improc ass4: Fixed typo.

improc/ass4/report/report.tex

@@ -135,7 +135,7 @@ G = convolve(F, Gauss(s), mode='nearest')
 \end{verbatim}
 
 The timing results of the first code snippet are displayed in figure
-\ref{fig:times-1d}. The graphs shows that the 1D convolution has a
+\ref{fig:times-1d}. The graph shows that the 1D convolution has a
 computational complexity of $\mathcal{O}(\sigma)$, which is much faster than
 the 2D convolution (certainly for higher scales).
 
@@ -211,4 +211,4 @@ edge detection on the cameraman image using a scale of 2, a lower threshold of
 	\label{fig:canny}
 \end{figure}
 
-\end{document}
+\end{document}
\ No newline at end of file