Apple is working on ways to easily capture digital signatures, per a patent (number 20120093409) at the U.S. Patent & Trademark Office.

Systems, methods, and computer-readable media are provided for capturing a signature, and placing a representation of the captured signature in an appropriate field of a document. A camera or other appropriate sensor can capture an image of a signature provided by a user on a piece of paper. The signature can be digitized to create a representation that a device may use in a displayed document.

To determine where to place the representation, a horizontal line of a document can be identified by selectively rendering portions of the document adjacent to an input position, and identifying one or more boundaries for a detected horizontal line. The representation can be scaled to fit in a detected field of the document.

Here's Apple's background on the invention: "Some electronic devices can be used to enter data in documents displayed by the device. For example, a device can display a document provided by an electronic document file, such as a portable document format ('PDF') file document or a word processing file document, that may include one or more text fields in which text can be entered. In particular, a user can select a particular field, and a provide text input information using an input interface of the device.

"Text corresponding to the text input information can be displayed in a text field of the document, and saved or printed as part of the document file. Some documents, however, must be signed by a user. For example, government-issued or legal documents can require a signature before being filed. When such documents are created or filled-in on an electronic device, a user may not have a simple mechanism for including a signature in the document.

"Instead, a user may be forced to print a physical hardcopy of the document, sign the printed document, and transmit the signed physical document to a receiving party (e.g., by mail, facsimile, or by scanning the signed physical document and e-mailing the scanned document). This approach can be time consuming and burdensome for a user."

Matthew Sarnoff is the inventor.