Images can be uploaded to Global Crossroads for Image Resources, Data Resources, or Dispatches. It is important that images are properly sized, so that they will display well on the Global Forum media wall and the Global Crossroads web app. Mac computers have a handy feature in the Preview application that allows you to resize quickly.
If you do not want to use the Preview application, click Tools menu >> Adjust Size. You will see an interface like the one below. Click into the Fit into menu and select the 1920 x 1080 option. And make sure the resolution is 72 pixels/inch. This will resize your image properly, without altering dimensions. Images do not have to be cropped to a specific shape. PC users will need to choose an appropriate image processing software to make similar changes.