This is caused because 100% zoom is set to the RadImageEditor. If you desire to fit the image in RadImageEditor's viewport, you should set the ScaleFactor property to 0. In this way image' scaling is set to 'AutoFit'.
If this is not the case and you desire to hide the settings container at right, you can attach to the RadImageEditor's CommandExecuted event and to hide the container in the event handler when a CropTool is selected:
sender, ImageCommandExecutedEventArgs e)
I hope this helps.
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