Properties And Formats Of Media Files

Question 1

What is Compression

Answer 1

Compression is taking something big and making it smaller.

Question 2

What does compression allow you to do across a network and why?

Answer 2

Faster transmission
(Smaller files take less time to transmit)

Question 3

Why are files commonly compressed?

Answer 3

To save storage

Question 4

What is lossy compression?

Answer 4

File sizes are reduced by permanently deleting some data from the file.

Question 5

What is a disadvantage of lossy compression?

Answer 5

Data cannot be restored and so the effects of the compression cannot be undone. Compressed to lower quality.

Question 6

Where is lossy compression commonly used?

Answer 6

Video, audio and image compression
E.g JPG

Question 7

What is an advantage of lossy compression

Answer 7

File sizes are reduced much more using lossy compression than lossless

Question 8

What is lossless compression?

Answer 8

The computer packs the data into less space.

Question 9

What is an advantage of lossless compression

Answer 9

No data loss
Can be decompressed back to its original form.

Question 10

What commonly uses lossless compression?

Answer 10

Image, video and audio formats
PNG
ZIP

Question 11

What is a disadvantage of lossless compression?

Answer 11

File sizes are generally larger than those compressed with lossy compression

Question 12

What are Bitmap images (Raster images)?

Answer 12

Made up of many individual pixels formed into a grid to create the image

Question 13

What are Vector images?

Answer 13

The co-ordinates of point on a page and connected with straight and curved paths that are calculated mathematically

Question 14

What is an advantage of a raster image?

Answer 14

Can store complex colours

Question 15

What is a disadvantage of raster images?

Answer 15

When you take a raster image and resize it to be bigger, it will start to look pixelated.

Question 16

What is an advantage of vector images?

Answer 16

You can resize your image without losing quality

Question 17

What is a disadvantage of vector images?

Answer 17

Can only use flat colours or simple gradients

Question 18

What are the two different ways to look at ‘the number of pixels’?

Answer 18

• Pixel dimensions
• Dots per inch (pixels per inch

Question 19

Examples of common pixel dimensions?

Answer 19

-1920x1080
-320x480
-250x250
+1080x1080

Question 20

What does Dots per inch (DPI)/Pixels per inch (PPI) measure?

Answer 20

How many pixels of colour are used per inch of thd image

Question 21

What is DPI resolution commonly used for and the standard resolution?

Answer 21

-Images for printing
- 300 DPI

Question 22

What is PPI resolution commonly used for and the standard resolution?

Answer 22

• Computer displays
• 72 PPI

Question 23

What is TIFF and how is it used?

Answer 23

Lossless compressed raster file format that is commonly used for high-quality printing and scanning

Question 24

What is a disadvantage of TIFF?

Answer 24

doesn’t compress as effectively as other formats, which results in large file sizes
Most web browsers can’t use it

Question 25

What is JPG and how is it used?

Answer 25

lossy compressed raster file format commonly used for online photography and artwork as well as low-quality printing

Question 26

What is an advantage of JPG?

Answer 26

Useful for displaying images on websites

Question 27

What is a disadvantage of JPG?

Answer 27

Reduces quality of the image creating artefacts a d pixelation

Question 28

What is GIF and how is it used?

Answer 28

Lossless compressed raster file format commonly used for simple web graphics and embedding animations in web pages.

Question 29

What is colour depth?

Answer 29

Defines how many colours can be used.

Question 30

What is a disadvantage of GIF?

Answer 30

Low colour depth Not good for things like photographs

Question 31

What is PNG and how is it used?

Answer 31

lossless compressed raster file format commonly used for high-quality images that require transparency