2.6 Compression Flashcards
What is compression?
Algorithms which reduce file sizes
What is decompression?
The process where compressed data is returned to its original format
What sort of media is used with compression?
Sound, image and video files
What are the 2 different types of compression?
Lossy and Lossless
Lossy compression
Permanently loses some data
Give some lossy compression artefacts
- Small mistakes (digital artefacts)
- Noise
- Blocks
Does lossless image compression lose any of the image data?
No
What does the losseless image compression algorithm do?
Finds groups of repeating data and records data once along with the number of repetitions
Compression advantages
- Download times are reduced
- Data allowances go further
- Possible to transmit video and music data streams as fast as they are playing
Benefits compression
- Faster transmission time
- Reduces download times of video, sound and image files
- Images inside web pages appear faster
- Reduces space on disk/servers
What is buffering?
Delayed video or music streaming.
What can cause buffering?
The download speed is slower than the playback speed
Give some Lossy file formats
- JPEG
- MP4
- MP3
Give some Lossless file formats
- PNG
- ZIP
- GIF
- FLAC
- ALAC
JPEG
Photos
