Run-Length Encoding

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 4K image has a resolution of 3840 x 2160 pixels and a color depth of 24 bits per pixel. Calculate the file size of the image in bytes, then convert it to MiB. Express the answer in three digits.

A 4K video has a file size of 8,589,934,592 bits. Convert this file size to gigabytes. Express the answer in one digit. Don’t forget the unit.

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

Name one example of lossless compression.

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 001}

_{Red is 100}

_{Black is 000}

_{White is 111}

_{Hint: do not separate the rows and write your answers without spaces or lines. Example: instead of writing. 4 000, 1 001, 2 100 you must write: 400010012100}

Given that each pixel is represented by 3 bit, what is its uncompressed file size? Include units.

(Write this down, you'll need it later.)

What is the compressed file size of the image? Include units.

(Write this down, you'll need it later.)

BONUS: What is the percentage reduction in file size of the image?

^{Express in 3 significant figures.}