Martin Coath edited section_Methods_The_abbreviation_textsc__.tex  about 8 years ago

Commit id: c23c7ab3f0406e4c0ed654c152c6b4f998ad4e9f

deletions | additions      

       

The simplest form of the algorithm was used for all the results in this paper. For results derived from monochrome images each pixel is defined by three values $i,j,k$ where $i$ and $j$ are the row and column positions of the pixel respectively, and $k$ is the value of the pixel on the greyscale from 0 (black) to 1 (white). Images are processed on a pixel-by-pixel basis and the \textsc{skv} value of each pixels is calculated thus:  \begin{enumerate}  \item assemble the vector  $\vec{k}_{j}$ of values for a horizontal  window of $n$ contiguous  pixels $k_{[i,j; i,j+1; i,j+n-1]}$in the horizontal direction  \item repeat with $\vec{k}_{i}$ of values for a vertical  window of $n$ pixels $k_{[i,j; i+1,j; i+n-1,j]}$vertically  \item both vectors are normalized, so they can be treated as distributions, and the Skewness $\gamma$ of each distribution is calculated, $\gamma_j$ and $\gamma_i$  \item the \textsc{skv} value of the pixel is the larger of the two values $\max(\gamma_j, \gamma_i)$  \end{enumerate}