Part of the Multimedia and graphics glossary:

Moiré effect is a visual perception that occurs when viewing a set of lines or dots that is superimposed on another set of lines or dots, where the sets differ in relative size, angle, or spacing. The moiré effect can be seen when looking through ordinary window screens at another screen or background. It can also be generated by a photographic or electronic reproduction, either deliberately or accidentally.

The illustration below shows two sets of lines of equal thickness and equal spacing, but one set is angled at a few degrees while the other set runs vertically. The moiré effect in this case appears as a set of thick, ill-defined, nearly horizontal bars.

moire.gif (7956 bytes)

Moiré effect can produce interesting and beautiful geometric patterns. However, the phenomenon degrades the quality and resolution of graphic images. Problems occur when a screened image, such as is found in a newspaper, is directly photographed and then the photograph is reprinted in screened format. It can also occur when the image from a computer display is reproduced by photographic means and then rendered in a screened or dot-matrix format. The fine matrix of dots in the original image almost invariably conflicts with the matrix of dots in the reproduction. This generates a characteristic criss-cross pattern on the reproduced image.

The word moiré is French (from the past participle of the verb moirer, meaning to water) and can be written with or without an accent aigu on the final "e." It was originally used to describe an effect applied to silk material to give it a wavy or rippled texture.

This was last updated in September 2005
Contributor(s): Karsten Farley
Posted by: Margaret Rouse

Related Terms

Definitions

  • AMOLED (active matrix OLED)

    - AMOLED (Active Matrix OLED) is a screen technology based on pixels made of tiny red, blue and green organic material-based light emitting diodes. Since the three colors in the pixels themselves are... (WhatIs.com)

  • TED talk

    - A TED talk is a presentation at the main TED (technology, entertainment, design) conference or one of its many satellite events around the world. The first TED conference was in 1984; the conferenc... (WhatIs.com)

  • TED

    - The TED (technology, entertainment, design) conference is an annual gathering for presentations known as TED talks on a broad range of topics related to science and culture. The main TED conference... (WhatIs.com)

Glossaries

  • Multimedia and graphics

    - Terms related to multimedia, including graphics, animation and video definitions and words and phrases about images and sound.

  • Internet applications

    - This WhatIs.com glossary contains terms related to Internet applications, including definitions about Software as a Service (SaaS) delivery models and words and phrases about web sites, e-commerce ...

Ask a Question About moire effectPowered by ITKnowledgeExchange.com

Get answers from your peers on your most technical challenges

Tech TalkComment

Share
Comments

    Results

    Contribute to the conversation

    All fields are required. Comments will appear at the bottom of the article.