Image properties affect the file size and the quality of your image. We have to consider the purpose of the image and decide which is most important, file size or image quality.

Image properties are:

RESOLUTION
PIXEL DIMENSION
COLOUR MODE
COLOUR DEPTH

Read the information for each property and use it to answer the questions.

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Image Properties

RESOLUTION aka how many pixels per inch

When making a graphic for print, we need to make sure the image is very high quality. The printer ink dots that make up the image are very fine and therefore the image can be very detailed, so we need a resolution of 300 DPI (dots per inch). Because it is more detailed, the file size will be large!

If you are on a mobile or tablet, you don't have a lot of storage space. Images with a large file size take ages to send. The screen pixels on monitors, tablets and phones are not as small as a print ink dot. It is better to use a smaller resolution. A resolution of 72 PPI (Pixels per inch) is a good balance between quality and file size for screen images.

This refers to how big your picture is, height x width. The bigger the image, the larger the file size.

However, if the image is smaller than the final web or print version, it will get blurry. Therefore, it is important to set the image to the size of the final product.

IMAGE SIZE aka. Pixel dimensions

Colour Mode is where you choose what type of colour mode you will use.
For example:

RGB (red green blue) is chosen for computer monitors and screens.

CMYK (cyan, magenta, yellow and black) used for printed products.

​COLOUR MODE

Colour depth refers to how many colours are in each pixel.

Each pixel is stored on the computer using binary bits.

The more bits you allow the more colours you can have and your image will be represented more accurately. The more colours, the larger your file size.

(Sound familiar? it should do – you covered this on the spreadsheet task with the smiley face)

​COLOUR DEPTH