Class: ColorTracker

ColorTracker

new ColorTracker(opt_colors)

ColorTracker utility to track colored blobs in a frrame using color difference evaluation.
Parameters:
Name Type Description
opt_colors string | Array.<string> Optional colors to track.
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Extends

Members

colors :Array.<string>

Holds the colors to be tracked by the `ColorTracker` instance.
Type:
  • Array.<string>
Default Value:
  • ['magenta']
Source:

minDimension :number

Holds the minimum dimension to classify a rectangle.
Type:
  • number
Default Value:
  • 20
Source:

minGroupSize :number

Holds the minimum group size to be classified as a rectangle.
Type:
  • number
Default Value:
  • 30
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on

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

<static> getColor(name) → {function}

Gets the known color function that is able to test whether an (r,g,b) is the desired color.
Parameters:
Name Type Description
name string The color name.
Source:
Returns:
The known color test function.
Type
function

<static> registerColor(name, fn)

Registers a color as known color.
Parameters:
Name Type Description
name string The color name.
fn function The color function to test if the passed (r,g,b) is the desired color.
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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

getColors() → {Array.<string>}

Gets the colors being tracked by the `ColorTracker` instance.
Source:
Returns:
Type
Array.<string>

getMinDimension(minDimension)

Sets the minimum dimension to classify a rectangle.
Parameters:
Name Type Description
minDimension number
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getMinGroupSize() → {number}

Gets the minimum group size to be classified as a rectangle.
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

setColors(colors)

Sets the colors to be tracked by the `ColorTracker` instance.
Parameters:
Name Type Description
colors Array.<string>
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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:
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setMinDimension() → {number}

Sets the minimum dimension to classify a rectangle.
Source:
Returns:
Type
number

setMinGroupSize(minGroupSize)

Sets the minimum group size to be classified as a rectangle.
Parameters:
Name Type Description
minGroupSize 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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