3D Fax was an early Windows program from InfoImaging Technologies. It allowed binary files to be transmitted via fax, by encoding the file into a printed image to be sent to the recipient's fax machine. The recipient would then scan the transmitted image and use 3D Fax to decode it back to its original binary form.
Its functionality was limited. Although being able to send a binary file via fax is a novel idea, it has three main problems:
- The size of the binary file is limited to what is possible to encode on a letter-sized piece of paper, so sending anything over 50 kb would require many sheets of paper to print, fax, and scan.
- The sending party requires an adequate printer and a fax machine or fax-modem, and the receiving party requires a scanner and fax (although a fax-modem on both sides would eliminate the printer and scanner requirements). Both also need access to a phone line, to send their fax.
- It is essential that the recipient can decode the file perfectly. Corruption can occur at five stages of the process if the documented is printed, faxed and scanned: the original printing of the encoded file, the scanning by the sender's fax machine, line noise in the fax transmission, the printing by the recipient's fax machine and the scan into the recipient's computer. Moreover, the final scan will not be perfectly pixel-aligned with the original. To allow for this, considerable redundancy is needed in the encoding format, making the data capacity of each sheet of paper even less than it would be otherwise.
The advent of an almost ubiquitous Internet, along with email, made the limited usefulness of this software obsolete.