Load a PS image for display on FRAME.
SPEC is an image specification, IMG-HEIGHT and IMG-WIDTH are width
and height of the image in pixels. WINDOW-AND-PIXMAP-ID is a string of
the form "WINDOW-ID PIXMAP-ID". Value is non-nil if successful.
(fn FRAME SPEC IMG-WIDTH IMG-HEIGHT WINDOW-AND-PIXMAP-ID PIXEL-COLORS)