[MS4W-Users] IMPORTANT: JPEG Output broken in MS4W 6.0 betas (patch ready)

Jeff McKenna jmckenna at gatewaygeomatics.com
Fri Apr 15 13:45:29 EST 2011

Jukka on the MapServer-users mailing list point out recently 
that any 6.0 mapfile that tries to output a jpeg image ('image/jpeg') 
creates an invalid empty image with MS4W.

Short version:
Please everyone test this patch for jpeg and your preferred output 
formats and provide feedback 

Long version:
Through the ticket (http://bugzilla.maptools.org/show_bug.cgi?id=2313) 
and on IRC chat we narrowed it down to the GD library: in fact GD was 
pointing to a non-existent JPEG version, 6b, but MapServer was built 
against a newer JPEG version, 8b, and JPEG wasn't happy about this.  So 
a patch is now available that upgrades your JPEG library to 8c and 
contains a rebuilt GD version, pointing to that new JPEG version. 
Please test it with jpeg output (in any mapfile, specify 'IMAGETYPE 
image/jpeg' and then test with 'shp2img -o test.jpg').  While you're at 
it, give it a test in your other favourite output formats as well.

I apologize for any inconvenience.  I guess it is a good thing this was 
discovered in the 6.0 beta phase, before a full MS4W version was released.

Again thanks to Jukka for reporting this!


Jeff McKenna
MapServer Consulting and Training Services

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