Creating KAPs is easy they said....

[Daddy's Dream]

I went the ge2kap route. It works awesome as lone as i dont exit the program and reopen it. It gives me an error when i do that. Uninstalling and reinstalling fixes it until i exit it again.

I wont be home until after midnight today. I'll post the error message when i get home.

Sent from my SM-G920P using Cruisers Sailing Forum mobile app

[jamhass]

Originally Posted by Daddy's Dream

Will it accept jpegs.
I'll take a look at it.

No, only from several online sources, Google earth, maps, etc. All described on the website. Just google chartaid, all one word.

[Daddy's Dream]

After restarting my computer I'm happy to report that ge2kap is working perfectly.

[conachair]

Originally Posted by Daddy's Dream

After restarting my computer I'm happy to report that ge2kap is working perfectly.

One more thing, google earth images can be really useful for anchorages etc as an addition to proper charts, ge2kap makes it easy to create kap charts from google earth.

[Daddy's Dream]

Originally Posted by conachair

+1

I just checked it works..
Don't think I can upload the file here though..

One vital step that's easy to miss, you need to set the number of colours to 64, I used a prog called xnview - XnView Software · Software for reading, organizing and processing images , then used tools|batch convert..

I follow this method to the letter and got pink charts just like you did. Is there any way to convert these without ending up with pink charts?

[phiggins]

Can email me the .jpg and the CHARTCAL.DIR so I ca see why you are getting pink. My email is in Help (F1).

[conachair]

Originally Posted by phiggins

Can email me the .jpg and the CHARTCAL.DIR so I ca see why you are getting pink. My email is in Help (F1).

Send, thanks

[phiggins]

Daddy's Dream,

OK first let me explain about images and charts. The original image can have up to 16 million colors and is known as an RGB image sometimes referred to as a photometric image. Each pixel contains the color information in three bytes: Red Green and Blue and a byte for the alpha layer specifying its transparency.

Charts (.Kaps) are a much simpler image file that contain a maximum of 127 colors because they normally only need a few colors for the land, some for the different water depths and colors for the navigation objects like buoys. Also, these images are not RGB images they are what is called an indexed image. In an index image each pixel does not have the color information, instead they contain a pointer that is an index into a list that has the color information. This list is called a palette and the maximum size is 127 entries. Each entry has the RGB information. Thereis no alpha byte.

So to create a chart from the original RGB image it must be converted into an indexed image with a maximum of 127 colors. The process of reducing the colors is called dithering. There are various algorithms for dithering. In the process of reducing colors from a possible 16 million to 127 some colors may be lost and replaced by others thus the pink.color for the water. Sometimes rather than letting GE2KAP do the dithering its better to first reduce the colors using an image processing program. I recommend using a program called GIMP which is a free image processing program. I have not tried Xnviewmp. But the process is probably the same: Load the Image, Convert it to an indexed image, then dither the colors down to 127 or less. You can download GIMP here:

GIMP - Downloads


I will answer your other issues in emails.

Paul

[phiggins]

conachair,

I converted the JPG you sent to a PNG using GIMP and then produced a chart with GE2KAP ad here is the result...No pink.

[conachair]

Originally Posted by phiggins

conachair,

I converted the JPG you sent to a PNG using GIMP and then produced a chart with GE2KAP ad here is the result...No pink.

Thanks. I was just about to do the same
I've just downloaded gimp, ta V much for the link, I thought gimp was linux only.

[phiggins]

Conachair,

To be more specific about how to use GIMP.

1. Open the .JPG file
2. On the Image tab select Mode, Indexed
3. Enter 127 in Maximum Number of Colors
4. Press Convert
5. On the Files TAB select Export As...
6. On the Export as select the type as .png and set the file name as .png
7. Press Export
8. on Export image as PNG press Export.

[StuM]

Another easy to use tool to adjust images is Irfanview. I highly recommend it.

IrfanView - Official Homepage - one of the most popular viewers worldwide

[conachair]

Originally Posted by phiggins

Conachair,

To be more specific about how to use GIMP.

1. Open the .JPG file
2. On the Image tab select Mode, Indexed
3. Enter 127 in Maximum Number of Colors
4. Press Convert
5. On the Files TAB select Export As...
6. On the Export as select the type as .png and set the file name as .png
7. Press Export
8. on Export image as PNG press Export.

Yep, that works. GE2Kap seemed to create the kap file lots faster with the png created from gimp compared to xnview.

[phiggins]

Good. You could also use the Irfanview as StuM suggests. In some ways its simpler than GIMP. Just click Image "Decrease The Color Depth" and select Custom 127. Then save it as a PNG, no need to to Export which is something GIMP introduced in V2.8. which I don't like.

[Daddy's Dream]

You guys are awesome. I'll try Gimp when I get home this evening. Thank you.