A fax viewer is a computer program made for viewing electronic fax images. Unless a fax machine is connected to the computer or wirelessly connected to the Internet, it may be difficult or impossible for the fax viewer to obtain a fax image. One common function of this viewer is to allow users to add notes to an electronic fax file. This program typically will have some basic image processing functions, such as rotating the image or changing colors. While not true with every viewer, most will encode fax images into tagged image file format (TIFF), because these images are easily faxed.
Many fax machines are just connected to a phone line, which allows them to send faxes to other fax machines. While this is enough for basic fax functioning, a fax viewer will usually be unable to obtain the file being faxed, because these machines have no connection to the computer. For the viewer to get the image, it must be sent from a fax machine that is connected to a computer or from a fax machine that sends out a wireless signal that can be picked up by the computer.
Annotations on a fax document are commonly used to clarify ideas or to fix minor spelling mistakes, but handmade annotations may look sloppy and illegible. Fax viewer programs often have an annotation feature that can add these notes electronically. This commonly makes the notes easier to read, because they are written in a clear computer font, and it may be easier to organize the annotations.
Most fax viewer programs also will come with basic image processing tools so the user can make some changes to the file. For example, these programs may have rotating functions, they may be able to change how wide the text is, and they typically can add colors. Colors may not appear if this file is sent to a black and white fax machine but, if a word or segment is highlighted, this will typically show up as a dull gray that helps emphasize a section.
The majority of fax viewer programs are made to encode images into TIFF files, or to understand only TIFF images. This is because TIFF is the most commonly used image format for faxing, because the characters can be easily recognized, this image format normally has good quality, and the memory compression makes the files lightweight. At the same time, some fax viewers may be able to view images in other formats.