Editor: Drag the Overlay application icon to your Applications folder. If you want Overlay to appear in your Dock, drag it from your applications folder onto your Dock.
Open an image
Drag an image file onto Overlay, or onto Overlay's Dock icon, or choose File > Open from the menus, or click the "Open..." button in the Overlay Control Panel. Overlay can open almost all types of image file, including RAW files from all the Cameras supported by Mac OS X, and it can open PDFs.
Rotate, scale and position it.
The Overlay window can be resized and positioned like any normal window, and the controls in The Overlay Control panel (which can also be repositioned) enables you to scale (resize), rotate and position your image within the window. You can also control the opacity of the main window, and show or hide it as required. The Overlay windows continue to float over ALL other windows on your Mac unless you hide the main window, reduce its opacity to zero, or Quit.
On-image controls
You can also reposition the overlay image by holding down the SPACEBAR while you mouse over the overlay Image Window (like in Adobe Photoshop). To control opacity in the main window hold SHIFT while MouSing. To rotate the image in the main window hold down COMMAND(APPLE) while mousing, and to scale (resize) the image in the main window, hold ALT while mousing. The image can also be positioned using the arrow keys.
Switch on and off, or replace the image
You can switch the Overlay image on and off by using the Show/Hide button (you can also reduce the transparency to zero or InCrease to 100% using the Opacity slider, to Get the same effect). To replace the image in the Overlay window, just open a new file.
Overlay behaves slightly differently to other Apple applications because its windows are ALWAYS visible (otherwise they would not be much use).
