Table Of Contents

Overlay Element (Overlay Multiple Lines) (G Dataflow)

Last Modified: October 25, 2017

Overlays multiple lines, as either a polyline or a polygon, on an image.

connector_pane_image
datatype_icon

group name

Group to which you want to add the overlay information.

If no name is specified, the overlay information is added to the default group.

datatype_icon

image in

Reference to the source image.

datatype_icon

line endpoints

Array of the point-coordinate clusters defining the ends of the lines to overlay.

datatype_icon

X

X-coordinate of a point in the array.

datatype_icon

Y

Y-coordinate of a point in the array.

datatype_icon

drawing mode

Parameter specifying whether to draw only the frame of the polygon or fill in the polygon.

Default: Frame

datatype_icon

width

Width of the overlay in pixels.

datatype_icon

error in

Error conditions that occur before this node runs.

The node responds to this input according to standard error behavior.

Standard Error Behavior

Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

error in does not contain an error error in contains an error
If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Default: No error

datatype_icon

color

Color of the overlay.

The alpha color channel is not supported. Setting the color to transparent has the same effect as selecting black.

datatype_icon

maintain width

Boolean that specifies to measure the overlay in screen pixels or image pixels.

Overlays measured in screen pixels maintain the same width as you zoom in on the image. Overlays measured in image pixels will scale with the image and appear to increase in width as you zoom in on the image.

TRUE Measures the overlay in screen pixels.
FALSE Measures the overlay in image pixels.

Default: FALSE

datatype_icon

image out

Reference to the destination image.

If image dst is connected, image dst out is the same as image dst. Otherwise, image dst out refers to the image referenced by image src.

datatype_icon

error out

Error information.

The node produces this output according to standard error behavior.

Standard Error Behavior

Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

error in does not contain an error error in contains an error
If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Characteristics of Overlays

Overlays are nondestructive, which means that they do not overwrite the underlying pixel values. You can save overlay information with an image by using the Read Image and Vision Information node. If you want to replace the underlying pixel values with the overlay values, use the Merge Overlay node.

Where This Node Can Run:

Desktop OS: Windows

FPGA: Not supported

Web Server: Not supported in VIs that run in a web application


Recently Viewed Topics