What is the library to be installed for `jasper.h` header file?
jasper.h is part of the libjasper-dev package. This package is not available in Ubuntu 18.04. So try downloading it and install using
cd ~/Downloads
wget http://archive.ubuntu.com/ubuntu/pool/main/j/jasper/libjasper-dev_1.900.1-debian1-2.4ubuntu1.3_amd64.deb
wget http://archive.ubuntu.com/ubuntu/pool/main/j/jasper/libjasper1_1.900.1-debian1-2.4ubuntu1.3_amd64.deb
sudo apt-get install ./libjasper-dev_1.900.1-debian1-2.4ubuntu1.3_amd64.deb ./libjasper1_1.900.1-debian1-2.4ubuntu1.3_amd64.deb