9.8. Erodir

9.8.1. Visão-geral

Figura 17.188. Applying example for the Erode filter

Applying example for the Erode filter

Imagem original

Applying example for the Erode filter

Filter Erode applied

Este filtro amplia e realça as áreas escuras de uma camada ativa ou seleção.

For every image pixel, it brings the pixel Value (luminosity) into line with the lowest Value (the darkest) of the 8 neighboring pixels (3×3 matrix). So, a dark pixel is added around dark areas. An isolated pixel on a brighter background will be changed to a big pixel, composed of 9 pixels, and that will create some noise in the image.

In this image, the studied pixel has a red border and the studied 3×3 matrix has a green border. Thus when the pixel marked with I is inside the green border, the studied pixel turns to black.

A larger dark area will expand by one pixel in all directions:

O filtro foi aplicado 3 vezes.

On more complex images, dark areas are widened and enhanced the same, and somewhat pixelated. Here, the filter was applied 3 times:

Obviamente, se o fundo for mais escuro que a imagem da frente, então a imagem inteira será coberta.

9.8.2. Activating the Filter

This filter is found in the main menu under FiltersGenericErode.

9.8.3. Exemplos

Figura 17.189. Erode text

Erode text