warning: libpng16.so.16, needed by /usr/local/lib/libopencv_imgcodecs.so, not found

编译显示错误为：

/usr/bin/ld: warning: libpng16.so.16, needed by /usr/local/lib/libopencv_imgcodecs.so, not found

我的解决方法是：

sudo apt-get remove --purge libpng-dev
sudo apt-get install libpng16-dev

然后重新编译。