Computers Seeing People

By Essa, Irfan A. | AI Magazine, Summer 1999 | Go to article overview

Computers Seeing People


Essa, Irfan A., AI Magazine


Building machines that can see has been one of the most exciting and challenging research quests of the last 30 years. Much effort has been expended on "automatic deduction of structure of a possibly dynamic three-dimensional world from two-dimensional images" (Nalwa 1993). There has been considerable progress in the areas of object recognition, image understanding, and scene reconstruction from single and multiple images. This progress, coupled with the improvements in computational power, has prompted a new research focus of making machines that can see people; recognize them; and interpret their gestures, expressions, and actions. In this article, I present methods that give machines the ability to see people, understand their actions, and interact with them. I present the motivating factors behind this work, examples of how such computational methods are developed, and their applications.

The basic reason for providing machines the ability to see people really depends on the task we associate with a machine. An industrial vision system aimed at extracting defects on an assembly line need not know anything about people. Similarly, a computer used for e-mail and text writing need not see and perceive the user's gestures and expressions. However, if our interest is to build intelligent machines that can work with us, support our needs, and be our helpers, then these machines should know more about who they are supporting and helping. If our computers are to do more than support out text-based needs such as writing papers, creating spreadsheets, and communicating by e-mail, perhaps taking on the role of being a personal assistant, then the ability to see a person is essential. Such an ability to perceive people is something that we take for granted in out everyday interactions with each other. This ability to perceive people and interact with them naturally is essential as we move toward building machines like HAL in 2001: A Space Odyssey and Commander Data in Star Trek: The Next Generation.

At present, our model of a machine, or more specifically of a computer, is something that is placed in the corner of the room. It is deaf, dumb, and blind and has no sense of the environment around it or of a person near it. We communicate with this computer using a coded sequence of tappings on a keyboard. Imagine a computer that knows you are near it, knows you are looking at it, and knows who you are and what you are trying to do. Such abilities in a computer are hard to imagine, unless it has an ability to perceive people. Research in speech recognition has made considerable progress toward perception of human speech (see Cole et al. [1995] for a survey). Commercial systems capable of word spotting and recognition of continuous speech are now available. Analysis of the video signal to perceive people has become a challenging and exciting research avenue for the field of computer vision, resulting in significant progress in the recent years.

To make machines that see people, the computer must first determine if someone is near it (where) and count how many people are in its field of view. The next step is to identify who the people are. After the computer has identified the people, it can interpret facial expression, hand gestures, and body language to determine what the people want or are doing in the scene and why. In the upcoming sections, I present the approaches to determine where, how many, who, what, and why with reference to people in a scene. The answer to each question is not possible independently, and each question depends on the other as dictated by the situation. Before getting into details, I briefly discuss the applications of such a technology.

Applications

Applications of computer vision methods aimed specifically at seeing people are many and encompass several different areas.

Effective human-computer interaction (HCI): Imagine computers that interact with you as we interact with each other, using speech and gestures. …

The rest of this article is only available to active members of Questia

Sign up now for a free, 1-day trial and receive full access to:

  • Questia's entire collection
  • Automatic bibliography creation
  • More helpful research tools like notes, citations, and highlights
  • A full archive of books and articles related to this one
  • Ad-free environment

Already a member? Log in now.

Notes for this article

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items

Items saved from this article

This article has been saved
Highlights (0)
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

Citations (0)
Some of your citations are legacy items.

Any citation created before July 30, 2012 will labeled as a “Cited page.” New citations will be saved as cited passages, pages or articles.

We also added the ability to view new citations from your projects or the book or article where you created them.

Notes (0)
Bookmarks (0)

You have no saved items from this article

Project items include:
  • Saved book/article
  • Highlights
  • Quotes/citations
  • Notes
  • Bookmarks
Notes
Cite this article

Cited article

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

1

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited article

Computers Seeing People
Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this article

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Help
Full screen

matching results for page

    Questia reader help

    How to highlight and cite specific passages

    1. Click or tap the first word you want to select.
    2. Click or tap the last word you want to select, and you’ll see everything in between get selected.
    3. You’ll then get a menu of options like creating a highlight or a citation from that passage of text.

    OK, got it!

    Cited passage

    Style
    Citations are available only to our active members.
    Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

    1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

    Cited passage

    Thanks for trying Questia!

    Please continue trying out our research tools, but please note, full functionality is available only to our active members.

    Your work will be lost once you leave this Web page.

    For full access in an ad-free environment, sign up now for a FREE, 1-day trial.

    Already a member? Log in now.