In OSX 10.3 and above. Ctrl Click the image you wish to resize, move your mouse cursor over Open With. Locate and Click on ColorSync Utility.app from the Open With list.
If ColorSync Utility.app is not on the Open With menu then go to the bottom of the Open With menu and Click on Other…. The Choose Application window will appear. Select the Applications folder from the left of the window, then scroll down to Utilities in the Applications folder, ColorSync Utility.app can be found here. Click on ColourSync Utility and then Click on Open.
At the top left of the ColorSync Utility application there are five icons: Zoom In, Zoom Out, Image Info, Adjust image size & Image correction.
To use the Adjust image size function, Click on the 4th button in from the left.
You should now see a dialog with the following: Current Size, Resize, Quality and Set DPI.
Select Width from the drop down menu next to Resize: and in the field next to to: enter 1280.
Now click on Apply, go to the File menu and click on Save As, Save the image somewhere convenient and repeat the process with any other images you need to resize. When complete return to your Account Dashboard on ownersapartments.co.uk.