untitled

What are the key reasons for compressing data?

• Less space needed for storage

• Less time to transmit

• Higher quality files

• Reduced amount of processing power

• Limited RAM

Lossless compression...

• Is used when not all the information is needed

• Is not as effective as lossy compression

• Can fully regenerate the original file

• Includes files such as .ZIP

• Would be a sensible choice for a music download site

Lossy compression...

• Permanently removes data from a file

• Always leads to a noticeable loss of quality

• Aims to remove redundant data

• Can return the original file to its original quality

• Would be a sensible choice for a music download site.`

Dictionary based compression...

• Is a lossless compression format

• Creates a dictionary of common letter combinations to encode words with fewer characters

• Creates a dictionary of smaller letters so less space is used

• Sends the dictionary with the data

• Doesn't need to send the dictionary with the data

Run-length encoding...

• is Lossless

• is Lossy

• Can only be used for text

• Records the number of repeats of an individual element

• Can be used for a wide variety of file types

Which method of compression does not sacrifice any quality?

• Both methods sacrifice quality

• Neither method sacrifices quality

• Lossless compression

• Lossy compression

Answer explanation

Lossless compression does not sacrifice any quality as it retains all the original data without any loss during the compression process.

How does lossy compression affect multimedia files?

• It has no effect on the file size or quality

• It slightly reduces their quality but significantly reduces file size

• It improves their quality

• It makes them larger

Answer explanation

Lossy compression slightly reduces the quality of multimedia files but significantly reduces the file size, making it the correct choice.

What is a key advantage of lossless compression?

• It is faster than lossy compression

• It maintains the original quality of the file

• It is only used for text files

• It reduces file size more than lossy compression

Which type of files is most commonly compressed using lossy methods?

• Spreadsheet files

• Image and audio files

• Text files

• Executable files

Why might someone choose lossy compression over lossless compression?

• To increase the quality of the file

• To significantly reduce the file size

• To ensure no data is lost

• To make the file compatible with more devices