The primary way to obtain version 7.1.1-15 is through official archive repositories. While the main download page typically features the latest stable release (currently 7.1.2-x), legacy versions are maintained in specific directories.
The checksums for all releases are typically hosted alongside the binaries. imagemagick 7.1.1-15 tar.gz download releases url
If the specific version is archived or moved, it can typically be found in the main releases directory: The primary way to obtain version 7
sudo apt-get update sudo apt-get install build-essential libjpeg-dev libpng-dev libtiff-dev \ libgif-dev libx11-dev libxml2-dev libwebp-dev \ librsvg2-common libopenexr-dev imagemagick 7.1.1-15 tar.gz download releases url