This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (December 2009)

Motion blur is the apparent streaking of rapidly moving objects in a still image or a sequence of images such as a movie or animation. It results when the image being recorded changes during the recording of a single frame, either due to rapid movement or long exposure.

Applications of motion blur[link]

Photography[link]

An example of motion blur showing a London bus passing a telephone box in London

When a camera creates an image, that image does not always represent a single instant of time. Because of technological constraints or artistic requirements, the image may represent the scene over a period of time. As objects in a scene move, an image of that scene must represent an integration of all positions of those objects, as well as the camera's viewpoint, over the period of exposure determined by the shutter speed. In such an image, any object moving with respect to the camera will look blurred or smeared along the direction of relative motion. This smearing may occur on an object that is moving or on a static background if the camera is moving. In a film or television image, this looks natural because the human eye behaves in much the same way.

Early example of motion blur

Because the effect is caused by the relative motion between the camera, and the objects and scene, motion blur may be avoided by panning the camera to track those moving objects. In this case, even with long exposure times, the objects will appear sharper, and the background more blurred.

[edit] Animation

Two animations rotating around a figure, with motion blur (left) and without

In computer animation (2D or 3D) it is computer simulation in time and/or on each frame that the 3D rendering/animation is being made with real video camera during its fast motion or fast motion of "cinematized" objects or to make it look more natural or smoother.

Without this simulated effect each frame shows a perfect instant in time (analogous to a camera with an infinitely fast shutter), with zero motion blur. This is why a video game with a frame rate of 25-30 frames per second will seem staggered, while natural motion filmed at the same frame rate appears rather more continuous. Many next generation video games feature motion blur, especially vehicle simulation games.

Some of the more known games that utilise this are the recent Need for Speed titles, Unreal Tournament III, The Legend of Zelda: Majora's Mask and many others. When used in videogames, there are generally two methods used to achieve motion blur: cheaper full-screen effects, which typically only take camera movement (and sometimes how fast the camera is moving in 3-D Space to create a radial blur) into mind, and more "selective" or "per-object" motion blur, which typically uses a shader to create a velocity buffer to mark motion intensity for a motion blurring effect to be applied to or uses a shader to perform geometry extrusion.

In pre-rendered computer animation, such as CGI movies, realistic motion blur can be drawn because the renderer has more time to draw each frame. Temporal anti-aliasing produces frames as a composite of many instants.

Motion lines in cel animation are drawn in the same direction as motion blur and perform much the same duty. Go motion is a variant of stop motion animation that moves the models during the exposure to create a less staggered effect.

Computer graphics[link]

In 2D computer graphics, motion blur is an artistic filter that converts the digital image^[1]/bitmap^[2]/raster image in order to simulate the effect. Many graphical software products (e.g. Adobe Photoshop or GIMP) offer simple motion blur filters. However, for advanced motion blur filtering including curves or non-uniform speed adjustment, specialized software products are necessary.^[3]

Biology[link]

When an animal's eye is in motion, the image will suffer from motion blur, resulting in an inability to resolve details. To cope with this, humans generally alternate between saccades (quick eye movements) and fixation (focusing on a single point). Saccadic masking makes motion blur during a saccade invisible. Similarly, smooth pursuit allows the eye to track a target in rapid motion, eliminating motion blur of that target instead of the scene.

Negative effects of motion blur[link]

In televised sports, where conventional cameras expose pictures 25 or 30 times per second, motion blur can be inconvenient because it obscures the exact position of a projectile or athlete in slow motion. For this reason special cameras are often used which eliminate motion blurring by taking rapid exposures on the order of 1/1000 of a second, and then transmitting them over the course of the next 1/25 or 1/30 of a second. Although this gives sharper slow motion replays it can look strange at normal speed because the eye expects to see motion blurring and does not.

Sometimes, motion blur can be removed from images with the help of deconvolution.

Restoration[link]

An example of blurred image restoration with Wiener deconvolution:

From left: original image, blurred image and de-blurred image. Notice some artifacts in de-blurred image.

References[link]

1. ^ Motion Blur Effect, TutorialsRoom
2. ^ Photoshop - Motion Blur, tizag.com
3. ^ Traditional motion blur methods, virtualrig-studio.com

Gallery[link]

• 

  Motion blur is frequently employed in sports photography (particularly motor sports) to convey a sense of speed. To achieve this effect it is necessary to use a slow shutter speed and pan the lens of the camera in time with the motion of the object

• 

  Taken aboard an airplane turning above San Jose at night. The city lights form concentric strips.

• 

  The traffic on this street leaves brilliant streaks due to the low shutter speed of the camera and the cars' relatively fast speed.

• 

  A baby waving her arms violently up and down.

• 

  Strickland Falls in Tasmania, Australia, taken using a neutral density filter. ND filters reduce light of all colors or wavelengths equally, allowing an increase in aperture and decrease in shutter speed without overexposing the image. To create the motion blur seen here, the shutter must be kept open for a relatively long time, making it necessary to reduce the amount of light coming through the lens.

• 

  Long exposure photograph of moths showing exaggerated rod effect.

W. W. Norton & Company is an independent American book publishing company based in New York City. It has been owned wholly by its employees since the early 1960s. The company is well known for its "Norton Anthologies" (particularly the Norton Anthology of English Literature) and its texts in the "Norton Critical Editions" series, the latter of which are frequently assigned in university literature courses.

History[link]

W. W. Norton & Company is the largest American book publishing company that has remained independent since its founding. It is the oldest and largest employee-owned publisher in the United States^[1] of fiction, nonfiction, poetry, college textbooks, cookbooks, art books, and professional books.^[2] The roots of the company date back to 1923.^[1] Since the 1950s Norton's college textbook line has expanded to include leading titles in economics, government, history, music, psychology, political science, sociology, and many other academic subjects. Several of its college textbooks, including The Norton Shakespeare, The Enjoyment of Music, A History of Western Music, and new and revised entries in the Norton Anthology and Norton Critical Edition series, have become best sellers in the academic fields. The Norton Professional Books division was founded in 1985 with a line of psychotherapy volumes, expanding to include neuroscience, education, architecture, and design books.

Norton acquired Liveright (the successor to the famous Boni & Liveright publishing house) in 1974 and Countryman Press (New England travel book publisher) in 1996.

Best Sellers[link]

Norton's best-selling trade books  include Helter Skelter by Vincent Bugliosi and Curt Gentry; Jared Diamond’s Pulitzer Prize-winning best-seller Guns, Germs, and Steel; Pulitzer prize-winning historians Annette Gordon-Reed and Edmund S. Morgan's works; Patrick O'Brian’s critically acclaimed naval adventures; the works of National Book Award-winning fiction author Andrea Barrett; "Khruschev: The Man and His Era" by William Taubman; "Hitler: Hubris" and "Hitler: Nemesis" by Ian Kershaw; Liar's Poker, Moneyball, The Blind Side and The Big Short by Michael Lewis; Fareed Zakaria’s The Future of Freedom; Sebastian Junger’s The Perfect Storm; Sam Harris’s The End of Faith; The Death of Vishnu by Manil Suri; A Clockwork Orange by Anthony Burgess; The Red Book by Carl Jung; The Book of Genesis Illustrated by R. Crumb; and others in several subject fields. In the social sciences and science Norton has published best-selling books by such authors as economists Paul Krugman and Joseph Stiglitz, paleontologist Stephen Jay Gould, physicist Richard Feynman, and historians Peter Gay, Jonathan Spence, Eric Foner, Christopher Lasch, and George F. Kennan.

Distribution[link]

Norton currently distributes books for several independent publishers,^[3] including:

• Atlas & Co., publisher of contemporary and historical fiction, nonfiction, history, and biography.
• Blue Guides, travel and cultural guide books in English.
• Countryman Press, acquired by Norton in 1996, is a publisher of travel guides, New England regional interest and history, and cookbooks.
• Dalkey Archive Press, publisher of the Review of Contemporary Fiction and literature, memoirs, and criticism from around the globe.
• Fantagraphics Books, which publishes graphic fiction and comics.
• Foreign Affairs Books, publisher of political science and current affairs books.
• George Braziller Inc., publisher of art and photography books, poetry, literature, and history.
• Kales Press, publisher of nonfiction such as science, history, art, and memoir.
• New Directions Publishing, which focuses on publishing literature in translation, poetry, and recent classics.
• Odyssey Publications, Hong Kong-based publisher of cultural travel guides and history/photo books on unusual and exotic locations around the world.
• Ontario Review Books, publisher of review books.
• Peace Hill Press, publisher of secular home-schooling books and supplemental materials on history, reading, and religion.
• Pegasus Books, publishing nonfiction, history, health, biography, and mystery titles.
• Persea Books, publishing fiction, poetry, and memoirs from the United States and around the world.
• Pushcart Press, publisher of the annual Pushcart Prize literary anthologies and other books of literature and memoir.
• Quantuck Lane Press, publisher of "beautiful books of photography, art, and the eccentric, whether illustrated or not."^[4]
• Skyhorse Publishing, books on sports, fly fishing, nature, history, narrative nonfiction, military history, gambling, business, and humor titles.
• Thames & Hudson, publisher of illustrated books in art, architecture, anthropology, fashion, graphic design, photography, and travel.
• Verso Books, self-described "largest radical publisher in the English-language world".^[5]

References[link]

External links[link]

• Official Homepage
• Making the Cut - Chronicle of Higher Education