Class: ObjectTracker

ObjectTracker

new ObjectTracker(opt_classifiers)

ObjectTracker utility.
Parameters:
Name Type Description
opt_classifiers string | Array.<(string|Array.<number>)> Optional object classifiers to track.
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Extends

Members

edgesDensity :number

Specifies the edges density of a block in order to decide whether to skip it or not.
Type:
  • number
Default Value:
  • 0.2
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initialScale :number

Specifies the initial scale to start the feature block scaling.
Type:
  • number
Default Value:
  • 1.0
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on

Adds a listener to the end of the listeners array for the specified event.
Inherited From:
Source:

scaleFactor :number

Specifies the scale factor to scale the feature block.
Type:
  • number
Default Value:
  • 1.25
Source:

stepSize :number

Specifies the block step size.
Type:
  • number
Default Value:
  • 1.5
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Methods

addListener(event, listener) → {object}

Adds a listener to the end of the listeners array for the specified event.
Parameters:
Name Type Description
event string
listener function
Inherited From:
Source:
Returns:
Returns emitter, so calls can be chained.
Type
object

emit(event, opt_args) → {boolean}

Execute each of the listeners in order with the supplied arguments.
Parameters:
Name Type Description
event string
opt_args * [arg1], [arg2], [...]
Inherited From:
Source:
Returns:
Returns true if event had listeners, false otherwise.
Type
boolean

getClassifiers() → {TypedArray.<number>}

Gets the tracker HAAR classifiers.
Source:
Returns:
Type
TypedArray.<number>

getEdgesDensity() → {number}

Gets the edges density value.
Source:
Returns:
Type
number

getInitialScale() → {number}

Gets the initial scale to start the feature block scaling.
Source:
Returns:
Type
number

getScaleFactor() → {number}

Gets the scale factor to scale the feature block.
Source:
Returns:
Type
number

getStepSize() → {number}

Gets the block step size.
Source:
Returns:
Type
number

listeners(event) → {array}

Returns an array of listeners for the specified event.
Parameters:
Name Type Description
event string
Inherited From:
Source:
Returns:
Array of listeners.
Type
array

once(event, listener) → {object}

Adds a one time listener for the event. This listener is invoked only the next time the event is fired, after which it is removed.
Parameters:
Name Type Description
event string
listener function
Inherited From:
Source:
Returns:
Returns emitter, so calls can be chained.
Type
object

removeAllListeners(event) → {object}

Removes all listeners, or those of the specified event. It's not a good idea to remove listeners that were added elsewhere in the code, especially when it's on an emitter that you didn't create.
Parameters:
Name Type Description
event string
Inherited From:
Source:
Returns:
Returns emitter, so calls can be chained.
Type
object

removeListener(event, listener) → {object}

Remove a listener from the listener array for the specified event. Caution: changes array indices in the listener array behind the listener.
Parameters:
Name Type Description
event string
listener function
Inherited From:
Source:
Returns:
Returns emitter, so calls can be chained.
Type
object

setClassifiers(classifiers)

Sets the tracker HAAR classifiers.
Parameters:
Name Type Description
classifiers TypedArray.<number>
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setEdgesDensity(edgesDensity)

Sets the edges density.
Parameters:
Name Type Description
edgesDensity number
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setInitialScale(initialScale)

Sets the initial scale to start the block scaling.
Parameters:
Name Type Description
initialScale number
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setMaxListeners(n)

By default EventEmitters will print a warning if more than 10 listeners are added for a particular event. This is a useful default which helps finding memory leaks. Obviously not all Emitters should be limited to 10. This function allows that to be increased. Set to zero for unlimited.
Parameters:
Name Type Description
n number The maximum number of listeners.
Inherited From:
Source:

setScaleFactor(scaleFactor)

Sets the scale factor to scale the feature block.
Parameters:
Name Type Description
scaleFactor number
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setStepSize(stepSize)

Sets the block step size.
Parameters:
Name Type Description
stepSize number
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track(pixels, width, height)

Tracks the `Video` frames. This method is called for each video frame in order to emit `track` event.
Parameters:
Name Type Description
pixels Uint8ClampedArray The pixels data to track.
width number The pixels canvas width.
height number The pixels canvas height.
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