On a computer all data is stored as binary 

What is a pixel? 

A small square that makes up a part of an image. 

Resolution 

The number of pixels in width and height. 

To calculate the amount of pictures in an image, multiply the width by height. 

Eg 

6p * 4p = 24p 

 

Low resolution = less pixels 

If you stretch them out they become pixelated. To be able to stretch a picture they need more pixels 

 

PPI and DPI 

Pixels per inch 

Dots per inch 

72PPI for screen 

300PPI for print 

 

Width in pixels 

Height in pixels 

Screen size inches 

 

R = (W * H) / S 

 

Colour Depth/Bit Depth 

Measurement of the amount of possible colours that can be displayed with the amount of bits given 

Greyscale has 256 possible shades 

Each pixel has a number that is made up of binary 

4 bit depth, means you have 4 bits, you can represent 4 colours. 

More bit depth means more colours. 

True colour has 24 bits 

RGB Channels 

Red 

Green 

Blue 

16777216 Total possible colours 

Each pixel is given a binary number to give it a colour 

Metadata 

Data about data 

When it was created 

When it was modified