Aerial photos

[Stefanie Weykam]

Nhamoinesu,
this is the 'world file format' (jgw is just the same as tfw):

ESRI World File Format

Used as attribute file associated with corresponding image file.
World files consist of 6 lines, denoting the following:
sampleFile.tfw
5.000000000000	(size of pixel in x direction)
0.000000000000	(rotation term for row)
0.000000000000	(rotation term for column)
-5.000000000000	(size of pixel in y direction)
492169.690845528910	(x coordinate of centre of upper left pixel in map units)
5426523.318065105000	(y coordinate of centre of upper left pixel in map units)

If you open the image in Photoshop, PhotoEditor or similar, you may look up the image size in pixels (width and height) so that you can calculate the extension in UL, LL, LR, UR. Remember, you have the midpoint of the pixel and need to correct the values for half a pixel.
Anyway, I thing that MapServers reads the world file automatically.

As for the second question - simply echo the variable $imgURL
   $img=$map->draw(); 
   $imgURL=$img->saveWebImage();  
   echo $imgURL;

The result looks like this:
/tmp/ms_tmp/11224525985001.PNG

You can do the same with your legends and reference images...

Stefanie
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Date:    Tue, 26 Jul 2005 17:51:18 +0100
From:    Nhamoinesu Mtetwa <nmt at CS.STIR.AC.UK>
Subject: Aerial photos

Hello there,

How do I form a mapfile base layer using Aerial photos? The files are in
pairs with extensions .jpg and .jgw

One of the .jgw has the following numbers:
0.250000
0.000000
0.000000
-0.250000
166000.000000
45000.000000

which I think are the extent values but I am not sure.

The other question is that: is there anyway of getting the name of the
image that CGI program mapserv creates when one is in browse mode?

Cheers,

Nhamo.

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