T4 Homework 4 - Images - J277

1 - (a) Describe how a black and white image could be represented in binary

• The image is created as a series of pixels, each of which can be represented by a binary digit, 1 for white and 0 for black or vice versa.

  Metadata stored with the file specifies dimensions of image in pixels / resolution / number of colours so the image can be recreated from the data bytes making up the file.

• The image is created as a series of nodes, each of which can be represented by a binary digit, 1 for white and 0 for black or vice versa.

  Beta-data stored with the file specifies dimensions of image in pixels / resolution / number of colours so the image can be recreated from the data bytes making up the file.

1 (b) How many bits per pixel would be required for an image with a palette of 256 possible colours?

2 - State two factors that affect the file size of a bitmap image.

• Colour depth / number of bits per pixel / number of colours in the image

• Storage media

• The OS

• Dimensions of the image in pixels / resolution

3 - Calculate the file size of each of the following images.

a. A 256 colour icon with dimensions of 50 x 50 pixels

See the image example for help

Hint to start you off

50 x 50 pixels = 2 500, x 8 bit =

What is the answer in bytes?

3 - Calculate the file size of each of the following images.

b. A 16 colour icon with dimensions of 100 x 100 pixels

See the image example for help

What is the answer in bytes?

4 - Additional metadata data is stored alongside the binary colour values for each pixel.

Give two examples of metadata.

• File name

• Flux

• File type

• Capacitor