Lucas Fidon edited subsection_Approximation_of_probability_distribution__.tex  almost 8 years ago

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Hence the following definition of the probability of $(x,y)$ given $T$:  \[P((x,y),T) = \sum_{(x',y')\in T}K((x,y),(x',y'))\]  where $K$ is a gaussian kernel. in practice we take a discrete gaussian kernel filter for $K$.  \begin{table}   \begin{tabular}{ c | c | c } \[ K = \left| \begin{array}{ccc}  0.0625 & 0.125 & 0.0625 \\ 0.125 & 0.25 & 0.125 \\ 0.0625 & 0.125 & 0.0625 \\   \end{tabular}   \end{table} \end{array} \right|.\]  Whereas the simple histogram method places a spike function (i.e. $K = \delta$) at the bin corresponding to $(x,y)$ and update only a single bin, Parzen windowing places a kernel at the bin of $(x,y)$ and updates all bins falling under the kernel with the corresponding kernel value.  As a result using a gaussian filter, the estimated distributions are more smooth and less sparse.