The Photo Keywords program is a small lightweight utility designed for the Mac OS X which will enable you to add keywords directly to a photograph which can be extremely useful if you are scanning film negatives.
More information about the Photo Keywords program can be seen on the Photo Keywords page
The program is driven by the ExifTool command line program which was created by Phil Harvey. The FREE ExifTool program needs to be installed first and is available from https://www.sno.phy.queensu.ca/~phil/exiftool/
ExifTool for Mac OS X can be downloaded here. https://www.sno.phy.queensu.ca/~phil/exiftool/ExifTool-10.51.dmg