Compare with the official hash. For 7.1.1-15, the correct SHA256 is (example – verify independently):
Support for an arbitrary number of pixel channels and floating-point storage reduces rounding errors.
Download the checksums file (if available for your version) from https://imagemagick.org/archive/digest.rdf or the GitHub release page.
Historical releases can often be found at ImageMagick Archive Releases.
curl -L https://github.com/ImageMagick/ImageMagick/archive/refs/tags/7.1.1-15.tar.gz -o ImageMagick-7.1.1-15.tar.gz