Options/modifiers for the Movie Cube Tool

This is a work in progress with more options and perhaps a
different style latter.

There are 4 options that can be applied while making a movie
which can be set with the check boxes in the upper half of
this widget. The filter option uses whatever filter is set in
the "filters" widget (under single window tools) and applies it
to each image. Only one filter can be applied. An obvious extension
in the future will be multiple filters. The clock option presently
only works for TRACE data and causes a little clock to appear in the
upper left hand corner of a movie. For TRACAE data, you don't
actually have to remember to set this before movie creation. You
can even set/unset it while a movie is playing. The next two
options are mutually exclusive. They are a running difference movie
and a difference movie made with a specified frame as a reference.
In the former, each frame is subtracted from the previous frame for
the movie. This will be a signed value and the movie will have one
less frame than the number of images in the series. For the other,
each frame is subtracted from the reference. The frame with the
reference will be all zeroes in the movie and it will have the same
number of frames as images in the series. Note that the scaling needs
to be adjusted for these difference images. Fixed scaling is usually
best with a negative value for the minimum.

Both a filter and one of the difference options can be used together.

The lower part of the widget selects the product type. The default
is a ready to view scaled cube. The other choice is the generation
of a 3-D FITS file containing the data. This is used when you just
want to grab the data in the selected image list and put it somewhere
for further processing offline. This FITS file will be corrected for
exposure time differences if the "TRACE exp. comp" checkbox is on
in the "Extract Movie Cube" widget. Otherwise the data will be put in
the FITS file as it was read. Beware, the default has the exposure
compensation option on since this is the usual choice for a read to
view movie.