The rectangular area labeled Initial point location relative to frame size lets you pick the initial location of the point parameter when the plug-in is first applied. The location can be entered numerically as well, via the X and Y text fields. Please note that the initial location of a point parameter is ignored by Final Cut Pro 5.1.2 (all later versions of Final Cut Pro respect the values you enter).
The Map coordinates to option lets you control how the point coordinates will be converted when fed to the Quartz composition inputs.
If the coordinates are to be used by a Core Image filter patch (such as a Zoom Blur), choose Pixel-based values.
If the coordinates are to be used by one of the other Quartz Composer patches, choose the Quartz Composer coordinate system.
The Compensate for Frame Margin parameter lets you control the coordinates that will be fed to your composition when the output frame is larger than the input frame. Filters running in Motion and After Effects allow users to add a Frame Margin around the source to make room for any pixels “splilled” by the effect. When this option is enabled, the coordinate will be relative to the original image location. When this option is disabled, coordinates are expressed in relation to the size of the enlarged frame. This option is only available when the Map coordinates to option is set to “Pixel-based values”.