Color Reduction with Isolation

Color reduction using figure isolation filters is used to identify figures in an image based on color, brightness, or saturation. Generally these filters are useful when there are dominant figures in a scene. They try to identify and highlight the edges of the figures in an image according to their dominant color, brightness, or sufficient saturation, components that are properly contrasted from the rest.

There are three isolation filters:

- Isolate Color: analyzes the colors of the image and highlights the figure of the chosen color.

- Isolate brightness: analyzes the colors of the image and highlights the figure in which the brightness corresponds to the chosen value.

- Isolate Saturation: analyzes the colors of the image and isolates the figure with the chosen saturation value.

Unlike the Pencil, Marker, and Edges filters, the Isolation filters blank out the rest of the scene and highlight the edges according to the image's source values.

These filters have some parameters:

- Value: the value referring to the chosen filter. For the Color Isolation filter it corresponds to the HLS (Hue Luminance Saturation) color component, while for the Brightness Isolation and Saturation Isolation filters it refers to the brightness and saturation components of the image, respectively.

- Contrast: value of contrast between colors, brightness or saturation of the points under analysis, in order to identify the points to keep or cancel. A low contrast keeps more parts of the image, a high contrast reduces the image only to the sufficiently contrasted parts.