I can confirm that this annoying warning message also occurs with the 
OpenSuse Factory distro. I first noticed that this was occuring with 
PlayOnLinux 4.2.1-1.1 after updating my packages from OpenSuse 12.3 to 
OpenSuse Factory (latest packages). I believe that the warning started 
occuring with my update to Libpng16-16 (v 
1.6.2-2.2). 
Research into Libpng's documented changes led me to : 
http://www.libpng.org/pub/png/libpng-manual.txt
Changes
 to Libpng from version 1.5.x to 1.6.x can be found in section XII. 
However, I will post the portion that I believe is relevant below for 
convenience.
Error detection in some chunks has improved; in particular the iCCP chunk
reader now does pretty complete validation of the basic format. Some bad 
profiles that were previously accepted are now rejected, in particular the 
very old broken Microsoft/HP sRGB profile.The PNG spec requirement that 
only grayscale profiles may appear in images with color type 0 or 4 and 
that even if the image only contains gray pixels, only RGB profiles may 
appear in images with color type 2, 3, or 6, is now enforced. The sRGB 
chunk is allowed to appear in images with any color type.
As you can see above, some of the bad profiles that were previously accepted are now being rejected. 
From
 there, I decided to gather information from one of the PNG images that 
came with POL (as discussed earlier in this topic) that is causing the 
warning. I started with the cmd.png image and looked into more 
information about it by sending the commands below.
identify -verbose cmd.png
A
 lot of information was displayed about the PNG file as expected, but at
 the end of the ouput, the information that appeared relevant for 
researching this problem has been shown below.
Version: ImageMagick 6.8.5-7 2013-06-17 Q8 http://www.imagemagick.org
identify: iCCP: known incorrect sRGB profile `cmd.png' @ warning/png.c/MagickPNGWarningHandler/1830.
From here, I decided to research the png.c file to gather more information which led me into too much code to look at. 
Afterwards,
 I decided to look for newer changes that have been made since 
ImageMagick 6.8.5-7 which was the version used for the PNG file (as 
shown above).
I came across discussions of corrupted color profiles regarding the JPEG format. 
Also,
 if an image went from JPEG to PNG, it could cause the color profile to 
be corrupted. I'm assuming that this may be what has happened by 
creation of the images for POL. I'm not sure if this could be the only 
way that it could happen, but I believe that they have a fix for this 
with newer versions of ImageMagick.
The change log discussing this issue can be found below.
http://www.imagemagick.org/script/changelog.php
The changes that I believe are relevant has been shown below for convenience.
- 2013-06-26  6.8.6-3 
 
 
-  Improve HCL to RGB roundtrip 
 
- (reference    http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=22384).
 
-  Prefer external log configuration file to built-in (reference    
http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=23640).
 
-  Do not log in the IsLinkedListEmpty() method to prevent overflow 
(reference    
http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=23640).
 
-  Fix bug loading TGA image with 32-bit palette (reference    
http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=17889).
 
-  Color profiles are no longer corrupted for the JPEG format 
(reference    
http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=23651).
 
-  Repair problem with -emboss / -equalize problem (reference    
http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=23643).
And
 on another version they have also made changes to keep from writing 
jpeg properties into a PNG output. The HCLpColorspace change also may be
 relevant.
- 2013-07-21  6.8.6.7 
-  Do not write "jpeg:" properties in a PNG output file (reference  
  
http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=23794).
- 2013-07-24  6.8.6-7 
 
-  Missing case for HCLpColorspace (reference    http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=23811).
My conclusion :
For
 users using POL that have the warning message discussed, I recommend to
 follow the instructions discussed earlier in this topic to correct the 
images. However, there are also alternative ways to recreate the color 
profile if you wish to research into those ways.
For myself, I corrected this issue by manually changing each image by using the command below.
convert filename.png -strip filename.png
For
 the POL development team, please include images in the next version 
that do not have this issue. Consider trying the latest ImageMagick 
version for saving PNG files. I believe that the 
bug is originating from ImageMagick and not POL.However,
 it is directly affecting POL users. I believe that it would be a 
disadvantage for users to consider downgrading their version of Ligpng 
to not see the warning. Reason being, the issues will still remain 
within the PNG files, but will just be suppressed. Also, I believe that 
users that have manually corrected the images for this warning 
themselves will appreciate not having to correct them again with any 
newer versions of POL.
Hope this helps.
Jayzon                            
Edytowane przez Jayzon