Compression

Compression

by BSN Computing

Multiple Select

In this lesson I am going to learn to ... ?

• Give reasons to compress data

• Describe how compression affects file size

• Identify disadvantages of compressing files

• Explain difference between lossless and lossy compression

• Describe advantages of lossless and lossy compression

Multiple Choice

In Computer Science, what does compression refer to?

• Making a file's storage size smaller

• Making a file unreadable

• Making a second coopy of a file

• Making a machine code version of a source file

Multiple Choice

What is compression applied to?

• Files

• Folders

• Programs

• Data

Multiple Choice

The effect of compression is to make the ______ of a file _______

• size

  smaller

• type

  executable

• size

  larger

• contents

  unreadable

Multiple Select

Choose two reasons for compressing files ...

• To reduce storage requirements

• To reduce network transmission time

• To reduce execution time

• To reduce translation time

Multiple Select

Choose two types of file compression ....

• lossless

• lossy

• lossable

• lossmore

Multiple Choice

Which one of these image file formats uses lossy compression?

• .jpg

• .png

• .bmp

• .gif

Multiple Choice

Which one of these image file formats uses lossless compression?

• .jpg

• .png

• .bmp

Multiple Select

Choose all the advantages of lossless compression ...

• No data is removed

• Original data can be reconstructed

• Achieves higher level of compression

• Can be applied to all types of data

Multiple Select

Choose all the advantages of lossy compression ...

• Data is encoded rather than removed

• Original data can be reconstructed

• Achieves higher level of compression

• Data loss usually not noticeable to human perception

Multiple Select

Choose all the disadvantages of lossy compression ...

• Parts of the original data is removed forever

• Original data can not be reconstructed (decompressed)

• Achieves lower level of compression

• Data loss usually vnoticeable to human perception

Multiple Select

Choose all the disadvantages of lossless compression ...

• Parts of the original data is removed forever

• Original data can not be reconstructed (decompressed)

• Achieves lower levels of compression

• Data loss usually very noticeable to human perception

Multiple Choice

When compressing media files like images, audio and video, there is a trade-off between file _______ and compression __________ chosen.

• size

  algorithm

• type

  method

• format

  ratio

Multiple Select

In this lesson I have learned to ...

• Describe how compression affects file size

• Give reasons for reducing file sizes

• Explain difference between lossless and lossy compression

• Explain advantages/disadvantages of both

• Identify problems with compression

Open Ended

Thinking Hard

Now that you have finished this lesson, what questions do you still have on this topic?

(press Shift+Enter to take a new line ...)

Poll

How much of this lesson have you understood?

• None of it

• Some of it

• Most of it

• All of it