The following command should work to build Multiblend on Linux:

  g++ -msse4.1 -pthread -ffast-math -Ofast -o multiblend multiblend.cpp -lm -lpng -ltiff -ljpeg

Harry van der Wolf suggests the following for Mac:
- for HomeBrew
  [install home brew]
  brew install jpeg-turbo libjpeg libpng libtiff
  gcc -I/usr/local/opt/jpeg-turbo/include -L/usr/local/opt/jpeg-turbo/lib -std=c++14 -msse4.1 -pthread -ffast-math -Ofast -o multiblend multiblend.cpp -lm -lpng -ltiff -ljpeg -lstdc++


- for MacPorts
  [install MacPorts using the pkg for your MacOS version]
  sudo port -v selfupdate
  sudo port install jpeg
  sudo port install libjpeg-turbo
  sudo port install tiff
  sudo port install libpng
  gcc -I/opt/local/include -L/opt/local/lib -std=c++14 -msse4.1 -pthread -ffast-math -Ofast -o multiblend multiblend.cpp -lm -lpng -ltiff -ljpeg -lstdc++