Error in imadjust? and image package?

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Hi I am trying to use some function in octave-forge package, particularly "image-1.0.15". I can't seem to get the result I expected. Can some help to advise?

%%beginning of code%%

This is my script:
f=imread('einstein.tif');
imshow(f)
g=imadjust(f,[0;1],[1;0]);
imshow(g);

%% end of code%%

The link to the image is: http://scien.stanford.edu/images/labsite/einstein.tif

I got all black result. I would expect the image to be inverted. 

I am using Ubuntu 12.04, and install Octave 3.6.1 with image-1.0.15.

Thanks in advance.

Regards,
Oka