Specifies GUI Magnify Window control options.

Values:

IG_GUI_MAGNIFY_POPUP_WIDTH	Specified attribute is a width of Popup Magnify window.
IG_GUI_MAGNIFY_POPUP_HEIGHT	Specified attribute is a height of Popup Magnify window.
IG_GUI_MAGNIFY_POPUP_ZOOM	Specified attribute is a zoom factor of Popup Magnify window.
IG_GUI_MAGNIFY_POPUP_CIRCLE	Specified attribute indicates whether the Popup Magnify window is circle (TRUE) or rectangular (FALSE).
IG_GUI_MAGNIFY_POPUP_GRPID	Specified attribute is a group ID of Popup Magnify window.
IG_GUI_MAGNIFY_POPUP_CURSOR	Specified attribute is a cursor of Popup Magnify window.
IG_GUI_MAGNIFY_XPOS	Specified attribute is a current X position on source image.
IG_GUI_MAGNIFY_YPOS	Specified attribute is a current y position on source image.