While exchanging with the package maintainer about a Stretch update, he discussed the tests he performed before upload (reworded):
- Setup a Stretch/amd64 VM
- Installed the updated tiff packages
- Installed a bank of 50k images ranging from 800x600 to 10k resolution (average ~1.5k+ pixels)
- Converted those from tiff to jpg and then vice-versa using CLI
- Checked for any possible warning from the libraries
- Checked a few thousands of those images randomly and manually, starting the viewer from CLI to see any potential warning messages, and visual checking for issues