Can anyone help me with this?

I have a JPanel with a corresponding BufferedImage of the same size
(w,h)

I also have a two dimensional float array representing an image that
I've realised using a BufferedImage of a different (and larger) size
(w',h'), with a custom IndexColorModel and a DataBuffer of type float
(which constitutes the raster).

How do I blit the larger image to the JPanel buffer (which will be
viewed on the screen). Graphics/Graphics2D.drawImage seems to use only
the default colormodels. I seem to be missing something in terms of
how to use drawImage correctly, or perhaps there's another way to do
this.

Essentially, I wish to draw the float array to the JPanel buffer, so
that when I change the float values, the buffer gets updated
automatically and I see the results on the screen by invoking the
paint method of the JPanel (as a changing image). Any help would be
greatly appreciated!

Abhi