Determining the image compression algorithm used on TIFF images

Use W_Whalley's identify -verbose suggestion instead. If you're in a linux/cygwin environment, pipe it to grep -i compression and you'll have your one-line answer. I.e.

identify -verbose /path/to/your/file.tiff | grep -i compression

If you have imagemagick installed, use the display tool to show the image. Right-click on the image and choose Image Info, then look for the Compression: setting (it's near the bottom of the list). Or if you want the minimum information use the identify tool with the -verbose switch, then filter the result to look for the Compression line.

What about the file command? Example:

$ file /usr/share/apache2/icons/a.png
/usr/share/apache2/icons/a.png: PNG image, 20 x 22, 4-bit colormap, non-interlaced