**Block Category:** Detection

**Input Image Requirements:** None

**Description:** The Sobel Edge block detects the edges
of an image in both the horizontal and vertical directions with the detected
edges bright on a dark background. The Sobel operator is a discrete
differentiation operator. It combines Gaussian smoothing and differentiation,
and computes an approximation of the gradient of the image intensity function.

**Delta: **Specifies a value used to vary the pixel
intensity. The delta value is added to the results prior to storing them in the
output.** **

**Derivative:** Indicates the direction of edges to be
detected. There are three supported combinations:

Horizontal derivative |
Vertical derivative |
Result |

1 |
0 |
Horizontal edges ( |

0 |
1 |
Vertical edges ( |

1 |
1 |
Calculates an approximation of the gradient
( |

Horizontal: Indicates an integer variable representing the
*x*-derivative.

Vertical: Indicates an integer variable reprenting the
*y*-derivative.

**Kernel Size:** Specifies a value used to extend the
Sobel kernel. The value must be odd and positive and less than 32.

**Scale: **Indicates the scale value for the computed
derivative values. The scale value helps to visualize a derivative in an
image.

In this example, three different outputs are obtained by changing the derivative value.