The Digital Revolution Changing information

What is Digital?  Discrete values used for  Input  Processing  Transmission  Storage  Display  Derived from digit  Not analog  Discrete values used for  Input  Processing  Transmission  Storage  Display  Derived from digit  Not analog

Analog Signals  Continuous  Frequency  Amplitude  Small variations significant  Disadvantage - noise  Analog computers  Continuous  Frequency  Amplitude  Small variations significant  Disadvantage - noise  Analog computers

Why Digital?  Analog  Sound and light waves  Continuous waveforms  Digital  Describe sound and light as a string of binary data representations (1s and 0s)  Provides exact reproduction of sounds and color  Analog  Sound and light waves  Continuous waveforms  Digital  Describe sound and light as a string of binary data representations (1s and 0s)  Provides exact reproduction of sounds and color

Analog-to-Digital Conversion

Sampling Rate  Sample - numeric representation of wave  Rate - how many samples taken in a specific time period  Wave values between sample interpolated  Typical sampling rates 44.1 kHz to 48 kHz  Sample - numeric representation of wave  Rate - how many samples taken in a specific time period  Wave values between sample interpolated  Typical sampling rates 44.1 kHz to 48 kHz

Digital Images  Pixels  Resolution  Color depth  4 bits - 16 colors  8 bits colors  bits - true color  Pixels  Resolution  Color depth  4 bits - 16 colors  8 bits colors  bits - true color

Original Computer Monitors  Using only 1 bit to store color, original computer monitors used only two colors

Early Computer Graphics  Early computer graphics only used four colors at any one time

More bits - More Color  As technology advanced, computer monitors could display 16 colors at one time  Next came 256 colors  As technology advanced, computer monitors could display 16 colors at one time  Next came 256 colors

Real color  24 bits - 16 million colors  Called true color  32 bits - adds transparency  24 bits - 16 million colors  Called true color  32 bits - adds transparency

Raster Graphics vs. Vector Graphics  Raster graphics - painting pixels  Vector graphic - uses objects  Raster graphics - painting pixels  Vector graphic - uses objects

Enhancing Photos and Adding Special Effects  Image-editing software  Types of enhancement  Redeye removal  Crop  Correct color balance  Filtering effects  Image-editing software  Types of enhancement  Redeye removal  Crop  Correct color balance  Filtering effects DabbleEmbossRippleOriginal Click to see various photo effects

Digital Video  Combines digital images with digital sound  Two types  Interlaced  Progressive scan  Reduces cost of film creation  Copes good as original  Combines digital images with digital sound  Two types  Interlaced  Progressive scan  Reduces cost of film creation  Copes good as original

Data Compression  Encoding information using fewer bits  Goal - reduce file size  Lossless Compression  Lossy Compression  All compression leads to data loss  Encoding information using fewer bits  Goal - reduce file size  Lossless Compression  Lossy Compression  All compression leads to data loss

Digital Technology  Media Integrity  Media Integration  Flexible Interaction  Transactions  Tailoring  Editing  Media Integrity  Media Integration  Flexible Interaction  Transactions  Tailoring  Editing

What’s the results?  Information Age  Digital Revolution  Information Economy  Better and cheaper access to knowledge  Information Age  Digital Revolution  Information Economy  Better and cheaper access to knowledge