Imgkap - kap File Converter Tool

[sinbad7]

lone viper..

I am a Win 7 user....

GE2KAP creates .kap maps from a variety of sources including bitmaps and a calibration file.

Tore

[denverd0n]

I created a chart from an .png file using imgkap. The chart loads into opencpn, and looks okay, but it will not scroll out very far. That is to say, I cannot get it to scroll out to where I see more than about 1/8th of this particular chart on the screen at any one time.

I don't know if this is a problem with the kap file, or with some setting in opencpn. Has anyone experienced anything like this?

Thanks.

[HappySeagull]

denverdOn, I'm assuming you mean "zoom out"? as in magnification...?


Try turning quilting Off in the OpenCPN tool box...because when quilting is on, and if you have other smaller scale (ie:small scale=more area) charts of the same area these will "take precedence" and "grab focus", as you zoom out.
Alternatively, try the Chart Group feature in the newer versions of O. With a group, you can limit which charts are available to O while still being able to quickly switch back to the whole collection if need be.

[lone_viper]

Originally Posted by sinbad7

lone viper..

I am a Win 7 user....

GE2KAP creates .kap maps from a variety of sources including bitmaps and a calibration file.

Tore

Thanks.. But how???

I have tried putting in the image file into the program and it just comes back saying that the file needs to be a KAP.... Thats the bit I dont have?

[HappySeagull]

lone_viper,
wrong thread...try HERE:
http://www.cruisersforum.com/forums/...kap-43680.html

[denverd0n]

Originally Posted by HappySeagull

denverdOn, I'm assuming you mean "zoom out"? as in magnification...?

Yes, I meant zoom out. I have quilting off. I will try groups, but since everything I am trying to look at is only on one chart, I'm skeptical that it will help.

Thanks for the ideas.

EDIT: Nope, tried groups, didn't work. Tried setting this one chart as the only chart that the thing knows about. Still won't zoom out to show me more than about 1/8th of the chart.

[cagney]

Originally Posted by denverd0n

Yes, I meant zoom out. I have quilting off. I will try groups, but since everything I am trying to look at is only on one chart, I'm skeptical that it will help.

Thanks for the ideas.

EDIT: Nope, tried groups, didn't work. Tried setting this one chart as the only chart that the thing knows about. Still won't zoom out to show me more than about 1/8th of the chart.

What version of OpenCPN are you using?
Changes in later versions makes a difference in ability to zoom out, specially in single mode. Take 3.1.814 for a spin and report back.
Apart from this I think we have to look at the chart to see if there are other issues.

Thomas

[denverd0n]

Running 3.0.2 of opencpn. The chart was created with imgkap from a png image. It is NOAA chart 25609, which they no longer have in their catalog--the BVI.

[HappySeagull]

denverdOn, is the chart ok otherwise? good detail? what were the pixel dimensions of the image you "kapped"? Have you turned opengl off and on in the toolbox ? just things to try, though you likely have done everything I can think of, by the sounds of it)

It might be worth a try to resize the image and make an "overview kap" from it. This one , (viewed in Xnview image viewer with the bsb plugin) reports as 7360x5699 but smaller might work.

and I can see it all in OpenCPN 2.6.1310 (an old beta that I happen to have handy to run as portable) sorry for extra bracket-details, but I'm always a bit syncopated as to Mainstream versions but this hopefully shows it's not so much a version thing.



It's always been tricky for me too, to get O to view with what she considers an inferior image-size versus scale. ...

as Thomas says, if you could upload the chart somewheres, we could see more quicker!

[HappySeagull]

PS by the way, if I view more than 1\8 of my example chart, it's absolutely useless to use for navigation. I can barely see shore lines. It's just not the right scale cartography to plan routes beyond a certain length.

[denverd0n]

I uploaded the kap file and the png file that I created it from to filedropper.com. You can download the files here:

http://www.filedropper.com/25609 (png file)
http://www.filedropper.com/25609_1 (kap file)

The png file is big. 17,329 x 11,750 pixels. 13Mb in size with excellent detail. The kap file created from it is 21Mb. Wondering if that is too big, somehow.

I did try disabling opengl and it didn't make a difference.

[HappySeagull]

denveredOn,
sorry for my scattergun solutions- they are just things that pop into the head that at least get the possibility of an easy tweak off the list. I'm thinkinking it's something to do with the chart, anyways.

But I haven't downloaded your chart yet as I'm flapping around right now, but that's a big kap as kaps go! and Kaps are generally smaller in mb size than the original image,(at least mine are) so I'm wondering too.Not to say you can't have a 13mb kap but all the ones I have (homemade or not,are averaging 3mb...max about 6....

[HappySeagull]

Ok, got it. Nice Chart! as to zooming out, best I can do on newest Obeta is:


but gee not useful at that zoom anyways.
Still,
Reducing the dimensions is the obvious idea forward.

[cagney]

It has to do with size and resolution. I have another version of the same chart that's only 4.9 Mb an much less resolution. A lot of energy was spent in the NGA project to find the right balance between size and usefulness. Remember that any chart should not really be used with a zoom factor of 2. The smaller size chart is still very good and pixilation doesn't start to be annoying until a zoom of about 3.5 .

Compare the zoom of these 2 pictures. The scale of the large size chart is corrected to 1:80.000.




The conclusion is that these very large size charts just waste a lot of space and computer cycles to load.

A command similar to

gm convert 25609.png -level 5% -resize 50% -depth 8 -colors 16 -type Palette 25609_1.png

will produce a smaller pictures.

Thomas

[denverd0n]

Well, I couldn't even get it to zoom out that much. I could not zoom out enough, for instance, to see Anegada and any other island.

I like the fact that it has a lot of detail, so I kind of hate to lose that. Do you think it would help to break it up into, say, four separate charts? But keep the current level of resolution in each?

By the way, I want to thank you very much for taking the time to work through this with me.