xmag - magnify parts of the screen
xmag [ -mag magfactor ] [ -source geom ] [
  -toolkitoption ... ]
The xmag program allows you to magnify portions of an X screen. If no
  explicit region is specified, a square with the pointer in the upper left
  corner is displayed indicating the area to be enlarged. The area can be
  dragged out to the desired size by pressing Button 2. Once a region has been
  selected, a window is popped up showing a blown up version of the region in
  which each pixel in the source image is represented by a small square of the
  same color. Pressing Button1 in the enlargement window shows the position and
  RGB value of the pixel under the pointer until the button is released. Typing
  ``Q'' or ``^C'' in the enlargement window exits the program. The application
  has 5 buttons across its top. Close deletes this particular
  magnification instance. Replace brings up the rubber band selector
  again to select another region for this magnification instance. New
  brings up the rubber band selector to create a new magnification instance.
  Select puts the magnification image into the primary selection.
  Paste copies the primary selection buffer into xmag. Note that
  you can cut and paste between xmag and the bitmap program.
  Resizing xmag resizes the magnification area. xmag preserves the
  colormap, visual, and window depth of the source.
xmag uses the X Toolkit and the Athena Widget Set. The magnified image is
  displayed in the Scale widget. For more information, see the Athena Widget Set
  documentation. Below is the widget structure of the xmag application.
  Indentation indicates hierarchical structure. The widget class name is given
  first, followed by the widget instance name.
	Xmag xmag
		RootWindow root
		TopLevelShell xmag
			Paned pane1
				Paned pane2
					Command close
					Command replace
					Command new
					Command select
					Command paste
					Label xmag label
				Paned pane2
					Scale scale
		OverrideShell pixShell
			Label pixLabel
  - -source geom
- This option specifies the size and/or location of the source region on the
      screen. By default, a 64x64 square is provided for the user to select an
      area of the screen.
- -mag integer
- This option indicates the magnification to be used. 5 is the default.
Dave Sternlicht and Davor Matic, MIT X Consortium.