Crash Course Computer Science #21 - Compression

How do files get squeezed into a smaller size?

• reduction

• compression

• shrinking

• constrict

What number represents full intensity for colors in a pixel?

(a)  

One way to compress data is to reduce repeated or redundant information. The most straightforward way is called...

• run-length encoding

• repeated-line encoding

• reverse-logic encoding

• retroactive-line encoding

After compression, how many bytes is our PacMan image?

(a)  

A compression ​ (a)   that has this characteristic is called ​ (b)   compression, because we don't lose anything. The ​ (c)   data is identical to the original before compression, bit for bit.

• technique
• lossless
• decompressed
• style
• lineless
• compressed

What's the most common color block in our example?

• white-yellow

• black-yellow

• yellow-yellow

• white-white

How does the Huffman tree organize data?

• lower frequencies at the bottom

• lower frequencies at the top

What is the Huffman code for white-white?

(a)  

Using the Huffman tree to compress Pac Man, we used only __ - significantly less than the original 48 bytes!

• 14 bits

• 14 bytes

• 24 bits

• 24 bytes

Both ​ (a)   encoding and ​ (b)   coders are ​ (c)   compression techniques. No information is lost; when you ​ (d)   , you get the original file.

• run-length
• dictionary
• lossless
• decompress