(There's no video for XFacer yet. Please contribute to MR and add a video now!)
XFacer is a simple application for cropping pictures and reducing them to 48-by-48-pixel black-and-white icons.
James Ashton explains it best on his web site: (https://web.archive.org/web/20110706113756/http://users.cecs.anu.edu.au/~jaa/)
X-Face is a file format used to allow a small image to be included with mail items. Typically the image shows the sender's face and is included in the mail headers labelled X-Face: . ... I devised the format to contain 48x48x1 (i.e. black and white) images in the minimum possible space. With care in production, dithered images of faces are surprisingly recognisable given their small size...
How to do it:
XFacer.dmg (245.86 KiB / 251.76 KB)
/ DMG image
Emulating this? It should run fine under: SheepShaver