1 / 24

Representing Information Digitally

Representing Information Digitally. Digitization. Initially transforming data for computer use Assigning people social security numbers The creation of telephone numbers Encoding information became the way to transform the real world into a context that the computer could understand.

lamond
Télécharger la présentation

Representing Information Digitally

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Representing Information Digitally

  2. Digitization • Initially transforming data for computer use • Assigning people social security numbers • The creation of telephone numbers • Encoding information became the way to transform the real world into a context that the computer could understand

  3. Information Metamorphosis • Fitting the real world into the computer • Computer’s world • Electronic • Fast • Binary • Real World • Multiple forms of data / information • Imprecise / vague • Non uniform speeds

  4. Information Metamorphosis • Real World Data Forms • Numeric Data • Character Data • Graphical / Visual Data • Audio Data • Instructional Data • Methodology needed to transform real world data into computer world (binary)

  5. Binary Number System • A decimal number: 1,648,319 • A binary number: 1001 1101

  6. Binary Number System • Binary for numeric data • Binary digit = Bit • 8 Bits = Byte • Smallest addressable unit within the computer • 4 Bytes = Word • Basic unit for arithmetic • Contains 32 bits • Converting from binary

  7. Numeric Data

  8. Numeric Data • Converting to binary • Repeated division by 2 • Remainders are the important part • Read from bottom up as if left to right

  9. Character Data • Binary for Character Data • 8 bit combinations assigned to a symbol • Name for mapping process is ASCII table

  10. ASCII, The American Standard Code for Information Interchange

  11. Graphical Data • Binary for Graphical Data

  12. Graphical Data • Binary for Graphical Data

  13. Graphical Data • Binary for Graphical Data • Each black pixel is represented as a “1” • Each white pixel is represented as a “0” • Pixels are grouped in units of 8 so they can be stored in 1 byte

  14. Graphical Data A 1” picture scanned at 150 DPI (dots per inch) Total size = 150 X 150  22,500 dots Memory required = 22,500 / 8  2,813 bytes Color requires more bits to represent each dot Using 8 bits for each dot allows for 256 different colors The 1” picture now requires 22,500 bytes

  15. Graphical Data • Printers are rated in DPI for print quality • Scanners are rated in DPI for image resolution • Monitors / displays have display settings for display resolution • 800 X 600 • 1024 X 768 • 1280 X 1024 • 1400 X 1050

  16. Audio Data • Binary for audio data • Sound as a waveform • Y-axis represents voltage • X-axis represents time • Suppose the wave form shown represents 1 second of sound

  17. Audio Data • Divide Sample into segments

  18. Audio Data • Divide Sample into more segments

  19. Audio Data • Divide Sample into even more segments

  20. Audio Data • The more segments the better the re-created wave form • The given sample was divided into 34 segments (approx) • An Audio CD utilizes 44,000 samples per second of sound

  21. Instructional Data • Binary for Instructional Data • Instructional Data has not only content but sequence • Driving directions to NJ Aquarium • Designated number of steps • Sequence of steps is critical to success • Rearranging sequence will not get you to the NJ Acquarium • Recipe / Directions / Program

  22. Instructional Data • Word Hunt Instruction Set • Similar to “decoder ring” • Six instructions • GOTO # • SELECT # • FORWARD # • BACKUP # • WRITE • STOP

  23. Instructional Data • A program is a collection of instructions • Executing the program means to “carry out” the listed instructions • GOTO# - turn to designated page • SELECT# - count down this many lines • FORWARD# - count in this many words

  24. Instructional Data • Real computers have different types of instructions • Arithmetic • Data Movement • Logical / Comparison • Control • Input / Output

More Related