[Xastir] PNG,GIF,TIFF,or JPEG images as maps

[Lee Bengston]

I remember asking that question  :-)

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From: Lee Bengston <lee.bengston at gmail.com>
Date: Sun, Sep 7, 2008 at 8:28 PM
Subject: geo files for simple maps
To: Xastir - APRS client software discussion <xastir at xastir.org>


Hi All,

Maybe I just got lost in all the details of information in the HowTo:
Maps and the Readme.maps, but I couldn't find the procedure for
creating a geo file for a scanned or screenshot based map, i.e. a
simple JPG, PNG, or GIF.  I have a map of a course for a public
service event that is basically a screen shot of Yahoo Maps saved as a
JPG.  I recall I need the lat/lon of the upper left and lower right
corners of the map for the geo file, but what else, and what does the
geo file format look like for this type of map?

Thanks,

Lee - K5DAT
Murphy, TX

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From: Alex Carver <kf4lvz at yahoo.com>
Date: Mon, Sep 8, 2008 at 2:46 PM
Subject: Re: [Xastir] geo files for simple maps
To: Xastir - APRS client software discussion <xastir at xastir.org>


It's just a simple .geo like the others you've seen.

First line is the keyword FILENAME and then the filename of the image
Next line is keyword TIEPOINT followed by the pixel x, pixel y,
longitude, and latitude of the pixel
Final line is another TIEPOINT for the opposite corner in the same format.


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---------- Forwarded message ----------
From: Curt, WE7U <archer at eskimo.com>
Date: Mon, Sep 8, 2008 at 3:54 PM
Subject: Re: [Xastir] geo files for simple maps
To: Xastir - APRS client software discussion <xastir at xastir.org>


On Mon, 8 Sep 2008, Alex Carver wrote:

> It's just a simple .geo like the others you've seen.
> First line is the keyword FILENAME and then the filename of the image
> Next line is keyword TIEPOINT followed by the pixel x, pixel y, longitude,
> and latitude of the pixel
> Final line is another TIEPOINT for the opposite corner in the same format.

Explained a bit in README.MAPS and a bit more extensively in the
online help in Xastir itself.

Note that the tiepoints do not have to be at the corners, but you
get a bit more accuracy if they're as close as possible.  Pick two
spots on the map that you know the lat/long of, which are separated
both vertically and horizontally at much as possible.

--
Curt, WE7U.                             archer at eskimo dot com
http://www.eskimo.com/~archer
 Lotto:  A tax on people who are bad at math. - unknown
Windows:  Microsoft's tax on computer illiterates. - WE7U.
The world DOES revolve around me:  I picked the coordinate system!"