Dithering
   
Home: Graphic Academy
 
Graphics Books
 
Graphics File Formats
  Animation File Formats
Bitmap File Formats
CAD File Formats
Cursor File Formats
Font File Formats
Icon File Formats
Metafile File Formats
Prepress File Formats
Vector File Formats
Video File Formats
Web File Formats
More Graphics File Formats
 
Graphics Software
  Banner Design Software
CAD Software
Diagram Drawing Software
Illustration Software
Photo Editing Software
Video Conversion Software
More Graphics Software
 
Graphics Tutorials
 
  • Adobe Dreamweaver Tutorials
  • Adobe Photoshop Tutorials
  • AutoCAD Tutorials
  • How To Draw Tutorials
    Banner Design Tutorial
    Banner Display Tutorial
    Color Combinations Tutorial
    Color-Safe Conversion Tutorial
    eBook Covers Tutorial
    Favicon Tutorial
    GIF + Photo Tutorial
    Good Web Design
    Image Slice Tutorial
    Image Tiling Tutorial
    Imagemap Tutorial
    Photography Tutorial
    Prevent Copying Tutorial
    Screenshots Tutorial
    Should I Use Flash?
    Text to Images Tutorial
    Web Image File Formats
    More Graphics Tutorials
  •  
    Graphics Glossary

    Advertisement
     
    Learn PhotoShop


    Perfect for Beginners...
    - Start immediately
    - Save time
    - Avoid confusion
    - Save effort
    - Improve creativity
    - From beginner to advanced
    Click here
     
         
    GraphicsAcademy.com  >  Glossary  >  Dithering

       

     

    Dithering

    Dithering is an imaging technique which allows a bitmap (or a bitmapped device, such as a screen or printer) to appear to display more colors than are actually possible.
    • If the bitmap (or bitmapped device) only allows black and white, dithering can be used to produce an illusion of gray.

    • If the bitmap (or bitmapped device) allows a palette of colors, then dithering can produce an illusion of more colors being displayed than are in the palette.
    Let's look at some examples (on the left I show a zoomed in section of bitmap, on the right I show a larger section of bitmap at actual size.

    Using black and white to produce the illusion of light gray:

    Zoomed In
    25% Black, 75% White
      Actual Size
    Dithered Image
       

    Using black and white to produce the illusion of a mid gray:

    Zoomed In
    50% Black, 50% White
      Actual Size
    Dithered Image
       

    Using black and white to produce the illusion of a dark gray:

    Zoomed In
    75% Black, 25% White
      Actual Size
    Dithered Image
       

    Using red and yellow to produce the illusion of a orange:

    Zoomed In
    50% Red, 50% Yellow
      Actual Size
    Dithered Image
       

    While dithering can be an effective technique for making an image look as if it has more colors than actually does, there are a number of issues with dithering:
    1. Dithering can produce the illusion of patterns within the colored areas. This can be a significant problem when dithering images containing naturalistic images (for example, photographs), and tends to be particularly noticeable when dithering is used on relatively low resolution devices.

      There are various methods of dithering available - and which is best in each case depends on the content of image, and of course, personal taste.

      Shown below is a color image that has been converted to monochrome using some different dithering methods:

      Original Image:
      Original image
      Ordered Dithering:
      Image converted to monochrome using Ordered Dithering

      Jarvis Dithering:
      Image converted to monochrome using Jarvis, Judice & Ninke Dithering
      Floyd-Steinberg Dithering:
      Image converted to monochrome using Floyd-Steinberg Dithering

      Stucki Dithering:
      Image converted to monochrome using Stucki Dithering

      Next, we compare reducing the color depth of an image using different approaches. Shown below is a color image that has been converted from True Color to the greatly reduced color depth of color-safe palette using three different methods: no dithering, Ordered Dithering, and Floyd-Steinberg Dithering.

      Color-Safe
      (No dithering):
      Color-safe image
      Color-Safe
      (Ordered Dithering):
      Color-safe image created using Ordered Dithering

      Color-Safe
      (Jarvis Dithering):
      Color-safe image created using Jarvis, Judice & Ninke Dithering
      Color-Safe
      (Floyd-Steinberg Dithering):
      Color-safe image created using Floyd-Steinberg Dithering

      Color-Safe
      (Stucki Dithering):
      Color-safe image created using Stucki Dithering

    2. Once an image has been dithered, it can be extremely hard to edit.

      For example, if we had an image which contained areas that had been dithered (like the examples above) to produce orange and various shades of gray, there is no simple way to adjust the color of those areas, because each area contains a mix of pixels of different colors.

      As a result, in an ideal world, images would be prepared and stored in full color, and then only dithered when displayed/printed on a device which did not support all the necessary colors. However, in the real world, the limitations of networks, storage, memory, and graphics file formats, frequently means that despite this significant disadvantage, images are often prepared and stored already dithered.

    3. Dithered images contain lots of fine detail that may not compress well, particularly in file formats that use LZW or Run-length Compression.

      As a result, in some cases, it may actually take less storage and bandwidth to store and transmit images in full True Color, and allow the output device to perform any necessary dithering upon receiving this image. An example where this may occur, is if web publishing images in the PNG file format.
    As mentioned above, there are many methods of dithering. These include:

    Discuss Dithering


       

    Please feel free to post your comments:




    Related Pages on this site:
    Related Books:
    • A Visual Dictionary of Graphic Design

      Disclosure: Products details and descriptions provided by Amazon.com. Our company may receive a payment if you purchase products from them after following a link from this website.
       
      A Visual Dictionary of Graphic Design
       
        
      By Gavin Ambrose

      Brand: Fairchild Books
      Released: 2006-11-15
      Paperback (288 pages)

      • Used Book in Good Condition


      Product Description:

      The Visual Dictionary of Graphic Design is a comprehensive guide to the numerous terms used within graphic design and associated disciplines.

      Over 250 terms are explained and contextualized, with concise definitions accompanied by illustrations and examples taken from historical and contemporary graphic design.

      The dictionary covers traditional practice and process terms as well as modern terminology. It also defines a wide variety of practical terms, such as Perfect binding, Deboss and Strikethrough, as well as movements and styles including Surrealism, Psychadelia and Postmodernism.



      List Price: $22.95*
      Lowest New Price: $12.09*
      Lowest Used Price: $3.00*
      Usually ships in 24 hours*
      *(As of 23:54 Pacific 26 Jul 2017 More Info)

      Buy It Now
       


    • Computer Graphics Dictionary (Advances in Computer Graphics and Game Development Series)

      Disclosure: Products details and descriptions provided by Amazon.com. Our company may receive a payment if you purchase products from them after following a link from this website.
       
      Computer Graphics Dictionary (Advances in Computer Graphics and Game Development Series)
       
        
      By Roger Stevens

      Brand: Charles River Media
      Hardcover (460 pages)

      • Used Book in Good Condition


      Product Description:
      The popularity of special effects movies and the video game industry has introduced thousands of new terms, techniques, and software applications to both the computing professional and the general user. Unfortunately, these graphics creations represent a convergence of expertise from several different subject areas, resulting in a lack of familiarity with many terms. This unique dictionary includes over 4,000 definitions and illustrations from the computer graphics world, including those from digital filmmaking, animation, programming, mathematics, holography, photorealism, lighting, character creation, game development, modeling, and more.

      List Price: $49.95*
      Lowest New Price: $13.88*
      Lowest Used Price: $4.73*
      Usually ships in 24 hours*
      *(As of 23:54 Pacific 26 Jul 2017 More Info)

      Buy It Now
       


    • Design Speak: Bridging the Communication Gap Between Clients and Designers

      Disclosure: Products details and descriptions provided by Amazon.com. Our company may receive a payment if you purchase products from them after following a link from this website.
       
      Design Speak: Bridging the Communication Gap Between Clients and Designers
       
        
      By Anistatia R. Miller

      Brand: Rockport Publishers
      Hardcover (160 pages)

      • Used Book in Good Condition


      Product Description:
      What does a client or art director really mean when they say "I want a clean look" or "The design should be bold"? Graphic Design Speak offers the answers in an easy-to-follow format that both clients and designers can use as points of reference in design briefs or strategy meetings. This book is an essential tool for any designer seeking to gain a better knowledge of the wants and needs of their clients.

      --Over 200 color projects showing specific design solutions to answer client demands

      --An international gathering of designers, studios, and ad agencies

      --Quotes, tips, and anecdotes from both designers and clients

      List Price: $40.00*
      Lowest New Price: $29.70*
      Lowest Used Price: $3.74*
      Usually ships in 1-2 business days*
      *(As of 23:54 Pacific 26 Jul 2017 More Info)

      Buy It Now
       


    Photo Editor X Photo Editing Software



       
     
       
     
       
    Disclosure: Our company's websites' content (including this website's content) includes advertisements for our own company's websites, products, and services, and for other organization's websites, products, and services. In the case of links to other organization's websites, our company may receive a payment, (1) if you purchase products or services, or (2) if you sign-up for third party offers, after following links from this website. Unless specifically otherwise stated, information about other organization's products and services, is based on information provided by that organization, the product/service vendor, and/or publicly available information - and should not be taken to mean that we have used the product/service in question. Additionally, our company's websites contain some adverts which we are paid to display, but whose content is not selected by us, such as Google AdSense ads. For more detailed information, please see Advertising/Endorsements Disclosures

    Our sites use cookies, some of which may already be set on your computer. Use of our site constitutes consent for this. For details, please see Privacy.

    Contact Us     Privacy     Terms Of Use     Advertising/Endorsements Disclosures

    Copyright © 2005-2014, Answers 2000 Limited

    In Association With Amazon.com
    Answers 2000 Limited is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.
    In Association With Amazon.co.uk
    Answers 2000 Limited is a participant in the Amazon EU Associates Programme, an affiliate advertising programme designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.co.uk.

    CERTAIN CONTENT THAT APPEARS ON THIS SITE COMES FROM AMAZON SERVICES LLC. THIS CONTENT IS PROVIDED 'AS IS' AND IS SUBJECT TO CHANGE OR REMOVAL AT ANY TIME.
    CERTAIN CONTENT THAT APPEARS ON THIS SITE,COMES FROM AMAZON EU S. r.l. THIS CONTENT IS PROVIDED 'AS IS' AND IS SUBJECT TO CHANGE OR REMOVAL AT ANY TIME.

    All trademarks are property of their respective owners.
    All third party content and adverts are copyright of their respective owners.

    Some graphics on our web sites are Copyright (C) 1997-2000 Hemera Technologies Inc., and used under license. All such pictures are provided for viewing purposes only and are not to be saved or downloaded. All such pictures of recognizable individuals are models and used for illustrative purposes only, and not meant to imply any association or endorsement of said individual with any product or service.
     
       
    Photo Editor X Photo Editing Software