Analog to Digits

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Analog to Digits
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Information

• Information comes in many forms

• Words, Numbers, Pictures, Sounds

• Computers only understand information in digital
  form
• Information must be broken into bits

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Bits, Bytes, and Buzzwords

• Common terms might describe file size or memory
  size

• Bit smallest unit of information (1 or 0)
• Byte a grouping of eight bits of information
  (11010100)

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Bits as Codes

• ASCII - American Standard Code for Information
  Interchange
• most widely used code, represents each character
  as a unique 8-bit code.

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ASCII American Standard Code for Information Inter
change
most widely used code, represents each character
as a unique 8-bit code.
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(No Transcript)
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Thats one small step for man, one giant leap
for mankind
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Encoding text

• ASCII character set
• Assigns numbers to letters
• 7 bits 128 I s the standard ASCII
• 8 bits 256 possible characters ( only need about
  150)
• A is 65 and a is 97
• is 36
• Bell is 7
• 16 bit character set (65,000 possible
  characters)
• An extension will include as many as a million
  characters

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Encoding text

• Unicode
• 16 bit character set (65,000 possible
  characters)
• a unique number for every character,no matter
  what the platform,no matter what the program,no
  matter what the language.
• For the principal written languages
• Includes Chinese with its more than 13,000
  characters of normal use (50,000 total characters)

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Unicoded Language sets

• Latin, Greek, Cyrillic, Armenian, Hebrew, Arabic,
  Devanagari, Bengali, Gurmukhi, Gujarati, Oriya,
  Tamil, Telugu, Kannada, Malayalam, Thai, Lao,
  Georgian, Tibetan, Japanese

• Kana, modern Korean Hangul
• a unified set of Chinese/Japanese/Korean (CJK)
  ideographs. Ethiopic, Canadian Syllabics,
  Cherokee, additional rare ideographs, Sinhala,
  Syriac, Burmese, Khmer, and Braille.

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The Binary System

• The first 256 codes are the ASCII codes, then
  follows sections of other character sets

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Unicode Standard

• does not define glyph images.
• defines how characters are interpreted, not how
  glyphs are visually displayed
• The software or hardware-rendering engine of a
  computer is responsible for the appearance of the
  characters on the screen.
• The Unicode Standard does not specify the size,
  shape, nor orientation of on-screen characters.

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Bits as Instructions

• The computer stores programs as collections of
  bits.
• For instance, 01101010 might instruct the
  computer to add two numbers.

• Other bit instructions might include where to
  find numbers stored in memory or where to store
  them.

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The Binary System

• Now that we have discussed the binary system, you
  will understand the statement
• There are 10 kinds of people in this world.
• Those who understand the binary system
• and those who dont

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Analog sound and pictures
Chemically developed pictures have continuous
shades and color

• A violins notes are continuous

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Digitizing Images

• Images are digitized using a two step process
• 1. Sampling the continuous tone image into pixels
• 2. Quantifying the pixels by assigning a number
  to each pixel

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Sampling

• The image is broken up into a grid of cells.
• These cells are called Picture Elements
• Better known as Pixels
• The number of rows and columns is the resolution
• This one is 40 X 80

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Sampling

• Before one number can be assigned to a pixel,
  there must be one color for each pixel
• Pixel samples are averaged

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Quantifying
Stored as
1111 1110 1100 1010 1000 1001

• Each pixel is assigned the number of the
  associated shade.
• This image uses a 4 bit code for the shades of
  gray

0 1 2 3 4 5
6 7 8 9 10
11 12 13 14 15
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Example Digitizing Images

• Color images require a much larger file
• Each pixel has not only color, but shade,and
  intensity
• Or for Monitors mixture of Red, Green and Blue

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Three bytes for each color pixel
11111111 10000000 10000000
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Monitor vs Image Pixels
One image pixel could be composed of many screen
pixels
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Thats all folks!