CannyEdge
The CannyEdge block finds the edges of objects using Canny Edge detection.
Library
ComputerVision/Images/Detection
Description
CannyEdge uses thresholds to determine if pixels are part of an edge.
- Edges with an intensity gradient greater than the specified upper threshold are edges.
- Edges with an intensity gradient lower than the lower threshold are non-edges and are discarded.
- Edges with an intensity gradient between the two thresholds are classified as edges based on their connectivity. That is, if they are connected to “sure-edge” pixels, they are classified as part of edges. Otherwise, they are discarded.
Because edge detection can be affected by noise, you may want to apply a Gaussian blur (or filter) to the image before it is read into the CannyEdge block.
Parameters
| Name | Label | Description | Data Type | Valid Values |
|---|---|---|---|---|
lowerThreshold | Lower Threshold | Specifies the lower threshold. Edges with an intensity gradient lower than the Lower Threshold are discarded. | Scalar | |
upperThreshold | Upper Threshold | Specifies the upper threshold. Edges with an intensity gradient greater than the Upper Threshold are retained. | Scalar | |
externalActivation | External activation | This parameter defines if the block receives or inherits an external activation. When External Activation is used, an additional activation port is added to the block. Default is OFF. | Number | 0 |
Ports
| Name | Type | Description | IO Type | Number |
|---|---|---|---|---|
src | explicit | input | 1 | |
image | explicit | output | 1 | |
Port 3 | activation | input | externalActivation |