compression

• label

  A) reducing

  B) size

  C) takes up less space

  D) secondary storage

  E) maximise

  F) amount

  G) store

  H) minimise

  I) transfer time

  J) uploaded

  K) downloaded

  L) streamed

  M) network

  N) lossy

  O) lossless

  
• label

  A) lost

  B) reduce

  C) secondary storage

  D) irreversible

  E) greatly

  F) quality

  G) acceptable

  H) images

  I) video

  J) sound

  K) similar colours

  L) colours

  M) overall

  
• lossy: Data has been removed and the overall quality has been reduced, however it is acceptable as it is difficult to visually see a difference
• label

  A) encoded

  B) reversible

  C) original

  D) dramatically

  E) loss in quality

  F) unacceptable

  G) documents

  H) algorithms

  I) patterns

  J) repetition

  K) PDF

  L) decompression

  M) reverses

  N) more

  O) share

  P) network

  
• label

  A) decrease

  B) quicker

  C) data is lost

  D) noticed

  
• • image - reducing colour depth, reduces range of colours
  • audio - reducing bit depth of samples

  Various lossy standards exist:

  1. JPEG file format
  2. MPEG file format compresses audio and video - more suitable for streaming media
  3. MP3 is a lossy format for audio, including music

  Various lossless standards exist:

  1. PDF allows lossless compression of text documents
  2. GIF is a lossless image file format

  One method of lossless compression is run length encoding (RLE). RLE looks at the data in a file for consecutive runs of the same data. These runs are stored as one item of data, instead of many.