[vtkusers] Incompatible libpng version in application and library

[Martin Baumann]

Hi,

I am using VTK-4.2 and QT4.
When I try to create a *.png image file I get the following error:

   libpng warning: Application was compiled with png.h from libpng-1.0.12
   libpng warning: Application  is  running with png.c from libpng-1.2.8
   libpng error: Incompatible libpng version in application and library
   ERROR: In /home/martin/local/src/vtk/vtk-4.2/IO/vtkPNGWriter.cxx, 
line 156
   vtkPNGWriter (0x8295418): Unable to write PNG file!

It seems as if VTK-4.2 comes with libpng-1.0.12 and QT4 comes with 
libpng-1.2.8.
I tried to disable the use of libpng-1.0.12 when I configured VTK. I did 
the following:

cmake
-> toggle to advanced mode
-> VTK_USE_SYSTEM_PNG               ON

(I left the following with its standard values:)
-> PNG_LIBRARY                          /usr/lib/libpng.so
-> PNG_PNG_INCLUDE_DIR       /usr/include


But this didn't help!

How can I find what libpng versions are a certain png.h or png.cpp or 
libpng.so?
I am not sure what I have to set for PNG_LIBRARY and PNG_PNG_INCLUDE_DIR 
because I
don't know where I find the 1.2.8 versions of the files.
I have three or four png.h png.cpp and libpngX.so


Thanks, MB