<Verb>ReadImageAsPureCubicalComplex(str,t):: String, Int --> PureCubicalComplex</Verb><P/>


<P/>
Reads an image file identified by a string str such as
"file.bmp", "file.eps", "file.jpg", "path/file.png" etc.,  
together with an integer <M>t</M> between <M>0</M> and <M>765</M>.
It returns a <M>2</M>-dimensional pure cubical complex corresponding to a  
 black/white version of the image determined by the threshold <M>t</M>. 
The <M>2</M>-cells of the pure cubical complex 
correspond to pixels with RGB value <M>R+G+B \le t</M>.

