WorksheetsData Representation: Quiz 2
Total questions: 10
Worksheet time: 28mins
What is compression?
deleting unnecessary sounds from a file
reducing file size by removing redundant pieces of data
run length encoding
shrinking an image
A 1080p image (1920 x 1080 pixels) has a colour depth of 16.
How many of these images can fit on a 2GiB pen drive?
(a)
A song is recorded to digital at 60Hz with a bit depth of 12.
The audio is recorded in stereo, and the song is 2 minutes long.
What is the file size of the song?
Express your answer in KiB.
(a)
What is a characteristic of lossless compression?
Quality is sacrificed
The original file can be reconstructed
Compressed files are considerably smaller
Data is eliminated
Name one example of lossy compression
(a)
Name one example of lossless compression.
(a)
The 6x6 pixel image shown is represented in colour, and is compressed by RLE.
What is its RLE code?
(Write this down, you'll need it later.)
Blue is 0 0 255
Red is 255 0 0
(a)
Given that each pixel is represented by 3 bytes, what is its uncompressed file size? Include units.
(Write this down, you'll need it later.)
(a)
What is the compressed file size of the image? Include units.
(Write this down, you'll need it later.)
(a)
What is the percentage reduction in file size of the image?
Express in 3 significant figures.
(a)
