T6 Worksheet 6 - Compression - Lossy Lossless * (Amalgam)

For each scenario, suggest whether lossy or lossless compression should be used.

A music track

• Lossy

• Lossless

For each scenario, suggest whether lossy or lossless compression should be used.

A text document

• Lossy

• Lossless

For each scenario, suggest whether lossy or lossless compression should be used.

A video clip

• Lossy

• Lossless

For each of the scenario, suggest whether lossy or lossless compression should be used.

A web image

• Lossy

• Lossless

For each scenario, suggest whether lossy or lossless compression should be used.

A software application

• Lossy

• Lossless

For each of the scenario, suggest whether lossy or lossless compression should be used.

A database

• Lossy

• Lossless

What is meant by ‘file compression’?

• Compression means to reduce the size of a data file whilst still retaining most, or even all, of the original information

• Compression means to increase the size of a data file whilst still retaining most, or even all, of the original information

Give three reasons why file compression is useful

• Compressed files require less storage space than uncompressed ones

• Compressed files upload and download faster than uncompressed ones

• Compressed files enable online streaming services to provide a good transfer speed and reduce the risk of buffering

• Analog-to-digital converters often have a file size limit for attachments so compressing a file means that you are less likely to hit that limit

Lossy compression looks for patterns in the data and determines how much can be discarded without noticeably affecting the overall quality of the file.

• True

• False

Lossless compression is an alternative method of compression which enables you to reduce the file size without losing any of the quality.

• True

• False