Due: Thursday 11/21 10:00 am

Submission name: work24.txt

Text encoding

  • All digital data is represented as binary numbers.
  • For text, each character is assigned a number according to some agreed upon convention, called an encoding.
    • ASCII was the standard for many years.
  • In a plain text file:
    • write your first name in lowercase letters
    • Write your name is ASCII, put a space between each number
    • Convert your ASCII name to hexadecimal, using one 2 digit hexadecimal number for each letter. Put spaces between each number.
    • Convert your hexadecimal name to binary, remember that each hex digit turns into 4 binary digits. Your file may look like this: 
      jonalf
106 111 110 97 108 102
6a 6f 6e 61 6c 66
0110 1001 0110 1111 0110 1110 0110 0001 0110 1100 0110 0110
    • If you are using a computer at school, you could try looking at the file in the terminal using $ hexdump -C work20.txt

Image encoding

  • Images are often represented as a grid of color values for pixels, where each pixel is given separate values for Red, Green, and Blue (in that order).
  • Here is all the color information for a very small (5x5 pixel) image: 
     FF 00 00 FF 00 00 FF 00 00 FF 00 00 FF 00 00
 00 FF 00 00 FF 00 00 FF 00 00 FF 00 00 FF 00
 00 FF 00 00 FF 00 00 FF 00 00 FF 00 00 FF 00
 00 FF 00 00 FF 00 00 FF 00 00 FF 00 00 FF 00
 FF 00 00 FF 00 00 FF 00 00 FF 00 00 FF 00 00
  • Describe what these numbers represent, as well as what the image looks like.

Emojis!

  • In order to handle more potential characters that ASCII’s measly 128, we have a new standard, Unicode!
  • You can get unicode information for any character here: https://symbl.cc/en/emoji/
    • When you click on an emoji, you can see it’s technical information and encoding. For example:
    • 😀 https://symbl.cc/en/1F600/
      • Name: Grinning Face
      • Unicode number: U+1F600
      • UTF-8 Value in hex: F0 9F 98 80
      • Number of Bytes used to encode: 4B (hint: look at the binary representation, how many bits does it need?).
  • Pick a letter in the english alphabet, and provide the following information:
    • letter
    • Unicode number
    • UTF-8 value
    • Number of bytes used to encode the letter
  • Pick an emoji (keep it clean), and provide the following information:
    • emoji name
    • Unicode number
    • UTF-8 value
    • Number of bytes used to encode the emoji
  • Here is some further information on unicode, it’s a bit technical, but describes how it works in more detail: https://blog.daftcode.pl/unicode-details-for-developers-300dc6f6e11e.