Images

Question 1

What are the 2 most popular types of input devices for creating an image in binary form?

Answer 1

Flatbed scanner

Digital camera

Question 2

How does a digital camera work?

Answer 2

It has an image sensor that creates binary files directly.

These files are then stored in the camera’s memory card or transferred by USB cable and Wi-Fi into a computer

Question 3

What are pixels?

Answer 3

One of the individual units (often called dots) that make up an image

Question 4

What does increasing the number of pixels do?

Answer 4

Makes the image looks completely smooth (higher resolution)

Question 5

How does a bitmap image file represent an image?

Answer 5

As a series of pixels

Question 6

What is a popular bitmap image file format?

Answer 6

BMP (Device Independent Bitmap File)

Question 7

Why can BMP files be large and take up a lot of storage?

Answer 7

It has data on every single pixel

Question 8

What word can be used to describe a BMP file?

Answer 8

Uncompressed, as it has data on every single pixel

Question 9

How are JPEG files compressed?

Answer 9

Lossy Compression - Some non-vital pixel information is discarded. So although some quality is lost

Question 10

What is a megapixel equal to?

Answer 10

A unit of resolution equal to one million pixels

Question 11

What can a binary number represent?

Answer 11

A single, specific colour

Question 12

What do you need to display greater range of colours?

Answer 12

A greater range of binary numbers

Question 13

How many colours will 2 binary numbers represent?

Answer 13

2 - black and white

Question 14

What is a greyscale image?

Answer 14

An image containing only different shades of grey

Question 15

What three colours can the cells in our eye pick up?

Answer 15

Red
Green
Blue

Question 16

How much memory is assigned to each pixel?

Answer 16

1 byte of memory for each of those three values (RGB)

Question 17

How many different shades of red could be displayed with a 1 byte pixel?

Answer 17

256

Question 18

How many possible colours could be displayed with a 3 byte number system?

Answer 18

256x256x256 = 16.8 million

Question 19

What is colour depth?

Answer 19

The number of bits per pixel used to represent a colour

Question 20

What does a greater colour depth mean?

Answer 20

The better the colour rendering

Question 21

What happens to the file size with a greater colour depth?

Answer 21

A larger file size because it is storing more bits per pixel

Question 22

What is colour depth measured in?

Answer 22

Bits per pixel

Question 23

What is image resolution?

Answer 23

The number of pixels per inch

Question 24

What does a higher number of pixels cause?

Answer 24

A greater resolution

Question 25

What is resolution measured in?

Answer 25

Dots per inch (dpi)

Question 26

What does a high resolution mean for an image?

Answer 26

A greater amount of detail can be seen

Question 27

What happens to the file size with a greater resolution?

Answer 27

The file size gets larger because more information needs to be stored about the image

Question 28

What is metadata?

Answer 28

Extra information stored in the image file to help render it properly

Question 29

What are digital images stored as?

Answer 29

Data files

Question 30

What 6 things does metadata include?

Answer 30

``` Width in pixels Height in pixels Horizontal resolution in dpi Vertical resolution in dpi Colour (bit) depth Dimensions ```

Question 31

What does metadata help an application to do?

Answer 31

Render an image properly