+75% or more of each image will always be visible. If set to 100%,
+then the images will always fill the screen, and no panning or
+zooming will occur. (Images will still smoothly fade from one
+to another if \fI\-fade\fP is non-zero.)
+.TP 8
+.B \-titles
+Whether to print the file name of the current image in the upper left corner.
+.TP 8
+.B \-letterbox
+In "letterbox" mode, when an image is not the same aspect ratio as the screen,
+black bars will appear at the top/bottom or left/right so that the whole
+image can be displayed. This is the default.
+.TP 8
+.B \-clip
+In "clip" mode, when an image is not the same aspect ratio as the screen,
+we will zoom in further until the image takes up the whole screen.
+This is the opposite of \fI\-letterbox\fP.
+.TP 8
+.B \-delay \fInumber\fP
+Per-frame delay, in microseconds. Default: 20000 (0.02 seconds.).
+.TP 8
+.B \-fps
+Display the current frame rate, CPU load, and polygon count.
+.TP 8
+.B \-cutoff \fInumber\fP
+If the frame rate we are achieving is lower than this, then panning,
+fading, and zooming will be disabled. Default 5 FPS.
+
+The idea here is that if your machine can't maintain a decent frame
+rate, then it must not have fast 3D hardware, so we might as well
+behave in a simpler manner. Set this to 0 to disable this check.
+.TP 8
+.B \-debug
+Prints debugging info to stderr.