Biomedical subjects

Paul Blenkhorn

Publications and source records attributed to Paul Blenkhorn.

6 recordsLinked to original sources

PubMed2006

Clearspeech: a display reader for the visually handicapped.

Many domestic appliances and much office equipment is controlled using a keypad and a small digital display. Programming such devices is problematical for the blind and visually handicapped. In this paper, we describe a device that may be used to read the displays on these devices. The device is designed to accept a description of the display being read, which specifies the types and locations of elements of the display. Images are captured using a handheld webcam. Images are processed to remove the distortions due to the camera orientation. The elements of the screen are interpreted and a suitable audio output is generated. In suitably illuminated scenes, the display data is interpreted correctly in approximately 90% of the cases investigated.

Communication Devices for People with Disabilities↗

PubMed2006

A screen magnifier using "high level" implementation techniques.

This paper presents the architecture of, and the techniques used to build, a screen magnifier for visually impaired people that uses the "high-level" features of the Microsoft Windows operating system. The magnifier uses information from the Desktop Window as its source and overlays this with a topmost, transparent, layered window that contains the magnified image. Issues concerning cursor enlargement, tooltip suppression, and focus tracking are discussed. A stable magnifier results that does not need to use the "dirty" low-level techniques that are typically used to build screen magnifiers. The only known problem of the magnifier is that it fails to suppress the original, unmagnified cursor of the few applications that use custom cursors.

Communication Devices for People with Disabilities↗

PubMed2004

Producing preferred format material from Microsoft Word.

This paper presents a set of tools that are integrated with a word processor to produce documents in a visually impaired person's "preferred format." The paper considers the motivation for producing such tools and describes tools to perform spoken transcription (to cassette tape) and intelligent large print production.

Communication Devices for People with Disabilities↗

PubMed2003

An investigation into formatting and layout errors produced by blind word-processor users and an evaluation of prototype error prevention and correction techniques.

This paper presents the results of an investigation into tools to support blind authors in the creation and checking of word processed documents. Eighty-nine documents produced by 14 blind authors are analyzed to determine and classify common types of layout and formatting errors. Based on the survey result, two prototype tools were developed to assist blind authors in the creation of documents: a letter creation wizard, which is used before the document is produced; and a format/layout checker that detects errors and presents them to the author after the document has been created. The results of a limited evaluation of the tools by 11 blind computer users are presented. A survey of word processor usage by these users is also presented and indicates that: authors have concerns about the appearance of the documents that they produce; many blind authors fail to use word processor tools such as spell checkers, grammar checkers and templates; and a significant number of blind people rely on sighted help for document creation or checking. The paper concludes that document formatting and layout is a problem for blind authors and that tools should be able to assist.

Adult↗

PubMed2002

A modified Perkins Brailler for text entry into windows applications.

In this paper, we describe how a Perkins Brailler can be adapted so that it can function as a keyboard to a personal computer. The paper describes the earlier work of others and the hardware and software of our system and concludes with indications of how the system may be improved.

Blindness↗

PubMed2002

Full-screen magnification for windows using DirectX Overlays.

This paper presents the basic features of software-based magnifiers used by some visually impaired people to read information from a computer screen. The paper briefly presents two major approaches to full-screen magnification for modern multiple window systems (the paper focuses on Microsoft Windows). This paper describes in detail the architecture and operation of a full-screen magnifier that uses Microsoft DirectX Overlays. This approach leads to a robust magnifier that has a low computational overhead. The magnifier has problems with video cards that use a YUV color model but these problems may be addressed by RGB to YUV translation software--an issue that is still to be investigated. The magnifier also has problems when the generic device driver, rather than the manufacturer's device driver, is installed on the system. The paper presents two further strategies for full screen magnification, namely, using multimonitor support and true type fonts for text enlargement.

Algorithms↗