map2kap - OziExplorer to OpenCPN

[TechNeck]

Thanks Cagney & Seagull for helping. Here is link to log-file:

http://www.filedropper.com/opencpnlog

The charts are converted from working Ozi-files which I have used for some years. They are official Finnish navigational maps and are perfectly calibrated even when compared to other maps. I have 100% trust on these Ozi charts. Only quilting in OpenCPN brings these problems.

In Ozi I can make and have manually made the chart changing area so that chart is changed to next chart before the chart border is reached so I have allways vision of what is coming up. So quilting is made differently in Ozi compared to OpenCPN. I converted working Ozi calibrated charts to OpenCPN format, is this a problem and I shold use "clean" calibrated Ozi maps w/o chart change area?

FINLANDHAYFORD vs. FINLAND HAYFORD; which program to use to change this line?

[TechNeck]

I re-made two charts with imgkap and changed "FINLANDHAYFORD" to "FINLAND HAYFORD" and removed position digitals to reasonable number (5). No help, unfortunately. Quilting still changes the chart positioning. I will still test removing the Ozi based chart size limitations & try again.

[HappySeagull]

for helping

trying to help in my instance.I am just making noises in case they help. Cagney is your best hope!..but I will see what other kap charts I can dig up in Finland to quilt with yours in Oto experience your problem the way you do.
BUT:
First off, I would definitely check what FINLAND HAYFORD is versus WGS 84.And double-check that these charts ARE ACTUALLY CALIBRATED as FINLAND HAYFORD versus wgs84. that seems a huge nuisance in everything you do here. I would personally calibrate the charts to wgs84 if they need it, otherwise just change GD to WGS84. see below "editing?"

shold use "clean" calibrated Ozi maps w/o chart change area?

I am not sure what "chart-change area" is...But I don't think you need it in opencpnwith these as I said, but when you can make a few that work correctly, you will know better.
What version of Ozi do you have? I have a very old one-it doesn't exactly "quilt" charts-it moves to the next automatically as the gps position changes.

In O, "quilting" is about Scale too -roughly speaking the "best" scale with readable detail overlays floats on less detailed charts WHEN it will fill most of the screen. ..that is, when the screen is "zoomed in"

editing?

FINLANDHAYFORD vs. FINLAND HAYFORD; which program to use to change this line?

well, my opinion above aside, it might be easier to change the name in your OZI!! but in the kap file, a proper "hex editor" is the best (I have "Frhed" or "HXD").... but I mostly just use "Notepad++" being sure to keep the "text encoding" the same. (ANSI works) and then I drag the edited file onto "bsbfix.exe".
as to "map" files I can just use notepad++ but again-I check the "encoding" the same.

I will still test removing the Ozi based chart size limitations

I wouldn't bother. M708 is a very nice image ! 9918 by 7272 pixels is big enough !

[HappySeagull]

Best I can do with your original and what I have thereabouts. It still works fine for me.


and I made another kap copy in imgkap...a little more involved this time. I extracted the image as a png then rebuilt it as kap by using two diagonal marks made in opencpn (quilting is off to see the corners of the entire image)

By the way, This was a bit odd.Trying to make Marks at corners (quilting off) at the pixel scale was a moving target - They kept shifting a tiny bit...but the new chart worked fine.

[HappySeagull]

and comparing log files, mine to yours
I get:

Line 974: 9:25:30 AM: Loading chart data for ..\..\..\..\CHARTS\CHARTS_MODIFIED_USED\M708.kap
Line 975: 9:25:30 AM: Adding chart file: ..\..\..\..\CHARTS\CHARTS_MODIFIED_USED\M708.kap
Line 1017: 9:26:04 AM: Initializing Chart ..\..\..\..\CHARTS\CHARTS_MODIFIED_USED\M708.kap

and that's all, which is good.
From your log, at first you are also good with M708 it " initialises" ...until a chart named "D Turunmaa.kap" shows up in your log "D Turunmaa.kap is 0.00512334
nominal pixel error is: 30.1768...." -after that M708 won't work
and also some other bad ones...

"Warning: Skew override on chart D:\Users\Markus\Veneily\Kartat\MeriCDOpenCPN\C Ahvenanmaa\S732_03.kap is 36.2211 degrees" and also "Södertälje kanal b (1987).kap is 22.6268 degrees"

this is bad:
I had this too- and my chart was not in any way skewed and Skew was 0 in the header-finally,I had to rebuild it from scratch, even to extrapolating and resizing the image

there's some are SWEDISH Grid-you'll have to fiddle with those too...

[cagney]

I have access to a few of these old Finnish charts, also converted with map2kap. Still they are of a different origin, with different calibration.
After some testing I think that TechNeck has found a problem with quilting in O.
Thank you!
My testing indicates that.....
*When quilting, O uses WGS84, and don't use the GD value. In Single chart mode, GD is ofcourse used. I'll enter this in the tracker.
* Some Finland Hayford charts actually have a WGS84 printed grid. When O applies the Finland Hayford correction, things get bad. Compare to NAD27 and old Canadian Raster charts.
* The "Finland Hayford" correction in OpenCPN is suspect. I find different values mentioned on the net. There are 4(or 6 ?) zones for this datum, with different corrections. Once again compare with NAD27. O has no way to handle this. More here Finnish coordinate systems
* All this is a legacy problem as all Finish charts after 2005 are WGS84.

Thomas

[HappySeagull]

...it sounds hopeless quilting these without reference to wgs84 -which makes perfect sense doesn't it?-so much easier when they are on the same grid. And sailors and airmen really want just one grid anyways... as an example, imagine the mapping before Greenwich and the equator as 0,0 !
Otherwise, to look at national datums is an eclectic pursuit...and for that Quilting is a luxury. It's only near the edge you need really need the "next" chart handy.
...(http://www.kolumbus.fi/eino.uikkanen...oords.htm)...I read your link and my "take-away" is that if the Russians had dared to go to Finland again, they would have been so lost and confused they would never find their way out! Perhaps that was the idea.
National Datums as a statement of sovereignty...just as International ones are a reflection of trade.

[gurmel]

Hello,
Having worked through this thread, I have tried to adapt my OZI-Maps for OpenCPN.
My Ozi Maps, scanned "Mala Karte" from Croatia, Chart Datum "Bessel 1841" work fine with OziExplorer, where they are defined as having Chart Datum "Hermannskogel". Waypoints, GPS-positions, curser fit exactly. AFAIK both nominations refer to the same Chart Datum: Bessel, beeing the man who defined the Ellipsoide, Hermannskogel beeing the point of reference near Vienna. Both nominations can be found on different GPS-Appliances and software.
When using map2kap without entering more then scale, I get the following warning:

"Unexpected combination of latitude/longitude adjustments and chart datum. Assuming WGS 84 chart datum instead of Hermannskogel"

Consequently I get a 0.29 nm E-W deviation between chart and any imput, which is not acceptable.
I have varied the map-header, have used the possibility to give imput in latitude, longitude etc. but could not match Chart-picture, and postion-readings.
Following one of my Ozi-Map Headers:

OziExplorer Map Data File Version 2.2
Mk13-Zadar.jpg
D:\Ozi Daten\Maps\Scan Seekarten\Male Karte2012-50\MK13-Zadar.jpg
1 ,Map Code,
Hermannskogel,LOCAL DATUM, 0.0000, -16.8000,WGS 84
Reserved 1
Reserved 2
Magnetic Variation,,,E
Map Projection,Mercator,PolyCal,No,AutoCalOnly,No,BSBU seWPX,No
Point01,xy, 463, 157,in, deg, 44, 13.4000,N, 14, 50.0000,E, grid, , , ,N
Point02,xy, 3618, 146,in, deg, 44, 13.4000,N, 15, 20.0000,E, grid, , , ,N
Point03,xy, 3623, 2114,in, deg, 44, 0.0000,N, 15, 20.0000,E, grid, , , ,N
Point04,xy, 469, 2124,in, deg, 44, 0.0000,N, 14, 50.0000,E, grid, , , ,N


The -16.8000" corresponds to 0,29 nm E.

Can You please explain, what to do to do to make things fitting.
Thanks!
Gurmel

[HappySeagull]

gurmel, From your post, I am guessing that the kap's "header" names the Datum and includes corrections.

Unexpected ..... latitude/longitude adjustments ....

Can you copy and paste a header from one of your problem "kap"charts to here?

A good text editor can open Kaps as text.

[gurmel]

Thnks for your quick answer.
In my post you can find the requested copy of the map-headers.
Greetings
gurmel

[gurmel]

Originally Posted by HappySeagull

gurmel, From your post, I am guessing that the kap's "header" names the Datum and includes corrections.



Can you copy and paste a header from one of your problem "kap"charts to here?

A good text editor can open Kaps as text.

Correct, the header contains "Hermannskogel" as Chart Datum and the correction to WGS 84 "-16.8" longitude corresponding to 0.29 nm East.
Here comes the copy:

OziExplorer Map Data File Version 2.2
Mk13-Zadar.jpg
D:\Ozi Daten\Maps\Scan Seekarten\Male Karte2012-50\MK13-Zadar.jpg
1 ,Map Code,
Hermannskogel,LOCAL DATUM, 0.0000, -16.8000,WGS 84
Reserved 1
Reserved 2
Magnetic Variation,,,E
Map Projection,Mercator,PolyCal,No,AutoCalOnly,No,BSBU seWPX,No
Point01,xy, 463, 157,in, deg, 44, 13.4000,N, 14, 50.0000,E, grid, , , ,N
Point02,xy, 3618, 146,in, deg, 44, 13.4000,N, 15, 20.0000,E, grid, , , ,N
Point03,xy, 3623, 2114,in, deg, 44, 0.0000,N, 15, 20.0000,E, grid, , , ,N
Point04,xy, 469, 2124,in, deg, 44, 0.0000,N, 14, 50.0000,E, grid, , , ,N

Greetings
gurmel

[HappySeagull]

it's been awhile since I used Map2kap and I haven't ever tried Hyman's version, so I'm making it up until Hyman comes back!
I don't know if there's any ability to change datums in the finished kap. I haven't seen an example of this.

(Nowadays, I just calibrate two diagonal corners of the picture to WGS 84 and run it through imgkap....it saves problems later)

...but just to look at your issue, I'd try different versions of
"Hermannskogel,LOCAL DATUM, 0.0000, -16.8000,WGS 84"
and first, see if the map2kap error goes away and a kap is made.....

first, try
Hermannskogel,LOCAL DATUM, 0.0000, 0.0000,WGS 84

If the error goes away and a kap is made,try to load it in opencpn just to see what happens...

Report back as to how it looks in opencpn.

and, experiment. Here's an example from this post http://www.cruisersforum.com/forums/...ml#post1309063
and this post that is about the earlier map2kap.
http://www.cruisersforum.com/forums/...tml#post636427

compare the ozi map headers to yours
I note that Tecknik did not try to correct the datum.
I note that Open CPN displayed the chart correctly(a recognized datum) but could not quilt it.

Using those examples, I changed yours a little more-try this.

Hermannskogel,, 0.0000, 0.0000,WGS 84

if that makes a kap, Then try

Hermannskogel,, 0.0000, -16.8000,WGS 84

or even this, because the double commas and asivieros post made me wonder

Hermannskogel,WGS84, 0.0000, -16.8000,WGS 84

[hyman]

Hi gurmel,

ther warning message you get is not from the map2kap script I wrote, but from one of the tools the script invokes internally. The script itslef doesn't even look at the chart datu, it just passes that on as-is.

Have you ever tried to use "Bessel 1841" instead of "Hermannskogel"?

[dmurias]

Originally Posted by hyman

Since I am moving to a new Laptop that has Windows 7, I have done the installation on Windows 7 for the first time. Here is how it differs from Windows XP:

• You can safely use Ruby 2.0.0 instead of 1.9.2
• You may want to install Ruby under "Program Files" rather than in the default location the installer offers (the root directory of your system drive)
• Make sure you tick the following options during the Ruby install:
  • Add Ruby executables to your PATH
  • Associate .rb and.rbw files with this Ruby installation
• In the Windows 7 Control Panel, you can edit the PATH under "System" (or easily find the right place by searching for "environment")

Keep converting charts, sailing & cuising ...


Horst

Hi Horst
Please, help!
I have tried to follow your instructions but when I run the command map2kap.. .the system asks me to identify program to run the map2kap.rb
See attached screen.
Thank you

Diego

[hyman]

Hi Diego,

my first guess would be that you might not have the Ruby programming language installed at all. Be sure you download and install version 2.0.0 (either 32bit or 64bit, whichever fits your operating system).

Then during installation be sure to tick the two options:

• Add Ruby executables to your PATH
• Associate .rb and.rbw files with this Ruby installation

If that doesn't help, then I am out of clues...

Regards

Horst