Change RESOLUTION

[Ed McNierney]

Sture -

Remember that pixels are just pixels.  The output resolution depends on
YOU - how many pixels do you want?

The MapServer RESOLUTION setting is used for scale calculations, and is
unnecessary for what you want to do.  Suppose you have an image of a
certain geographic extent on the screen - say it's 100 kilometers by 100
kilometers.  And that image is 400 x 400 pixels on the screen, and
that's about 10 cm by 10 cm on the screen, or a resolution of about 40
pixels / cm.

Now you'd like a print version of that image.  You'd like the printed
version to also be 10 cm by 10 cm, but you'd like to print it at a
resolution of 120 pixels / cm.  So you just need to ask for 3 times as
many pixels.  Change the image request to be 1,200 x 1,200 pixels while
keeping the geographic extents the same (100 km by 100 km).  There's
your high-resolution print image.

Just remember that you can't do that in your Web browser, because your
browser will get in the way and "help" with the printing.  But you can
download that image and use another application to print it.

     - Ed

Ed McNierney
President and Chief Mapmaker
TopoZone.com / Maps a la carte, Inc.
73 Princeton Street, Suite 305
North Chelmsford, MA  01863
ed at topozone.com
(978) 251-4242  

-----Original Message-----
From: UMN MapServer Users List [mailto:MAPSERVER-USERS at LISTS.UMN.EDU] On
Behalf Of Sture Dingsoyr
Sent: Thursday, November 17, 2005 1:05 PM
To: MAPSERVER-USERS at LISTS.UMN.EDU
Subject: [UMN_MAPSERVER-USERS] Change RESOLUTION

Hi

Is it possible to change the RESOLUTION of a produced image (e.g a
TIF/JPEG)?

The reason i want to do this is to be able to use the image for printing
prurposes...obviously a resolution of 72 is ok for use on the web
(screen). But if one wants to print the produced image on paper a higher
resolution wouldt have been great...

I try to set the RESOLUTION option in the MAP file...but nothing
happens...is the RESOLUTION option a constant set to 72?