Data Representation

Data Representation

1. Images

   • An image is broken down into very small elements called pixels, a pixel is one specific colour.
   • The colour depth of an image is measured in bits. The number of bits indicates how many colours are available for each pixel.
   • Each colour of an image is stored as a binary number.
   • Image size will increase as colour depth is increased
   • Metadata means 'data about data' and provides information about the image, for example file name, file format, resolution and colour depth
   • If an image's resolution is 600 x 400 then it is 600 pixels by 400 pixels.

2. Audio

   • Sound waves are analogue, which means continuously changing.
   • Anything stored on a computer has to be stored as a series of binary numbers. To store sound on a computer we need to convert the waveform into a numerical representation.
   • The device that takes real-world analogue signals and converts them to a digital representation is called an Analogue-to-Digital converter (ADC)
   • Sound quality is affected by Sample Resolution (the number of bits used to store each sample) and Sample Interval (the time period between samples/measurements taken).

3. Info or Data

   • Data can be described as the raw facts or figures
   • Information is how we present data so that it is useful or meaningful to the reader, and is often defined as processed data that has meaning and context.
   • Input devices take real-world inputs and convert them to binary code numbers, data. Data is stored, not information. Output devices take data from a computer and present it as information to the user.