| Feature | Descriptor |
|---|---|
| Number of black pixels in the column: | \(c_{1}(x)=\displaystyle\sum_{y=1}^{H}S(x,y)\) |
| Center of gravity of the column: | \(c_{2}(x)={1/H}*\displaystyle\sum_{y=1}^{H}y*S(x,y)\) |
| Second order moment of the column: | \(c_{3}(x)=1/{H^{2}}*\displaystyle\sum_{y=1}^{H}{y^{2}}*S(x,y)\) |
| Position of the upper contour in the column: | \(c_{4}(x)=min\{y|S(x,y)=black\}\) |
| Position of the lower contour in the column: | \(c_{5}(x)=max\{y|S(x,y)=black\}\) |
| Orientation of the upper contour in the column: | \(c_{6}(x)={c_{4}(x+1)-c_{4}(x-1)}/2\) |
| Orientation of the lower contour in the column: | \(c_{7}(x)={c_{5}(x+1)-c_{5}(x-1)}/2\) |
| Number of black-while transitions in the column: | \(c_{8}(x)=NT_{negro->blanco}S(x,y);1\leq y\leq H\) |
| Number of black pixels between the upper and lower contours: | \(c_{9}(x)=\displaystyle\sum_{c_{4}(x)<y<c_{5}(x)}^{H}S(x,y)\) |