Imgkap - kap File Converter Tool

[HappySeagull]

Hola!, M'dJ !

[synp]

Originally Posted by MdJ

Hi all, Happy, Tore, ...

If you have any questions or requests to imgkap, please, it is my pleasure to answer.

M'dJ

Hi. A couple of times, I've converted Google maps to .KAP. I wouldn't use that for an ocean, but they're pretty OK for canal boating and for roads.

I create a URL using Google Maps, then use some utility to create a PNG file from it. The URL actually contains the lat and lon of the image file. However, it doesn't give you the lat and lon of the top left corner, but of the middle of the map. It also gives the size of the map (in degrees). Calculating is pretty easy, but I've modified your code to add a "-c" switch. This changes the interpretation of the lat0,lon0,lat1,lon1 to what Google's URLs have.

Would you like to have this code and maybe incorporate it into your codebase?

[MdJ]

Originally Posted by synp

Would you like to have this code and maybe incorporate it into your codebase?

Hello,
Yes, I can add this option, you can mail me your update (private message or mail alain.cousinie@laposte.net).
I return you a new code, or if you prefer an executable for Windows to test.

There was also a problem on date format (us, eu...).But I do not know how to determine the correct format, system date or origin of the map?

M'dJ

[nohal]

MdJ...
From what I can tell from the docs available and what we used in the NGA charts project, the date should be following the ISO 8601 standard:

diff --git a/imgkap.c b/imgkap.c
index 5da93b2..066f847 100644
--- a/imgkap.c
+++ b/imgkap.c
@@ -4,6 +4,7 @@
  *  Thank to freeimage, libsb and opencpn
  *
  *    imgkap.c - Convert kap a file from/to a image file and kml to kap
+ *    modified by nohal 2011-0812 - changed the format of CED/ED to YYYY-MM-DD
  */
 
 #define VERS   "1.11"
@@ -1482,7 +1483,7 @@ int imgheadertokap(int typein,char *filein,int typeheader, int optkap, int color
 
         time(&t) ;
         date = localtime(&t);
-        strftime(datej, sizeof(datej), "%d/%m/%Y",date);
+        strftime(datej, sizeof(datej), "%Y-%m-%d",date);
     }
 
     header = fopen(fileheader, "rb");

Pavel

[HappySeagull]

....meanwhile, there's this link, that Surveyor found...
Exploring Google Maps

which provides corner coordinates on a grabbed image 1600x1200 or a 3200x2400 image... works in firefox for sure...

Might be good for linux users that are a bit put out they can't use GE2kap etc.

added you will also want screengrab plugin for firefox...
http://www.screengrab.org/

check to see if it'll work in your version of firefox

[MdJ]

[QUOTE=nohal;936489]MdJ...
From what I can tell from the docs available and what we used in the NGA charts project, the date should be following the ISO 8601 standard:
[CODE]

Hello nohal,

Can you indicate the sources where specified ISO 8601 with versions of KAP map?

Because on official maps (SHOM) in v1.1, the date format is "%m/%d/%Y".

M'dJ

[nohal]

MdJ...
My newest Argentinian charts use the same:

CED/SE=0,RE=0,ED=05/26/2009
NTM/NE=0,ND=05/26/2009
VER/3.07

So it looks like both your and our format is wrong...

Pavel

[MdJ]

[So it looks like both your and our format is wrong...]

Yes, it seems that the format is "mm/dd/yyyy" (US)

M'dJ

[globalkeith]

Hi All,

So I've written a script which grabs tiles from a well known search engine and stitches them all together and then feeds the result into imgkap.

I seem to get some strange behaviour with the resulting kap file within OpenCPN.

With quilting turned on, the image does not display complete image and is not in correct location. Also another strange thing is clicking repeatedly on the button causes the image to move upwards a few pixels at a time:



With quilting turned off, (without north up) the image "appears" to be correctly positioned, but incorrectly rotated:



And finally with "North up" enabled, this positioning is off again:



Really my question is, is there something wrong with my kap file which causes this behaviour?

I'm using the latest OpenCPN source from github

When I download tiles, they are jpg, and the stitching is done using imagemagick, and then the call to imgkap is this:

imgkap map.jpg 22.355156 114.252319 22.360236 114.263306 map.kap

Here's the image:



And finally here's the kap:

map.kap.doc


Happy to share my code when I get it working, appreciate any help please.

thanks
Keith

[cagney]

globalkeith

I'm sure that your georeferencing is off, a bit. The position of the corners are not quite correct. It seems mostly to be a latitude glitch.

Thomas

[MdJ]

Originally Posted by cagney

globalkeith

I'm sure that your georeferencing is off, a bit. The position of the corners are not quite correct. It seems mostly to be a latitude glitch.

Thomas

Langue source : anglais
That's right.

See imgkap Version 1

WGS84 positioning:
lat0 lon0 is a left, top point (UNLESS the-c option is specified)
lat1 lon1 is a right, bottom point (UNLESS the-c option is specified)
To Be lat beetwen 85 and -85 degree
To Be beetwen lon -180 and 180 degree
Different formats are accepted: -1.22° 10'20 .123N 1-1d22.123

so try
imgkap 22.360236 114.252319 22.355156 114.263306 map.jpg map.kap
and tell us if it's OK

M'dJ

[globalkeith]

Sweet, thanks guys, finally got it to work!!! Only runs on linux as it relies on curl at the moment, but if anyone wants a copy of the code for educational purposes drop me a pm.

[lone_viper]

I keep getting the 'Please install GraphicsMagick' box come up when I start the program and I have installed it....

Anyone got any idea?

It means that I am unable to use the software to create .KAP files which is somewhat annoying ;-)

[sinbad7]

Probably a path problem. IMG2KAP does not find the neccessary program.

Meantime,try GE2KAP,works very well.

Tore

[lone_viper]

Windows person here... ;-)

Doesnt the GE2KAP program convert Google images to KAP?

I am looking at converting a BMP, that has been run through MapCal to get the DIR calibration file out...

For the life of me I cant find anywhere that give the instructions for windows, or uses a piece of windows software.... I think it is all falling down around the formatting of the image files that photoshop is adding..... The reason for using PS is to bring the colour depth right down to take up less space and increase performance. OpenCPN doesnt seem to like very large files.

Thanks in advance