AQA Computer Science GCSE: Compression & RLE

Which type of compression ensures that all of the data is kept?

• Lossless

• Lossy

Lossy compression removes data that isn't needed...

• True

• False

Compression makes file sizes...

• Bigger

• Smaller

• Keeps them the same

An advantage of lossless compression is...

• All data is lost

• The file size stays the same

• All of the important data is kept

A disadvantage of lossless compression is...

• There is a big reduction in file size

• There is only a slight reduction in file size

• There is no reduction in quality

• Cannot be used on text or software files

RLE is a type of compression

• True

• False

The first line of this image in RLE would be...

• 8W, 1Bl, 20B, 1W

• 10B, 4Y, 17R, 2G

• 2G, 10P, 17Y, 2Bl

The correct encoding of the letter C in this tree is...

• 11

• 10

• 01

• 00

Huffman trees use the _______________ of each character to work out their encoding.

• Frequency

• Order in ASCII

• Number value

Which two of the following are appropriate for compressing sound files?

• Lossy

• Huffman Tree

• Lossless

• RLE