IMAQ GetPointsOnContour VI

LabView NI Vision

IMAQ GetPointsOnContour VI

Owning Palette: Analytic GeometryInstalled With: NI Vision Development Module

Finds the number of edge segments in an image and returns the coordinates of the pixels in each segment. Any pixel that is greater than zero is considered an edge location. This VI joins adjoining edge pixels into edge segments. An edge segment is considered closed if it forms a loop. Each edge segment is given a weight based on the pixel gray values along that edge. An edge segment with high gray values has a higher weight.

IMAQ GetPointsOnContour

Image (Edge Image) is the reference to the source image.

error in (no error) describes the error status before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. This VI or function runs normally only if no error occurred before this VI or function runs. If an error occurs while this VI or function runs, it runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node.

	status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE.
	code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
	source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.

Segment Information is an array of clusters containing the following information:

Number of Points is the number of points that make up the edge segment.

Open/Closed indicates whether the edge segment is open or closed.

Weight indicates the significance of the edge in terms of the gray values that constitute the edge.

Contour Points is an array of clusters, where each point on the edge is represented by the following coordinates:

	X returns the x-coordinate value of the edge point in the image.
	Y returns the y-coordinate value of the edge point in the image.
	Curvature returns the change in slope at this edge point of the segment.
	X Displacement returns the x displacement of the current edge pixel from a cubic spline fit of the current edge segment.
	Y Displacement returns the y displacement of the current edge pixel from a cubic spline fit of the current edge segment.

Number of Segments returns the number of edge segments in the image.

error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, it describes the error status that this VI or function produces. Right-click the error out indicator on the front panel and select Explain Error from the shortcut menu for more information about the error.

	status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred.
	code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
	source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.

previous page start next page