[Mapserver-users] Migration from 3.5 to 4.0

[Vinko Vrsalovic]

Hello,

	I found in some old backups a really nice app that was made in
	good old 3.5 times. Back then it worked perfectly. In it i embedded 
	the scalebar in the map, with transparent set to ON, but now (with 4.0) 
	it the bakcground is not rendered transparent, so it's blocking a 
	part of the map. As i'm using 4.0 I tried to define the 
	following outputformat:

  OUTPUTFORMAT
      NAME png
      MIMETYPE image/png
      DRIVER GD/PNG
      EXTENSION png
      IMAGEMODE RGBA
      TRANSPARENT TRUE
  END

	But when using it, i get 

	gd-png:  fatal libpng error: Invalid number of colors in palette
	gd-png error: setjmp returns error condition

	
	I also get the same error when using IMAGEMODE RGB and TRANSPARENT FALSE
so i guess it has to do with the number of bits instead of the
transparent setting. It works if i set IMAGEMODE to PC256.

	I checked the list, and the problem is mentioned, but didn't
get why it might happen.

	So three questions here, what can I be doing for it to fail that way? 
I was using a reference map with a 8bit png image, so I changed it to 24 bits, 
but the problem remains. 

	The second is, if I get the outputformat with RGBA to work,
will the scalebar with transparent set to true work?

	And the third is, is there a way to embed the scalebar with
transparent background with PC256 mode?

Thanks,
-- 
Vinko Vrsalovic <el[|- at -|]vinko.cl>
http://www.cprsig.cl