Roberts Filter - Edge Detection & Gradient Image

Roberts

This method calculates a gradient image using the Roberts filter matrix. Large gray value differences between neighbors are shown as light gray values. No changes are indicated by a value of 0 (black). Edges are thinner than with the Sobel method.

Parameter	Description
Normalization	Defines how out-of-range pixel values are mapped. The calculated pixel values of the output image may be out-of-range and are mapped into the available range.
-	Clip	Values exceeding the pixel value range are set to the highest value available (white), values falling short of the pixel value range are set to the lowest value available (black). The effect corresponds to underexposure or overexposure. This means that in some cases information is lost.
-	Automatic	Normalizes the pixel values automatically to the available pixel value range. The highest resulting value is mapped to the maximum pixel value, the lowest resulting value to 0. As a result, the whole range of resulting pixel values is compressed evenly.

Parameter

Description

Normalization

Defines how out-of-range pixel values are mapped.

The calculated pixel values of the output image may be out-of-range and are mapped into the available range.

Clip

Values exceeding the pixel value range are set to the highest value available (white), values falling short of the pixel value range are set to the lowest value available (black). The effect corresponds to underexposure or overexposure. This means that in some cases information is lost.

Automatic

Normalizes the pixel values automatically to the available pixel value range. The highest resulting value is mapped to the maximum pixel value, the lowest resulting value to 0. As a result, the whole range of resulting pixel values is compressed evenly.