E-mail messages contain editable text, whereas a fax document is a single picture image no matter what it contains. Both methods suffice for sending messages that are only to be read by the recipient, and faxes are often accepted for legal documents that require signatures. However, if signatures are not required and the text must be edited, e-mail is the obvious choice because e-mail text is already computer text (ASCII text) and can be immediately copied to and edited by any mail, text editor or word processing program. Making a Fax Editable In order to edit text in a fax, the text must be extracted from the printed page. The document must be scanned, and the shapes of the letters must be analyzed and converted to ASCII text by an optical character recognition program (see OCR). This operation can also be error prone if the paper is smudged or creased. Fax to E-Mail Still Remain Images Faxes turned into e-mail messages and sent to a recipient's e-mail inbox by Internet fax services are still images and no more editable than if they were printed on paper (see Internet faxing). See e-mail and fax.