Optical Flow (Optical Flow (LKP)) (G Dataflow)

Reference to the current source image.

Reference to the previous source image.

Array of points that need to be tracked.

x

X-coordinate of the point.

y

Y-coordinate of the point.

Options that are used to track the features between two successive frames.

level

Number of pyramid levels to use.

max. iterations

Number of iterations to run the tracking algorithm at each level.

window size

Region around each input feature point that is used to search for a match.

displacement threshold

Minimum allowed displacement between the location of the tracked features from iteration to iteration. That is, if the position of a feature does not move more than the displacement threshold from its location on a previous iteration, the current location of the feature is finalized and it is not tracked anymore.

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

Coefficients of the filter that is used to smooth the image. The kernel coefficients must be symmetric.

Duplicate of the input current frame.

Distance between feature points in and feature points out.

Array of points that represent the new locations of the input feature points in.

x

X-coordinate of the point.

y

Y-coordinate of the point.

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.