I experienced similar problem while using OpenCV in MacOS El Capitan. Solved the problem using the solution in the link
Solution is to delete some dlylibs in the /usr/local/lib directory and create symbolic links to related files /System/Library/Frameworks/ImageIO.framework/Resources/
cd /usr/local/lib
rm libgif.dylib
ln -s /System/Library/Frameworks/ImageIO.framework/Resources/libGIF.dylib libGIF.dylib
rm libjpeg.dylib
ln -s /System/Library/Frameworks/ImageIO.framework/Resources/libJPEG.dylib libJPEG.dylib
rm libtiff.dylib
ln -s /System/Library/Frameworks/ImageIO.framework/Resources/libTIFF.dylib libTIFF.dylib
rm libpng.dylib
ln -s /System/Library/Frameworks/ImageIO.framework/Resources/libPng.dylib libPng.dylib