title: Package gtk-engines-2 was not found in the pkg-config search path
body: <p>I am trying to compile Rob Hess's C implementation of SIFT algorithm.
  I installed OpenCV 2.1 successfully and tested the installation with sample C programs provided. There was no error.</p>
  
  <p>This code I am trying to compile was written using OpenCV 2.0. I successfully compiled and ran the exact code sometime back with OCV2.0 . But now compilation fails and prints this. I am using the make file provided with the code.</p>
  
  <pre><code>make -C ./src siftfeat
  make[1]: Entering directory `/home/niroshan/sift/src'
  ar rc ../lib/libfeat.a imgfeatures.o utils.o sift.o kdtree.o minpq.o xform.o refine.o
  ranlib  ../lib/libfeat.a
  gcc  -I../include `pkg-config --cflags opencv gtk-engines-2` siftfeat.c -o ../bin/siftfeat -L../lib -lfeat `pkg-config --libs opencv gtk-engines-2`
  Package gtk-engines-2 was not found in the pkg-config search path.
  Perhaps you should add the directory containing `gtk-engines-2.pc'
  to the PKG_CONFIG_PATH environment variable
  No package 'gtk-engines-2' found
  Package gtk-engines-2 was not found in the pkg-config search path.
  Perhaps you should add the directory containing `gtk-engines-2.pc'
  to the PKG_CONFIG_PATH environment variable
  No package 'gtk-engines-2' found
  In file included from siftfeat.c:18:
  sift.h:23: fatal error: cxcore.h: No such file or directory
  compilation terminated.
  make[1]: *** [siftfeat] Error 1
  make[1]: Leaving directory `/home/niroshan/sift/src'
  make: *** [siftfeat] Error 2
  </code></pre>
  
  <p>Probably there is another problem with including cxcore.h
  Could someone explain me whats wrong here?
  Thank you in advance</p>