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bitmapped graphics

07 Nov

Pictures which are viewed on digital devices are made up of pixels(picture elements). A pixel is the smallest unit of picture which can be controlled.Pixels are normally arranged in a two-dimensional grid and are often represented by dots or squares. To represent a black and white image, it will be stored in 2 bits, 1 being black and 0 being white. Although what would happen if the picture was in colour? It would be stored using more bits per pixel.

The resolution determines the quality of the image. So the smaller the pixels the greater the resolution.

There are two types of graphic, bitmapped and vector.

Bitmapped Graphics.
Bitmapped graphics are stored in a two dimensional grid (array) using binary to represent the colours of the pixels. Each pixel is represented by the same number of bits.

For black and white, each pixel is represented by one bit. Black = 1 and white = 1.

For colour, each pixel will be represented by the amount of bits required. For example, if there are four colours (black, white, red and green), each pixel would be represented as 2 bits.

00 = Black

01 = White

10 =  Red

11 = Green

Vector Graphics

Vector graphics  are objects such as geometrical shapes which are stored as mathematical equations which contain attributes of how they are to be drawn.

The computer will automatically save the new attributes if the object if :

-it is moved around the screen

-it is resized

– the fill pattern is changed

-the line thickness is changed

When using vector graphics, it is not possible to change the colour if the object or delete part of the object.

 

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Posted by on November 7, 2011 in Computing

 

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