Cs ch1

Different lossy and lossless

Lossy

Remove unnecessary data from file

delete permanently

Lossless

• not lose any data return

• Can return back to original form

Lossy tile compression algorithm

mpact 3

MP4

JPEG

IMAGE- reduce resolution color depth

SOUND - reduce sampling rate and sampling resolution

MPEG - 3

• Reduce the size of a normal music file about 90%

How it does that

Remove sound that human cannot hear ef softer sound

MPEG - 4

Allow storage of multinedia file rather than sound it remove certain pixel in algarithm in video without as noticing

JPEG

used for bitmap image. that it will reduce color shade that not noticing

Lossless algorithm

• RLE( Run length encoding)

• Compression of number different format

• Reduce size of Adjacent, IDENTICALOATA

• repeated string encoded into 2 value

• Eg 999556667

  • 9(3)5(2)6(3)7

Sampling rate

Number of sample per second

Sampling resolution

Number of bit per sample

How computer represent image

Pixel convert to binary

Bitmap

Bitmap made up of pixel

Pixel

Small elements that made up by bitmap

Color depth

No. of bit use to represent each color

Image resolution

Refer to the no. of pixel use to made up an image

Dynamic range

Ratio between brightness and darkness part of image

Character set

Allow computer to store and manipulate text data consistently

Decribe MAC address

Made up 48 bit as a 6 group

NN NN NN - identify number

DD DD DD -serial number

It identify device on the internet