Re #3.
Looks like you have the zlib headers.
Suggest : Copy { zlib.h, zconf.h } to opencv-2.4.11/<??>
.. or to a "/home/<name>"/include/ folder, and add the new "include" to the cmake command,
like $ cmake -DCMAKE_CXX_FLAGS="-I /path/to/dir" ../
http://stackoverflow.com/questions/1...ional-includes
Tracing all the zlib headers : $ dpkg -L zlib1g-dev
/usr/include/x86_64-linux-gnu/zconf.h
/usr/include/zlib.h
Important : You
can confuse 'cmake' if you are compiling in opencv-2.4.11/.
The common way is to use a build folder : opencv-2.4.11/build/, and :
$ cd build/
$ cmake ../
( You may have to start from scratch, with a new unpacked opencv-2.4.11.tar.gz ).
... Also be aware that the current stable version is opencv-2.4.9 ( or 2.4.8 ) :
2.4.9 : See Debian Sid / Ubuntu Vivid / Fedora 23.
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