Compression

Question 1

What are the 2 types of compression?

Answer 1

Lossy

Lossless

Question 2

What are 4 main reasons for compressing a file?

Answer 2

Less storage space required for files
Faster download and uploads
Smaller file attachments for email
Coping with slow links when streaming

Question 3

What is the 1st equation for compression ratio?

Answer 3

Compression Ratio = Original Data Size / Compressed Data Size

Question 4

What is the 2nd equation for compression ratio?

Answer 4

Compression Ratio = Original Data Rate / Compressed Data Rate

Question 5

What is lossy compression?

Answer 5

Permanently eliminating certain information from the file

Question 6

How does the algorithm for lossy compression work?

Answer 6

Depends on patterns being present within the information. The algorithm looks at the data, tries to identify the patterns and decides how much it can throw away without noticeably affecting the quality of the data

Question 7

What are 3 common types of lossy compression for music, images and videos?

Answer 7

Music : MP3 files
Image: JPG files
Video: MP4 files

Question 8

What is lossless compression?

Answer 8

The file is reduced in size, without losing any quality so the original file can be restored

Question 9

What are 4 type of lossless compression files for images, audio and any other kind of file?

Answer 9

Images : PNG
Audio : WAV and FLAC
A very popular lossless compression format for storing any kind of file is .ZIP.

Question 10

What is data streaming compression?

Answer 10

Means to reduce the bit rate of the video or music stream

Question 11

Which type of compression is more effective at decreasing the size of a file?

Answer 11

Lossy Compression, because it has a higher compression ratio