File compression

Cards (12)

What is file compression?
The process of reducing the size of something
State 3 advantages of using file compression
Facilitates faster transfer over networks e.g. internet
Allows us to send files as email attachments (Most have size limits)
Helps store media files digitally as they require huge amount of storage when uncompressed
State the two types of file compression: 
Lossy
Lossless
Define 'Lossy compression'
Reduces file sizes by permanently eliminating some data, rending the compression effects irreversible
State the types of file compressions that use lossy compression
Video compression
Image compression
Audio compression
State 2 methods employed in lossy compression
Reducing the number of colours
Reducing the number of images
State a drawback of using lossy compression
Compressed files have lower quality, and their original high quality cannot be restored
Define 'Lossless compression'
Reduces data size without sacrificing any information, allowing the original form to be restored upon decompression
State 2 examples of lossless compression
Encoding repeated characters (Saves storage space and can be reverted to its original form)
How do images utilize lossless compression?
By grouping identical colours
State an advantage of lossless compression
Files can be restored to their original quality as no data is lost
State a drawback of using lossless compression
File sizes are generally larger than those produced through lossy compression