Problem displaying some NOAA BSB nautical charts
dcoggin
Global Mapper UserTrusted User
Hello Mike,
I'm having a problem with GM 15.1 (b013014 64-bit) displaying certain BSB charts correctly. I have checked these charts in another viewer and they display correctly. GM displays almost all charts correctly; I'm just having a problem with a couple. I'll attach a chart I'm having trouble with and a picture of what I'm seeing when loading a panel from the chart (NOAA chart 11472 - 11472_8.KAP). Other panels from that same chart load fine.
Thanks for taking a look at it.
David
I'm having a problem with GM 15.1 (b013014 64-bit) displaying certain BSB charts correctly. I have checked these charts in another viewer and they display correctly. GM displays almost all charts correctly; I'm just having a problem with a couple. I'll attach a chart I'm having trouble with and a picture of what I'm seeing when loading a panel from the chart (NOAA chart 11472 - 11472_8.KAP). Other panels from that same chart load fine.
Thanks for taking a look at it.
David
Comments
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David,
It is odd, it seems that the control points provided for that small inset chart are causing some massive distortion with the default image rectification method (piecewise affine). If you right-click on the layer after loading and specify to Reposition (Rectify) then under the Options menu change the Rectification method to Affine the result it a much nicer picture. I haven't yet identified which control point(s) are causing the problem, but that does fix it.
Thanks,
Mike
Global Mapper Guru
geohelp@bluemarblegeo.com
Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation -
Mike,
Maybe it helps to have another problem child -- panel 11472_7 from that chart is also distorted. The other eight panels from that same chart are fine. Good luck!
David -
David,
I've updated the import to automatically use the Affine rectification for small BSB charts where no large errors at the control points are introduced by using the Affine method. This fixes the problem charts. I have placed a new build at http://www.bluemarblegeo.com/downloads/global-mapper/global_mapper15.zip with the latest changes for you to try. Simply download that file and extract the contents into your existing v15.xx installation folder to give it a try. If you are using the 64-bit v15 version there is a new build at http://www.bluemarblegeo.com/downloads/global-mapper/global_mapper15_64bit.zip .
Thanks,
Mike
Global Mapper Guru
geohelp@bluemarblegeo.com
Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation -
Thanks, Mike. Works great!
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