Zoom in, zoom out

Sometimes you might open up a big image and you simply can't view it in its entirety in Online Image Editor. Luckily there a few possibilities to zoom out (or zoom in). You can use a horizontal zoom scroll bar to zoom in or zoom out immediately. You can also use the scrollwheel on your mouse.
Online Image Editor also has a dropdown box with predefined percentages to zoom. You can also choose to zoom in/out automatically to match the image height or image width (or both).
Last but not least, you can also add to the script that calls Online Image Editor what exact zoom should be perfomed upon loading an image. Online Image Editor will then scale the image accordingly.