opencvのrubyバインディングが入らない

sudo apt-get install libcv1 libcv-dev
sudo apt-get install opencv-doc

sudo gem install opencv

で、入らない

Building native extensions.  This could take a while...

ERROR:  Error installing opencv:
        ERROR: Failed to build gem native extension.

/usr/bin/ruby1.8 extconf.rb install opencv
>> check require libraries...
checking for main() in -lcxcore... yes
checking for main() in -lcv... yes
checking for main() in -lhighgui... yes
checking for main() in -lstdc++... yes
>> check require headers...
checking for cxcore.h... no
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers.  Check the mkmf.log file for more
details.  You may need configuration options.

Provided configuration options:
        --with-opt-dir
        --without-opt-dir
        --with-opt-include
        --without-opt-include=${opt-dir}/include
        --with-opt-lib
        --without-opt-lib=${opt-dir}/lib
        --with-make-prog
        --without-make-prog
        --srcdir=.
        --curdir
        --ruby=/usr/bin/ruby1.8
        --with-opencv-dir
        --without-opencv-dir
        --with-opencv-include
        --without-opencv-include=${opencv-dir}/include
        --with-opencv-lib
        --without-opencv-lib=${opencv-dir}/lib
        --with-ffcall-dir
        --without-ffcall-dir
        --with-ffcall-include
        --without-ffcall-include=${ffcall-dir}/include
        --with-ffcall-lib
        --without-ffcall-lib=${ffcall-dir}/lib
        --with-cxcorelib
        --without-cxcorelib
        --with-cvlib
        --without-cvlib
        --with-highguilib
        --without-highguilib
        --with-stdc++lib
        --without-stdc++lib
extconf.rb:41: cxcore.h not found. (RuntimeError)
        from extconf.rb:40:in `each'
        from extconf.rb:40


Gem files will remain installed in /usr/lib/ruby/gems/1.8/gems/opencv-0.0.6 for inspection.
Results logged to /usr/lib/ruby/gems/1.8/gems/opencv-0.0.6/ext/gem_make.out