Ubuntu over 14 will no longer support libpng12, however, some software are also dependent on libpng12 (as I want to use the Cisco Packet Tracer). libpng-specific version of the method of installing low we can use.
sudo vim /etc/apt/sources.listFollow the prompts to Ubuntu official website, in which we adddeb http://cz.archive.ubuntu.com/ubuntu xenial main
After installation you can then save, and update the package list
sudo apt-get update
sudo apt-get install libpng12-0
或者 下载 libpng12
sudo mv libpng12.so.0 /usr/lib/x86_64-linux-gnu/