that OpenSeaMap is a possible answer on all initiatives to create free marine charts. It's S57-format (should possibly be oriented towards S100(102?)) and it should be possible to download in S57 and/or raster format (as above). Just like NOAA?

But, am I right, a lot of programming needs to be done to be able to collect information from people like me?

How can somebody like me help? I could easily supply gps-positions and types of all seamarks around Denmark. In a GPX-file e.g.?

[cagney]

Sorry, I have to come with a PITA message.
The copyright notice on the Venezuelan charts makes it utterly clear that we cannot treat these charts the same way as the NZ charts.
Read for yourself. Hugo has to give us permission first.

As far as I can see the Colombian chart seems OK. Just stated as "available for download" (thanks to Google translation).

Dacust: Another one for your collection.

Thanks "stow" for your research.

Thomas

[Leo12305]

Originally Posted by cagney

Leo, nice to see you found the OpenCPN forum.

OpenCPN understands pure S57, so perhaps it will be possible to read OSeaM charts with minor modifications. This would be the best solution.
Failing that we can convert png pictures to .kap charts. This chart thread has grown very long .... but in here there is instructions for what to do. There is no need to go via SeaClear/MapCal.

One way is to create a geo-referencing text file for each png chart picture. It doesn't matter much what format the text file is using, but for example 'yaml' would be nice.
The minimum content must be something like this:

With this information it is easy to script a utility tool for conversion to .kap files.

Thomas

The OSeaM Datas exit in a small modification of S-57. The differens is that we use normal long words and S-57 use 6 charater long words. The easyest way for you is that you lookin our xapi. For questions around this part of OSeaM mail to ohannemann@opensource-werkstatt-stubben.org.
I work for the user of bitmap programs and try to find konverting scripts.
leo

[sinbad7]

All our Charts normaly are vector Charts. Nearly s-57 but not 100%. OSeaM has 18 Zoom steps. From each of 18 steps we can produce bitmap(png) Charts for use with OziExplorer. These can we directly convert to Seaclear WCI format. If you do this way there is no chartdir created. So your way with mc2bsbh is not going. I look for a way to create BSB/KAP Charts direct.
leo

I am not sure I follow your conversion attempt. You have to use the MapCal II calibration facility to produce the required header file used in the conversion process to the final .kap file. The original bitmap is converted to both .png and .tif (127 col.)
Converting to SeaClear format is only good for SeaClear users.

I have converted two charts to .kap so far but I am somewhat puzzled by the appearance of grids during the conversion process? No grids are visible at the time of the screen capture of the OpenSeaMap. Have a look...

I think the OpenSeaMap could be a valuable addition to the already available formats in OpenCPN,even at this stage in the development. In the spirit of other Open programs,it would develop through the joint knowledge and contribution from the users.

[Leo12305]

Originally Posted by sinbad7

I am not sure I follow your conversion attempt. You have to use the MapCal II calibration facility to produce the required header file used in the conversion process to the final .kap file. The original bitmap is converted to both .png and .tif (127 col.)
Converting to SeaClear format is only good for SeaClear users.

I have converted two charts to .kap so far but I am somewhat puzzled by the appearance of grids during the conversion process? No grids are visible at the time of the screen capture of the OpenSeaMap. Have a look...

I think the OpenSeaMap could be a valuable addition to the already available formats in OpenCPN,even at this stage in the development. In the spirit of other Open programs,it would develop through the joint knowledge and contribution from the users.

OpenSeaMap will offer Charts for many Chartplotters and PC-programs.So we start with free Software SeaClearII. It is impossible that you have everytime all Chart on board. So we will produce Charts for areas. this must going with an automatic with a minimum of manuel work.

Now I will try explain you the problem with mc2bsbh. Mc2bsbh need for working a the seaclear chartcal.dir file. This file exist only when you make the geographic refference with MapCal.
I get a geographic referenced File (Chartname.map). This file can we directly convert with MapCal to a WCI Chartfile for use in SeaClear without manuel doing . When we do this, no Chartcal.Dir exist.

Next : You make this file from the England Channel and you see the grid this is the grid from the tiles (each tile.png is 256 to 256 pixel big). There must be a mistake by make the chart.
leo

[GPS-Marco]

Originally Posted by Leo12305

The OSeaM Datas exit in a small modification of S-57. The differens is that we use normal long words and S-57 use 6 charater long words. The easyest way for you is that you lookin our xapi. For questions around this part of OSeaM mail to ohannemann@opensource-werkstatt-stubben.org.
I work for the user of bitmap programs and try to find konverting scripts.
leo

Hi Leo,

What is the effort to convert the OseaMap format to standard S57? If you are able to make such conversion, OpenCPN could natively load the OpenSeaMap vector maps (more or less..).

Ciao, Marco.

[sinbad7]

Leo # 337

Converting ALL charts to each specific Nav Prog will be quite a job and very time consuming. It would be far more practical to make your S-57 compatible with the standard for use in ALL S-57 compatible nav progs.
The conversion job would be better left to each users requirement and area and could be stored in a common,free database.

I don't know why you mention mc2bsbh,I am using the tif2bsbh to do my .kap conversion which works perfectly and is used exclusively to produce .kap files compatible with OpenCPN,although it also work up to a point with f.ex Shipplotter.

How are you producing the geographic referenced file 'Chartname.map' for use with SeaClear? You must be using MapCal?

The grid/tiling I experienced using OpenSeaMap was caused by my Opera browser it seems. It worked perfectly with Mozilla..

[sinbad7]

Some charts come out better than others. The port of Rotterdam has a lot of detail and contrasts. Showing the real-time AIS trafic at 20:00 UTC.

[Leo12305]

Hallo Sinbad7
It possible that charts looks different. We have a open system. Everybody can change the look. You have several rendering programs each prduce a other view.
leo12305

[sinbad7]

Hallo Sinbad7
It possible that charts looks different. We have a open system. Everybody can change the look. You have several rendering programs each prduce a other view.
leo12305

Very interesting Leo..I understand.. I thought all the map areas were similar.
I notice ports in the far North of Norway are not very detailed.

How can the users add information other than the sea markers? Many places are missing lighthouses,marina indicators etc. OpenCPN has many ways to add info in the individual users charts.

Here is a FINAL OpenSeaMap conversion of the port of Antwerp with real-time AIS traffic at 22:00 today. I will await further development of OpenSeaMap with respect to full S-57 compatibility with OpenCPN as well as real depth info.

Thanks for your great efforts making free mapping info available to the yachting fraternity.

[sinbad7]

Leo...

One way to solve the missing depth feature in OpenSeaMap is to use the overlay method,used by cartographers to merge street map features with navigation charts, keeping one of them in an adjustable transparent mode as you can see from the attachments. Perhaps a transparent C-Map can be overlaid the OpenSeaMap?

[idpnd]

Originally Posted by sinbad7

Perhaps a transparent C-Map can be overlaid the OpenSeaMap?

The whole point of Openseamap is to have free, publicly owned charts. If the depth features are lacking, you may wish to edit the map to enter the depth values.

Oddly enough, I suppose the content would have to be manually copied from existing commercial charts (which were generated with taxpayer money in the first place) for this not to constitute copyright breach.

Perhaps there could be a "semi-automated" mechanism for extracting the C-MAP data onto Openseamap? Anyone?

[LeaseOnLife]

When looking at gribs on top of BSB charts, I would like to have a large scale, black and white, world map with enough detail to see, for example, the Caribbean islands.

If one has a chart like this available to share, please PM me for my email address.

Dirk