Presentation on theme: "Image and Sound Representation"— Presentation transcript

Image and Sound Representation

Image and Sound Representation

Image Representation

Images on a computer system are made up of thousands of small coloured dots, known as pixels (short for picture elements). Bitmap images are stored as an array of pixels.

A black and white bitmap image will store a 0 for a black pixel and 1 for a white pixel.

11111111
10011001
01111110
11011011
11111111
11111111
11100111
11111111
This bitmap image can be represented
using a 64 bits (or 8 bytes)

Vector graphics

• Images can be stored in different ways in computers. When you create a drawing in power point this is a vector graphic.
• Each line, circle or square is made up of simple properties such as position height and width

Bitmap graphics

• When you take a picture with a digital camera it is not made up of lines.
• To store this type of image on a computer the image is broken down into very small elements called pixels. Each pixel is set to one colour.

Each pixel can be represented as a binary number, and so a bitmap image is stored in a computer as a series of binary numbers, so that:

• a black and white image only requires 1 bit per pixel – this means that each pixel can be one of two colours, corresponding to either 1 or 0
• if each pixel is represented by 2 bits, then each pixel can be one of four colours (22 = 4), corresponding to 00, 01, 10, or 11
• if each pixel is represented by 3 bits then each pixel can be one of eight colours (23 = 8), corresponding to