Kompresja danych... accept the convention that the word "compression" be encoded as "comp".... ZIP file format... both the sender and receiver of the information.

Kompresja danych

... accept the convention that the word "compression" be encoded as "comp".

... ZIP file format

... both the sender and receiver of the information understand the encoding scheme

... Lossless vs. lossy compression

Kompresja danychstratna

Claude E. Shannon, 1948

A Mathematical Theory of Communication

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1. ocroh hli rgwr nmielwis eu ll nbnesebya th eei alhenhttpa oobttva nah

2. on ie antsoutinys are t inctore st be s deamy achin d ilonasive tucoowe

3. in no ist lat whey cratict froure birs grocid pondenome of demonstures

4. ...

Kompresja danych bezstratna

MP3 digital audio encoding and lossy compression format, 1991, ISO

... psychoacoustic models

... tradeoffs between data size and sound quality

... bit rate 128 - 320 kbit /s

... compression artifacts ... sound of applause: it is hard to compress because of its randomness and sharp attacks

CD parameters: 44.1 kHz, 2 channels, 16 bits per channel -> 1411.2 kbit/s

JPG Joint Photographic Experts Group

1994, ISO 10918-1

method of compression for photographic images

lossy compression

... from RGB into a different color space called YCbCr

... discrete cosine transform

MPEG Moving Picture Experts Group

kompresja 0plik 16,2KB

kompresja 20plik 9,94KB

kompresja 50plik 9,29KB

kompresja 100plik 8,37KB

JPG

Szum

bmp: 24bit - 29,3 KB 256kolor – 10,8 KB 16kolor – 5,19 KB

JPG kompresja 20

JPG kompresja 100

GIF Graphics Interchange Format

... limited to a palette of 256 colours or less

... Unisys ... owned some patents to key parts of the GIF compression technology, and has started demanding fees from every company whose software uses the (freely available) GIF code

bmp 24bit - 29,3 KB gif – 14,0 KB bmp 256kolor – 10,8 KB