The RDPIX procedure interactively displays the X position, Y position, and pixel value at the cursor.
This routine is written in the IDL language. Its source code can be found in the file
subdirectory of the IDL distribution.
RDPIX displays a stream of X, Y, and pixel values when the mouse cursor is moved over a graphics window. Press the left or center mouse button to create a new line of output. Press the right mouse button to exit the procedure.