title: fatal error: png.h: No such file or directory(MiddleBury Evaluation)
body: <p>I am testing stereo algorithm in MiddleBury Stereo Evaluation</p>
  
  <p>One of step was to compile the tools in code/as follows.</p>
  
  <pre><code>cd code/imageLib
  make
  cd ..
  make
  cd ..
  </code></pre>
  
  <p>In this case, there is error in first <code>make</code> as follows,</p>
  
  <pre><code>$ make
  g++  -O3 -W -Wall -g  -c -o ImageIOpng.o ImageIOpng.cpp
  ImageIOpng.cpp:19:17: fatal error: png.h: No such file or directory
  compilation terminated.
  make: *** [&lt;builtin&gt;: ImageIOpng.o] Error 1
  </code></pre>
  
  <p>and, regarding second <code>make</code>,</p>
  
  <pre><code>$ make
  g++  -g -O3 -W -Wall -IimageLib   ii.cpp  -LimageLib -lImg.i686-g -lpng -lz -o ii
  /usr/lib/gcc/i686-pc-cygwin/5.4.0/../../../../i686-pc-cygwin/bin/ld: cannot find -lImg.i686-g
  /usr/lib/gcc/i686-pc-cygwin/5.4.0/../../../../i686-pc-cygwin/bin/ld: cannot find -lpng
  collect2: error: ld returned 1 exit status
  make: *** [&lt;builtin&gt;: ii] Error 1
  </code></pre>
  
  <p>In previous step, <code>make</code> worked fine. 
  So, what was the problem? I downloaded sample algorithm and did not edit/change contents in any file.</p>