digplanet beta 1: Athena
Share digplanet:

Agriculture

Applied sciences

Arts

Belief

Business

Chronology

Culture

Education

Environment

Geography

Health

History

Humanities

Language

Law

Life

Mathematics

Nature

People

Politics

Science

Society

Technology

Example of a photograph in JPEG format (24-bit color or 16.7 million colors) before posterization, contrasting the result of saving to GIF format (256 colors). Posterization occurs across the image, but is most obvious in areas of subtle variation in tone.
Posterized photo of a hibiscus.

Posterization of an image entails conversion of a continuous gradation of tone to several regions of fewer tones, with abrupt changes from one tone to another. This was originally done with photographic processes to create posters. It can now be done photographically or with digital image processing, and may be deliberate or may be an unintended artifact of color quantization.

Cause[edit]

The effect may be created deliberately, or happen accidentally. For artistic effect, most image editing programs provide a posterization feature, or photographic processes may be used.

Unwanted posterization, also known as banding, may occur when the color depth, sometimes called bit depth, is insufficient to accurately sample a continuous gradation of color tone. As a result, a continuous gradient appears as a series of discrete steps or bands of color — hence the name. When discussing fixed pixel displays, such as LCD and plasma televisions, this effect is referred to as false contouring.[1] The result may be compounded further by an optical illusion, called the Mach band illusion, in which each band appears to have an intensity gradient in the direction opposing the overall gradient. This problem may be resolved, in part, with dithering.

Photographic process[edit]

Posterization is a process in photograph development which converts normal photographs into an image consisting of distinct, but flat, areas of different tones or colors. A posterized image often has the same general appearance, but portions of the original image that presented gradual transitions are replaced by abrupt changes in shading and gradation from one area of tone to another. Printing posterization from black and white requires density separations, which one then prints on the same piece of paper to create the whole image. Separations may be made by density or color, using different exposures. Density Separations may be created by printing three prints of the same picture, each at a different exposure time that will be combined for the final image.

Applications[edit]

Typically, posterization is used for tracing contour lines and vectorizing photo-realistic images. This tracing process starts with 1 bit per channel and advances to 4 bits per channel. As the bits per channel increases, the number of levels of lightness a color can display increases.

A visual artist, faced with line art that has been damaged through JPEG compression, may consider posterizing the image as a first step to remove artifacts on the edges of the image.

Posterizing time [edit]

Temporal posterization is the visual effect of reducing the number of frames of video, while not reducing the speed at which it actually plays. This compares to regular posterization, where the number of individual color variations is reduced, while the overall range of colors is not. The motion effect is similar to the effect of a flashing strobe light, but without the contrast of bright and dark. Unlike a pulldown, the unused frames are simply discarded, and it is intended to be apparent (longer than the persistence of vision that video and motion pictures normally depend on). An animated GIF often looks posterized because of its normally-low frame rate.

More formally, this is downsampling in the time dimension, as it is reducing the resolution (precision of the input), not the bit rate (precision of the output, as in posterization).

The resulting stop-go motion is a temporal form of jaggies; formally, a form of aliasing. This effect may be the intention, but to reduce the frame rate without introducing this effect, one may use temporal anti-aliasing, which yields motion blur.

Compare with time stretching, which adds frames.

See also[edit]

References[edit]

  1. ^ "HDTV World Glossary". CNET Networks. 2007. Retrieved 2007-06-06. 

External links and sources[edit]

  • Source: Langford, Michael. The Darkroom Handbook. New York: Dorling Kindersley Limited, 1981. 245-249.
  • Source: Jasc Software. Paint Shop Pro Help, 1998.

Original courtesy of Wikipedia: http://en.wikipedia.org/wiki/Posterization — Please support Wikipedia.
This page uses Creative Commons Licensed content from Wikipedia. A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia.
31815 videos foundNext > 

Top 10 Posterizing Dunks of the 2012-2013 season!

Check out the ten best facials of the season with our Top 10 Posterizing Dunks countdown! About the NBA: The NBA is the premier professional basketball leagu...

Ballislife POSTERIZED Vol. 1!! NASTIEST In-Game Dunks Since 2006!! INSANE Highlights!!!

Check out arguably the BEST Ballislife mixtape to date,"'Ballislife POSTERIZED Vol. 1". This 4 minute mixtape features the NASTIEST in-game dunks and posteri...

Griffin's Montage of Posterization

Check out this recap of all the big time, posterizing slam dunks by Blake Griffin over his career so far as he.

NBA's Greatest Posterizing Dunks of all time!

Go watch part 2! https://www.youtube.com/watch?v=OmRBcM5Ursw.

NBA: All-Decade Best: Regular Season Posterization

Posterize

Hi. In this tutorial I am going to show how to do some cool effects using Posterize in Photoshop.

LeBron James Top 20 Posterize Dunks 2003-2013

Check out the Best Posterize Dunks of Lebron James's NBA career 2003-2013 Absolutely Amazing ! All rights belongs to NBA.

Funny Posterization Video

That feeling when you posterize someone. That Feeling When You Completely Destroy Someone In Basketball!

LeBron James MANLY Freight Train Dunk Posterization Over Jason Terry-Heat vs Celtics 3/18/13

NBA LeBron James show off his tremendous athleticism. He takes a lob pass and dunks over Jason Terry who hits the floor hard in the process of trying to defe...

Stencilizer for posterization

How to use the Stencilizer web app to posterize photos as part of the process to sketch them with a digital diecutter. Full tutorial at http://cleversomeday....

31815 videos foundNext > 

27 news items

Yahoo Sports (blog)

Yahoo Sports (blog)
Thu, 21 Aug 2014 09:31:50 -0700

The most vicious acts of posterization carry a fundamental indecency. They endure not just because of great feats of athleticism, but because there is a sense that the dunker has sized up the dunkee and essentially robbed him of his pride and good name.

Rant Sports

Rant Sports
Wed, 27 Aug 2014 06:30:00 -0700

While Vince Carter might not be the most popular former Toronto Raptors player, there is no question that in his prime, he was the greatest player in franchise history. Arguably the greatest in-game dunker of all time, Carter was also a valuable ...
 
PC Magazine
Fri, 22 Aug 2014 06:29:35 -0700

I also noticed posterization, the tendency for sudden shifts in color or tone where they should be gradual, in many scenes. Audio from the MW665's two single-watt speakers is soft, and best for a small room or if you're close to the projector. Related ...
 
Adorama (press release) (blog)
Sun, 17 Aug 2014 21:02:04 -0700

Picture Effects and Creativity: The Sony A5100 has 13 Picture Effects: Posterization (Color), Posterization (B/W), Pop Color, Retro Photo, Partial Color (R/G/B/Y), High Contrast Monochrome, Toy Camera(Normal/Cool/Warm/Green/Magenta), Soft High-key ...
 
PC Magazine
Thu, 31 Jul 2014 07:30:46 -0700

In fact, rainbow artifacts were more apparent in the NP-M322X's video than in all but a few DLP projectors I've tested. Even someone slightly sensitive to the effect will likely be bothered by it. I saw other issues such as posterization (abrupt shifts ...
 
Mountain West Connection
Thu, 31 Jul 2014 12:22:00 -0700

... passes from his highlight reel and you can just imagine what Shepard, Spencer, or Chol might do on the receiving end. His junior season mix tape in no way disappoints, featuring juicy jams, delicious dimes, and the occasional posterization. Just ...
 
Lakers Nation
Wed, 06 Aug 2014 15:09:59 -0700

As a part of Lin's Fan Appreciation Week, the star floor general posted a video on his Instagram account of him posterizing his mother in the kitchen. Lin apologized to his mother for the posterization by simply using the hashtag, #sorrymom, on his ...

Rappler

Rappler
Sat, 16 Aug 2014 06:12:40 -0700

MANILA, Philippines - Gilas Pilipinas opened their 2014 Antibes International Basketball Tournament campaign in Antibes, France by taking on the French national basketball team on Saturday morning, August 16 (PH time). Though the Philippine national ...
Loading

Oops, we seem to be having trouble contacting Twitter

Talk About Posterization

You can talk about Posterization with people all over the world in our discussions.

Support Wikipedia

A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia. Please add your support for Wikipedia!