Image editing -Optimising photos

Optimising a photograph means editing it to suit your purpose. Things you might do to optimise a photograph include resizing it, cropping it, increasing the brightness or contrast, or perhaps changing the colours in the photograph.
There are many different types of software for editing photographs.

The most common professional editing software is called Adobe Photoshop. There are however, other free types of image editing software such as Gimp which have similar features to Photoshop.


When you take a photo on your digital camera, you can choose what size it is using the image size button and adjusting the megapixels. However, you may want to resize your image after you have downloaded it onto your computer. 
Here are some reasons why you may need to resize photos:

  • If you have a lot of photos with a very large image size, they may take up a lot of memory space on your computer’s hard drive.

  • To place photographs in a web site you will need to reduce the size of a photograph so that it is easy for others to download.                                                               
  • Sending photos as attachments in an email usually have to be less than 1MB.

  • If you have many photos in a slideshow or movie you may also need to resize them.

Another word for making a photograph smaller is to compress it.

There are many online resize applications you can use for free. Check this one out and have a go resizing one of your images.

Brightness and contrast

picBrightness is the amount of light in a photograph. Contrast is the difference between light and dark areas in a photograph.

Increasing brightness and contrast between light and dark colours can add a clearer look to a photograph.

Cropping reduces the size of the image by cutting out and discarding part of the image. Cropping allows you to focus on the part of the photo that is central to your theme.

Images on this page are from and copyright is covered by the Creative Commons licence. For more details read about CC here.


How to install Gimp on your computer

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Free online resize application

Download GIMP image editing software for free


GIMP Basics (You tube) Part 1
GIMP basics (You Tube) Part 2
How to resize using GIMP
How to crop in GIMP

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