IMAQ Clamp Horizontal Max VI

LabView NI Vision

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IMAQ Clamp Horizontal Max VI

Owning Palette: Measure DistancesInstalled With: NI Vision Development Module

Measures a distance in the horizontal direction, from the vertical sides of the search area towards the center of the search area. This VI locates edges along a set of parallel search lines, or rake. The edges are determined based on their contrast and slope.

Details Examples

IMAQ Clamp Horizontal Max

Settings is a cluster defining the parameters of the edge detection algorithm and the information that is overlaid on the result image. The first three parameters specify the filter used to detect the edges.

	Contrast specifies the threshold for the contrast of the edge. Only edges with a contrast greater than this value are used in the detection process. Contrast is defined as the difference between the average pixel intensity before the edge and the average pixel intensity after the edge.
	Filter width specifies the number of pixels that the VI averages to find the contrast at either side of the edge.
	Steepness specifies the slope of the edge. This value represents the number of pixels that correspond to the transition area of the edge.
	Subsampling Ratio specifies the number of pixels that separate two consecutive search lines of the rake.
	Show Search Area determines whether the search area is overlaid on the image.
	Show Search Lines determines whether the search lines used to locate the edges are overlaid on the image.
	Show Edges Found determines whether the locations of the edges found are overlaid on the result image.
	Show Result determines whether the hit lines to the object are overlaid on the result image.

Image is a reference to the source image.

Rectangle specifies the coordinates of a rectangular search area.

	Left is the x-coordinate of the upper left corner of the rectangle.
	Top is the y-coordinate of the upper left corner of the rectangle.
	Right is the x-coordinate of the bottom right corner of the rectangle.
	Bottom is the y-coordinate of the bottom right corner of the rectangle.
	Rotation specifies the rotation angle in degrees of the rectangle with its center as point of rotation. If the rotation angle does not equal zero, the Left, Top, Right, and Bottom coordinates are not the actual coordinates of the upper left and bottom right corner of the rectangle, but their position if the rotation angle equals zero.

Coordinate System specifies the coordinate system to which the Rectangle is linked. If the Coordinate System input is used (connected), the location of the intensity measurement is shifted and rotated by the difference between the reference position of the coordinate system and its new location.

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.

Edge Coordinates is an array of point clusters consisting of the spatial coordinates of the detected edges.

Image Out is a reference to the destination image. The search area and/or the result of the measurement may be overlaid on the image according to the settings.

Distance returns the distance measured between the hit lines.

Coordinate System (duplicate) is a reference to the coordinate system.

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.

Details

A vertical hit-line to the object is calculated through the leftmost edge detected. A second vertical hit-line to the object is calculated through the rightmost edge. The distance between those two lines is returned. IMAQ Clamp Horizontal Max can overlay on the image returned: the position of the search area, the search lines, the edges found, and the result.

Examples

Refer to the following for an example that uses this VI.

LabVIEW\examples\Vision\2. Functions\Caliper\Clamp Example.vi

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