<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META content="text/html; charset=us-ascii" http-equiv=Content-Type>
<META name=GENERATOR content="MSHTML 8.00.6001.19019"></HEAD>
<BODY>
<DIV><FONT size=2 face=Arial><SPAN
class=679384607-18042011>Hi,</SPAN></FONT></DIV>
<DIV><FONT size=2 face=Arial><SPAN
class=679384607-18042011></SPAN></FONT> </DIV>
<DIV><FONT size=2 face=Arial><SPAN class=679384607-18042011>I am sometimes
getting images with totally odd colours with MS 6.0 beta 6 (and the previous
beta versions) with format image/png; mode=8bit. I have been doing some
testing and I believe I can now reproduce the error.</SPAN></FONT></DIV>
<DIV><FONT size=2 face=Arial><SPAN
class=679384607-18042011></SPAN></FONT> </DIV>
<DIV><FONT size=2 face=Arial><SPAN class=679384607-18042011>The error happens
only if the raster image has overviews. If I delete or rename the external
.ovr file the 8bit png output is correct at any scales. To be sure that there is
nothing odd with the overview file I recreated it with FWTools v. 2.4.2 by using
a basic command</SPAN></FONT></DIV>
<DIV><FONT size=2 face=Arial><SPAN class=679384607-18042011>gdaladdo -r average
-ro suomi1m.tif 2 4 8</SPAN></FONT></DIV>
<DIV><FONT size=2 face=Arial><SPAN
class=679384607-18042011></SPAN></FONT> </DIV>
<DIV><FONT size=2 face=Arial><SPAN class=679384607-18042011>I prepared also my
own outputformat so I could compare the outputs from MS 6.0 and older MS
5.6.5 version. This is my outputformat which I have understood to mean
just the same as the inbuild MS 6.0 outputformat "image/png;
mode=8bit".</SPAN></FONT></DIV>
<DIV><FONT size=2 face=Arial><SPAN
class=679384607-18042011>OUTPUTFORMAT<BR> NAME
'AGG_Q'<BR> MIMETYPE
"image/png"<BR> DRIVER
"AGG/PNG"<BR> EXTENSION
"png"<BR> IMAGEMODE
RGB<BR> FORMATOPTION
"QUANTIZE_FORCE=ON"<BR> FORMATOPTION
"QUANTIZE_DITHER=OFF"<BR> FORMATOPTION
"QUANTIZE_COLORS=256"<BR> END</DIV></SPAN></FONT>
<DIV><FONT size=2 face=Arial><SPAN
class=679384607-18042011></SPAN></FONT> </DIV>
<DIV><FONT size=2 face=Arial><SPAN class=679384607-18042011>With this
outputformat the resulting map is correct with MS 5.6.5 at any scales even if
the .ovr file is in use.</SPAN></FONT></DIV>
<DIV><FONT size=2 face=Arial><SPAN
class=679384607-18042011></SPAN></FONT> </DIV>
<DIV><FONT size=2 face=Arial><SPAN class=679384607-18042011>My conclusion is
that exectly MS 6.0 version is creating at some scales through ADD driver an 8
bit png output with messed up colours, but it happens only if the source
image has overviews.</SPAN></FONT></DIV>
<DIV><FONT size=2 face=Arial><SPAN
class=679384607-18042011></SPAN></FONT> </DIV>
<DIV><FONT size=2 face=Arial><SPAN class=679384607-18042011>If someone is
interested in having a look at this I can prepare and send my mapfile and some
imagery to play with.</SPAN></FONT></DIV>
<DIV><FONT size=2 face=Arial><SPAN
class=679384607-18042011></SPAN></FONT> </DIV>
<DIV><FONT size=2 face=Arial><SPAN class=679384607-18042011>-Jukka
Rahkonen-</SPAN></FONT></DIV></BODY></HTML>