dcsimg
Main » TERM » B »

bit map

bit map

)A representation, consisting of rows and columns of dots, of a graphics image in computer memory. The value of each dot (whether it is filled in or not) is stored in one or more bits of data. For simple monochrome images, one bit is sufficient to represent each dot, but for colors and shades of gray, each dot requires more than one bit of data. The more bits used to represent a dot, the more colors and shades of gray that can be represented.

The density of the dots, known as the resolution, determines how sharply the image is represented. This is often expressed in dots per inch (dpi )or simply by the number of rows and columns, such as 640 by 480.

To display a bit-mapped image on a monitor or to print it on a printer, the computer translates the bit map into pixels (for display screens) or ink dots (for printers). Optical scanners and fax machines work by transforming textor pictures on paper into bit maps.

Bit-mapped graphics are often referred to as raster graphics. The other method for representing images is known as vector graphics or object-oriented graphics. With vector graphics, images are represented as mathematical formulas that define all the shapes in the image. Vector graphics are more flexible than bit-mapped graphics because they look the same even when you scalethem to different sizes. In contrast, bit-mapped graphics become ragged when you shrink or enlarge them.

Fonts represented with vector graphics are called scalable fonts , outline fonts , or vector fonts. The best-known example of a vector font system is PostScript. Bit-mapped fonts, also called raster fonts, must be designed for a specific deviceand a specific size and resolution.










LATEST ARTICLES
Top Cloud Computing Facts

The following facts and statistics capture the changing landscape of cloud computing and how service providers and customers are keeping up with... Read More »

SEO Dictionary

From keyword analysis to backlinks and Google search engine algorithm updates, our search engine optimization glossary lists 85 SEO terms you need... Read More »

Texting & Chat Abbreviations

From A3 to ZZZ this guide lists 1,500 text message and online chat abbreviations to help you translate and understand today's texting lingo. Read More »

STUDY GUIDES
Java Basics, Part 1

Java is a high-level programming language. This guide describes the basics of Java, providing an overview of syntax, variables, data types and... Read More »

Java Basics, Part 2

This second Study Guide describes the basics of Java, providing an overview of operators, modifiers and control Structures. Read More »

Network Fundamentals Study Guide

Networking fundamentals teaches the building blocks of modern network design. Learn different types of networks, concepts, architecture and... Read More »