A client who was using TIF files in SharePoint 2016 reported that the search results didn’t link to the file directly, but rather to the List Item Display Form (DispForm.aspx?ID=x) for these files and wanted that changed.
Most info on the web on how to configure for TIF file indexing is rather outdated and incomplete so here’s an update for SharePoint 2016 and 2019.
1. Enable the TIFF iFilter on all servers configured for “Content Processing” in the Search Topology
Install-WindowsFeature -Name "Windows-TIFF-IFilter"
2. [Windows Server 2012 (R2) only] Enable the Windows Search Service Feature on all servers configured for “Content Processing” in the Search Topology
Install-WindowsFeature -Name "Search-Service"
3. Add both tif and tiff to the list of Crawled File Types for the Search Service Application
4. Add both tif and tiff as a file format to the Search Service Application
$ssa = Get-SPEnterpriseSearchServiceApplication
New-SPEnterpriseSearchFileFormat -SearchApplication $ssa tif "TIFF Image File" "image/tiff"
New-SPEnterpriseSearchFileFormat -SearchApplication $ssa tiff "TIFF Image File" "image/tiff"
5. Restart the SharePoint Search Host Controller on all servers configured for “Content Processing” in the Search Topology
Restart-Service SPSearchHostController
6. Run a Full Crawl
You should now have proper indexing of TIF files.

