Color Reduction with border Detection
Color reduction using the Border Detection filter is used when you have detailed images. This filter tries to locate and highlight the edges of the figures that make up the image. The figures shall have sufficient contrast and shall not be too small.
Unlike the Pencil Drawing filter, this filter analyzes the contrast of colors according to the chosen directions. In some cases the edges are detected more accurately than the other filters, because you can choose the directions in which you want to analyze the image.
This filter has some parameters:
- Contrast: Contrast value between adjacent colors to identify edges to highlight. Low contrast detects the subtlest variations, while high contrast detects the most pronounced variations;
- Border Above: if this box is checked, the image is also analysed from above;
- Border Below: if this box is activated, the image is also analyzed from below;
- Left border: if this box is activated, the image is also analysed from the left;
- Right edge: if this box is activated, the image is also analysed from the right.
The directions in which the image can be analyzed can be freely activated or deactivated. If you deactivate all of them, the filter will not detect any edges, so you must leave at least one activated.