image not found

[15737939656]

installed of PyBM3D but still this problem
ImportError: dlopen(/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/pybm3d/bm3d.cpython-36m-darwin.so, 2): Library not loaded: /usr/local/opt/libpng/lib/libpng16.16.dylib
Referenced from: /Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/pybm3d/bm3d.cpython-36m-darwin.so
Reason: image not found