API Docs (Java)

Overview

Name	type	Description
GazeTracker	class	A class that generates gaze tracking data
CameraPosition	class	Information of the screen origin for the camera to be set in GazeTracker
GazeInfo	class	A class composed of information about eye tracking
FaceInfo	class	A class composed of information about face.
UserStatusOption	class	The class contains User Status options information for GazeTracker
InitializationCallback	interface	A callback interface that notifies the result when creating a gaze tracker
GazeTrackerCallback	interface	All callbacks used in GazeTracker instance inherit from GazeTrackerCallback
StatusCallback	interface	An interface that informs whether the Gaze Tracker is operating or not
GazeCallback	interface	An interface to receive frame-by-frame GazeInfo
FaceCallback	interface	An interface to receive frame-by-frame FaceInfo
CalibrationCallback	interface	An interface used in the calibration process
UserStatusCallback	interface	An interface used for user status function
ImageCallback	interface	An interface that receives the image buffer from the front camera
InitializationErrorType	enum	An enum that contains error types of InitializationCallback
StatusErrorType	enum	An enum that contains error types of StatusCallback
TrackingState	enum	An enum that contains tracking state types of GazeInfo
EyeMovementState	enum	An enum that contains eye movement state types using at GazeInfo
ScreenState	enum	An enum that contains screen state types using at GazeInfo
CalibrationModeType	enum	An enum that contains calibration mode types of startCalibartion
AccuracyCriteria	enum	An enum that contains accuracy criteria of startCalibartion

---

GazeTracker

public class GazeTracker

GazeTracker is the class that generates gaze tracking data from the video from the device's front camera.

Summary

Constructor and Destructor
initGazeTracker
initGazeTracker (with User Status Options)
deinitGazeTracker

Functions
getVersionName
startTracking
stopTracking
isTracking
isDeviceFound
addCameraPosition
getCameraPosition
getCameraPositionList
selectCameraPosition
setStatusCallback
removeStatusCallback
setGazeCallback
removeGazeCallback
setFaceCallback
removeFaceCallback
setTrackingFPS
setCameraPreview
removeCameraPreview
startCalibration
stopCalibration
isCalibrating
startCollectSamples
setCalibrationData
setCalibrationCallback
removeCalibrationCallback
setAttentionInterval
getAttentionScore
setAttentionRegion
getattentionRegion
removeattentionRegion
setUserStatusCallback
removeUserStatusCallback
setCallbacks
setImageCallback
removeImageCallback

---

getVersionName

public static String getVersionName()

Parameters	Type	Description
versionName	string	SeeSo SDK Version

Example

String version = GazeTracker.getVersionName();
System.out.println("SeeSo version :" + version);

---

initGazeTracker

public static void initGazeTracker(
    Context context, String licenseKey, InitializationCallback callback)

GazeTracker construction process includes authentication.

This Function is asynchronous.

The created GazeTracker instance is delivered through InitializationCallback.

Parameters	Type	Description
context	android.content.Context
licenseKey	String	Key generated from SeeSo console page
callback	InitializationCallback	Initialized after alert Callback

Example

// Implement InitializationCallback
InitializationCallback initializationCallback = new InitializationCallback() {
  @Override
  public void onInitialized(GazeTracker gazeTracker, InitializationErrorType error) {
    if (gazeTracker != null) {
        // gazeTracker init success
    } else {
        // gazeTracker init fail
    }
  }
};

GazeTracker.initGazeTracker(context, "YOUR_LICENSE_KEY", initializationCallback);

---

initGazeTracker (with User Status Options)

public static void initGazeTracker(Context context, String licenseKey, InitializationCallback callback, UserStatusOption option)

GazeTracker construction requires authentication.

The function is asynchronous.

The created GazeTracker instance is delivered through InitializationCallback.

To use user status option, initialize using UserStatus.

Parameters	Type	Description
context	android.content.Context
licenseKey	String	Key generated from SeeSo console page
callback	InitializationCallback	Initialized after alert Callback
option	UserStatusOption	It contains data about the function among the user status to be used

Example

// Implement InitializationCallback
InitializationCallback initializationCallback = new InitializationCallback() {
  @Override
  public void onInitialized(GazeTracker gazeTracker, InitializationErrorType error) {
    if (gazeTracker != null) {
        // gazeTracker init success
    } else {
        // gazeTracker init fail
    }
  }
};

UserStatusOption userStatusOption = new UserStatusOption();

if (isStatusAttention) {
  userStatusOption.useAttention();
}
if (isStatusBlink) {
  userStatusOption.useBlink();
}
if (isStatusDrowsiness) {
  userStatusOption.useDrowsiness();
}

GazeTracker.initGazeTracker(context, "YOUR_LICENSE_KEY", initializationCallback, userStatusOption);

---

deinitGazeTracker

public static void deinitGazeTracker(GazeTracker gazeTracker)

After this is called, do not call gazeTracker's methods.

For memory optimization, assigning null to the destructed object is recommended.

Parameters	Type	Description
gazeTracker	GazeTracker	GazeTracker instance

Example

// Implement InitializationCallback
InitializationCallback initializationCallback = new InitializationCallback() {
  @Override
  public void onInitialized(GazeTracker gazeTracker, InitializationErrorType error) {
    if (gazeTracker != null) {
      // gazeTracker init success

      // you can deinit gazeTracker instance
      GazeTracker.deinitGazeTracker(gazeTracker);
      gazeTracker = null;

    } else {
      // gazeTracker init fail
    }
  }
};

GazeTracker.initGazeTracker(context, "YOUR_LICENSE_KEY", initializationCallback);

---

startTracking

public synchronized void startTracking()

This function should be called before starting gaze-tracking.

On successful start, StatusCallback.onStarted() is called.

Example

private InitializationCallback initializationCallback = new InitializationCallback() {
  @Override
    public void onInitialized(GazeTracker gazeTracker, InitializationErrorType error) {
      if (gazeTracker != null) {
        // gazeTracker init success

        // set StatusCallback
        gazeTracker.setCallbacks(statusCallback);

        // startTracking
        gazeTracker.startTracking();

      } else {
        // gazeTracker init fail
      }
  }
};

private StatusCallback statusCallback = new StatusCallback() {
  @Override
  public void onStarted() {
    // gazeTracker.startTracking() Success
  }

  @Override
  public void onStopped(final StatusErrorType error) {
    // gazeTracker.startTracking() Fail
  }
};

GazeTracker.initGazeTracker(context, "YOUR_LICENSE_KEY", initializationCallback);

---

stopTracking

public synchronized void stopTracking()

This function is called to stop gaze tracking.

On successful stop, StatusCallback.onStopped() is called.

Example

// Implement StatusCallback and already set callback to gazeTracker
private StatusCallback statusCallback = new StatusCallback() {
  @Override
  public void onStarted() {

  }

  @Override
  public void onStopped(final StatusErrorType error) {
    // gazeTracker.stopTracking() Success
  }
};

gazeTracker.stopTracking();

---

isTracking

public synchronized boolean isTracking()

This function represents the status of gaze tracking. It returns true when gaze tracking is working, false when gaze tracking is stopped.

Return Type	Description
boolean	It is a return value indicating whether the tracking state is present

Example

boolean isTracking = gazeTracker.isTracking();
System.out.println("Tracking state : " + isTracking);

isDeviceFound

public boolean isDeviceFound()

Return Type	Description
boolean	if it was true, device was founded

Example

boolean isFound = tracker.isDeviceFound();
System.out.println("isDeviceFound " + isFound);

---

addCameraPosition

public void addCameraPosition(CameraPosition cameraPosition)

Add CameraPosition to GazeTracker instance.

Parameters	Type	Description
cameraPosition	CameraPosition	CameraPosition class

Example

CameraPosition cameraPosition = new CameraPosition("SM-T720", 1600f, 2560f, -72f, -4f);// tab s5e
tracker.addCameraPosition(cameraPosition);

---

getCameraPosition

public CameraPosition getCameraPosition()

Return Type	Description
CameraPosition	CameraPosition class

Example

CameraPosition cameraPosition = tracker.getCameraPosition();
System.out.println(cameraPosition.modelName + " : " + cameraPosition.screenOriginX + " : " + cameraPosition.screenOriginY);

---

getCameraPositionList

public ArrayList<CameraPosition> getCameraPositionList()

Return Type	Description
ArrayList<CameraPosition>	ArrayList of CameraPosition of the device. A device can have multiple CameraPosition (ex. Galaxy Fold)

Example

ArrayList<CameraPosition> cameraPositionList = tracker.getCameraPositionList();
for (CameraPosition cameraPosition : cameraPositionList) {
  System.out.println(cameraPosition.modelName + " : " + cameraPosition.screenOriginX + " : " + cameraPosition.screenOriginY);
}

selectCameraPosition

public void selectCameraPosition(int idx)

Parameters	Type	Description
idx	Int	Index of the CameraPosition to use from getCameraPositionList().

Example

tracker.selectCameraPosition(0);

setStatusCallback

public void setStatusCallback(StatusCallback callback)

Set StatusCallback implementations to gazeTracker.

Parameters	Type	Description
callback	StatusCallback	Callback implementation of the StatusCallback.

Example

//implement statusCallback
gazeTracker.setStatusCallback(statusCallback);

---

removeStatusCallback

public void removeStatusCallback()

Remove all StatusCallback implementations set in gazeTracker.

---

setGazeCallback

public void setGazeCallback(GazeCallback callback)

Set GazeCallback implementations to gazeTracker.

Parameters	Type	Description
gazeTracker	GazeCallback	Callback implementation of the GazeCallback

Example

//implement gazeCallback
private GazeCallback gazeCallback = new GazeCallback() {
  @Override
  public void onGaze(final GazeInfo gazeInfo) {
    // do something
  }
};

gazeTracker.setGazeCallback(gazeCallback);

---

removeGazeCallback

public void removeGazeCallback()

Remove all GazeCallback listeners.

Example

gazeTracker.removeGazeCallback();

---

setFaceCallback

public void setFaceCallback(FaceCallback faceCallback)

Set FaceCallback implementations to gazeTracker.

Parameters	Type	Description
gazeTracker	FaceCallback	Callback implementation of the FaceCallback

Example

//implement faceCallback
private FaceCallback faceCallback = new FaceCallback() {
  @Override
  public void onFace(FaceInfo faceInfo) {
    // do something
  }
};

gazeTracker.setFaceCallback(faceCallback);

---

removeFaceCallback

public void removeFaceCallback()

Remove all FaceCallback listeners.

Example

gazeTracker.removeFaceCallback();

---

setTrackingFPS

public boolean setTrackingFPS(int fps)

Limits the maximum FPS of the gaze tracking.
FPS should be between 1 and 30.

FPS can be dropped due to device spec.
The default value is 30.

Parameters	Type	Description
fps	int	Upper bound of FPS(Frame Per Second) for gaze tracking

Return Type	Description
boolean	Whether it is applied at the set fps is returned as a result

Example

gazeTracker.setTrackingFPS(20);

---

setCameraPreview

public void setCameraPreview(android.view.TextureView cameraPreview)

Parameters	Type	Description
cameraPreview	android.view.TextureView	TextureView for camera preview

Example

TextureView preview = findViewById(R.id.preview);
gazeTracker.setCameraPreview(preview);

---

removeCameraPreview

public void removeCameraPreview()

Remove registered camera preview.

Example

gazeTracker.removeCameraPreview();

---

startCalibration

public boolean startCalibration(CalibrationModeType mode, AccuracyCriteria criteria, float left, float top, float right, float bottom)
public boolean startCalibration(CalibrationModeType mode, float left, float top, float right, float bottom)
public boolean startCalibration(CalibrationModeType mode)
public boolean startCalibration(float left, float top, float right, float bottom)
public boolean startCalibration(AccuracyCriteria criteria)
public boolean startCalibration(CalibrationModeType mode, AccuracyCriteria criteria)
public boolean startCalibration()

It returns true when parameters are valid.

It also returns false when the calibration region has been set outside of the device screen.

The false return will block the calibration process.

Parameters	Type	Description
mode	CalibrationModeType	Can select the calibration option. DEFAULT(=FIVE_POINT), ONE_POINT, FIVE_POINT, SIX_POINT
left	float	Region that needs calibration. The unit is px (default is 80% region of device screen)
top	float	Region that needs calibration. The unit is px (default is 80% region of device screen)
right	float	Region that needs calibration. The unit is px (default is 80% region of device screen)
bottom	float	Region that needs calibration. The unit is px (default is 80% region of device screen)
criteria	AccuracyCriteria	Option that manage calibration process and accuracy. Three options - DEFAULT, LOW, HIGH - are available. Default is DEFAULT

Return Type	Description
boolean	It returns true when parameters are valid

Example

//implement calibrationCallback
private CalibrationCallback calibrationCallback = new TimeoutCalibrationCallback() {

@Override
public void onCalibrationProgress(final float progress) {
  runOnUiThread(new Runnable() {
    @Override
    public void run() {
      // process calibration point UI
    }
  });
}

@Override
public void onCalibrationNextPoint(final float x, final float y) {
  runOnUiThread(new Runnable() {
    @Override
    public void run() {
      // draw calibration point to (x,y)
    }
  });
  handler.postDelayed(new Runnable() {
    @Override
    public void run() {
      // After drawing the calibration point,
      // call startCollectSamples after enough time (1,000 ms in this example) that considering user can recognize the point
      gaze.startCollectSamples();
    }
  }, 1000);
}

@Override
public void onCalibrationFinished(double[] calibrationData) {
  // saveCalibration(calibrationData);
  runOnUiThread(
    new Runnable() {
      @Override
      public void run() {
        //remove calibration UI
      }
    });
  }
};

gazeTracker.setCalibrationCallback(calibrationCallback);

// Example of using overloaded functions
boolean startedResult = gazeTracker.startCabliration(CalibrationModeType.ONE_POINT, 100, 100, 1000, 1200);
boolean startedResult = gazeTracker.startCabliration(CalibrationModeType.ONE_POINT);
boolean startedResult = gazeTracker.startCabliration(100, 100, 1000, 1200);
boolean startedResult = gazeTracker.startCabliration();

---

stopCalibration

public void stopCalibration()

Stop calibration.

---

isCalibrating

public boolean isCalibrating()

Return true when calibrating, false otherwise.

Return Type	Description
boolean	It returns true when calibrating

startCollectSamples

public boolean startCollectSamples()

This relays the coordinates of the point that should be seen when calibration is in progress at the function: CalibrationCallback.onCalibrationNextPoint.

You should display coordinates on the screen and call startCollectSamples for calibration.

Return Type	Description
boolean	It returns true when calibrating

---

setCalibrationData

public boolean setCalibrationData(double[] calibrationData)

Set existing calibration data to gazeTracker.

Parameters	Type	Description
calibrationData	double[]	Calibration Data

Return Type	Description
boolean	Calibration Data loaded result

Example

//implement calibrationCallback
private CalibrationCallback calibrationCallback = new TimeoutCalibrationCallback() {

  @Override
  public void onCalibrationFinished(double[] calibrationData) {
    // After calibration is finished, the data is automatically reflected in the current gazeTracker instance.
    // You can save it and apply the saved value to the new gazeTracker instance when you restart the app later.
    // savedCalibrationData = calibrationData;
  }
};

gazeTracker.setCalibrationData(savedCalibrationData);

---

setCalibrationCallback

public void setCalibrationCallback(CalibrationCallback callback)

Set CalibrationCallback implementations to gazeTracker.

Parameters	Type	Description
callback	CalibrationCallback	Callbacks implementation of the CalibrationCallback

Example

//implement calibrationCallback
private CalibrationCallback calibrationCallback = new TimeoutCalibrationCallback() {

@Override
public void onCalibrationProgress(final float progress) {
  runOnUiThread(new Runnable() {
    @Override
    public void run() {
      // process calibration point UI
    }
  });
}

@Override
public void onCalibrationNextPoint(final float x, final float y) {
  runOnUiThread(new Runnable() {
    @Override
    public void run() {
      // draw calibration point to (x,y)
    }
  });
  handler.postDelayed(new Runnable() {
    @Override
    public void run() {
      // After drawing the calibration point,
      // call startCollectSamples after enough time (1,000 ms in this example) that considering user can recognize the point
      boolean isStart = gaze.startCollectSamples();
    }
  }, 1000);
}

@Override
public void onCalibrationFinished(double[] calibrationData) {
  // saveCalibration(calibrationData);
  runOnUiThread(
    new Runnable() {
      @Override
      public void run() {
        //remove calibration UI
      }
    });
  }
};

gazeTracker.setCalibrationCallback(calibrationCallback);

---

removeCalibrationCallback

public void removeCalibrationCallback()

Remove all CalibrationCallback implementations set in gazeTracker.

---

setAttentionInterval

public void setAttentionInterval(int interval)

Set time interval for the UserStatusCallback.onAttention callback.

The UserStatus Attention score will be calculated for the given time interval.

The beginning and ending timestamps are passed through the onAttention callback as timestampBegin and timestampEnd.

The interval range is 10 to 60 (seconds), and the default value is 30 seconds.

Parameters	Type	Description
interval	int	Time interval for the UserStatus Attention score

Example

private InitializationCallback initializationCallback = new InitializationCallback() {
  @Override
  public void onInitialized(GazeTracker gazeTracker, InitializationErrorType error) {
    if (gazeTracker != null) {
      // gazeTracker init success
      // set StatusCallback

      gazeTracker.setCallbacks(statusCallback);
      // set UserStatus Attention Interval
      gazeTracker.setAttentionInterval(30);
    } else {
      // gazeTracker init fail
    }
  }
};

---

getAttentionScore

public float getAttentionScore()

Get current Attention score from the GazeTracker.

This API does not provide timestamp of the Attention score data.

Use onAttention callback, unless the Attention score is required at a specific time/location.

Return Type	Description
float	Current Attention score

---

setAttentionRegion

public void setAttentionRegion(float left, float top, float right, float bottom)

Set Attention ROI

Parameters	Type	Description
left	float	Left boundary of attention region. The unit is px
top	float	Top boundary of attention region. The unit is px
right	float	Right boundary of attention region. The unit is px
bottom	float	Bottom boundary of attention region. The unit is px

note

Device screen region is set as default.

Example

// Set attention region that (x,y) = (100,100), (width, height) = 100,100
setattentionRegion(100, 100, 200, 200);

---

getAttentionRegion

public float[] getAttentionRegion()

Return Type	Description
float[]	If the region is not set, returns an empty array. Otherwise, returns left, top, right, bottom passed from setAttentionRegion

---

removeAttentionRegion

public void removeAttentionRegion()

Remove Attention ROI

---

setUserStatusCallback

public void setUserStatusCallback(UserStatusCallback callback)

Parameters	Type	Description
callback	UserStatusCallback	Set UserStatusCallback implementations to gazeTracker.

Example

//implement gazeCallback
private UserStatusCallback userStatusCallback = new UserStatusCallback() {
  @Override
  public void onAttention(final long timestampBegin, final long timestampEnd, final float score) {}

  @Override
  public void onDrowsiness(final long timestamp, final boolean isDrowsiness) {}

  @Override
  public void onBlink(final long timestamp, final boolean isBlinkLeft, final boolean isBlinkRight, final boolean isBlink, final float eyeOpenness) {}
};
gazeTracker.setUserStatusCallback(userStatusCallback);

---

removeUserStatusCallback

public void removeUserStatusCallback()

Remove all UserStatusCallback implementations set in gazeTracker

---

setCallbacks

public void setCallbacks(GazeTrackerCallback callback...)

Set GazeTrackerCallback implementations to gazeTracker.

Parameters	Type	Description
callback	GazeTrackerCallback	Callbacks implementation of the GazeTrackerCallback.

Example

//implement statusCallback, gazeCallback, imageCallback, calibrationCallback, userStatusCallback
gazeTracker.setCallbacks(statusCallback, gazeCallback, imageCallback, calibrationCallback, userStatusCallback);

---

setImageCallback

public void setImageCallback(ImageCallback callback)

Set ImageCallback implementations to gazeTracker.

Parameters	Type	Description
callback	ImageCallback	Callbacks implementation of the ImageCallback.

Example

//implement imageCallback
private ImageCallback imageCallback = new ImageCallback() {
  @Override
  public void onImage(long timestamp, final byte[] buffer) {
    uiHandler.post(new Runnable() {
      @Override
      public void run() {
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        YuvImage yuvImage = new YuvImage(buffer, ImageFormat.NV21, 640, 480, null);
        yuvImage.compressToJpeg(new Rect(0, 0, 640, 480), 50, out);
        byte[] imageBytes = out.toByteArray();
        Bitmap image = BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.length);
        imgBuffer.setImageBitmap(image);
      }
    });
  }
};
gazeTracker.setImageCallback(imageCallback);

---

removeImageCallback

public void removeImageCallback()

Remove all ImageCallback implementations set in gazeTracker.

---

CameraPosition

public class CameraPosition {
  public String modelName;
  public float screenWidth;
  public float screenHeight;
  public float screenOriginX;
  public float screenOriginY;
  public boolean cameraOnLongerAxis;
}

This class indicates the relative position from the camera to the screen origin. GazeTracker uses the information to calculate gaze coordinate.

For more information, see gaze coordinate

Summary

Variables	type	description
modelName	String	Device model name
screenWidth	float	The current screen width size of the device being used, measured in pixels.
screenHeight	float	The current screen height size of the device being used, measured in pixels.
screenOriginX	float	X's Distance from the camera to the top left corner of the screen (mm)
screenOriginY	float	Y's Distance from the camera to the top left corner of the screen (mm)
cameraOnLongerAxis	boolean	A boolean value representing when the camera is placed on the device's long axis.

---

GazeInfo

public class GazeInfo {
  public long timestamp;
  public float x, y;
  public float fixationX, fixationY;
  public float leftOpenness, rightOpenness;
  public TrackingState trackingState;
  public EyeMovementState eyeMovementState;
  public ScreenState screenState;
}

A class composed of information about eye tracking.

Variables	type	description
timestamp	long	Timestamp of gaze point. The unit is millisecond. The time format is UTC
x	float	x coordinate value of gaze point. Origin is device screen. The unit is pixel(px)
y	float	y coordinate value of gaze point. Origin is device screen. The unit is pixel(px)
fixationX	float	x coordinate value of last fixation point. Origin is device screen. The unit is pixel(px)
fixationY	float	y coordinate value of last fixation point. Origin is device screen. The unit is pixel(px)
leftOpenness	float	openness degree of left eye(0.0~1.0). value will only return when userStatusOption in on
rightOpenness	float	openness degree of right eye(0.0~1.0). value will only return when userStatusOption in on
trackingState	TrackingState	SUCCESS, LOW_CONFIDENCE, UNSUPPORTED, FACE_MISSING
eyeMovementState	EyeMovementState	FIXATION, SACCADE, UNKNOWN
screenState	ScreenState	INSIDE_OF_SCREEN, OUTSIDE_OF_SCREEN, UNKNOWN

---

---

FaceInfo

public class FaceInfo {
  public long timestamp;
  public float score;
  public Size frameSize;
  public float left, top, right, bottom;
  public float pitch, yaw, roll;
  public float centerX, centerY, centerZ;
}

A class composed of information about eye tracking.

Variables	type	description
timestamp	long	Timestamp of gaze point. The unit is millisecond. The time format is UTC
score	float	Value of facial recognition confidence (0.0 ~ 1.0).
frameSize	android.util.Size	camera frame size.
left, top, right, bottom	float	It represents the location of the face with a rectangular box. The four sides of the box indicate the four positions of the face within the image.
pitch	float	Pitch is the rotation around the X-axis of an object. It is also known as the attitude angle. In aviation, it is often referred to as the nose-up or nose-down angle.
yaw	float	Yaw is the rotation around the Y-axis of an object. It is also known as the heading angle. In aviation, it is often referred to as the bearing or compass angle.
roll	float	Roll is the rotation around the Z-axis of an object. It is also known as the bank angle. In aviation, it is often referred to as the wing-up or wing-down angle.
centerX, centerY, centerZ	float	The x,y,z distance of the center of the face from the camera. The unit is mm.

warning

• When the camera is positioned at the top, we defined it as 0 degrees. (pitch, yaw, roll)

---

UserStatusOption

public class UserStatusOption

The class contains User Status options information for GazeTracker

Summary

functions
isUseAttention
isUseBlink
isUseDrowsiness
useAttention
useBlink
useDrowsiness
useAll

---

isUseAttention

isUseBlink

isUseDrowsiness

public boolean isUseAttention()
public boolean isUseBlink()
public boolean isUseDrowsiness()

Return Type	Description
boolean	Return true if the flag is on, false otherwise

---

useAttention

useBlink

useDrowsiness

public void useAttention()
public void useBlink()
public void useDrowsiness()

Set flags.

---

useAll

public void useAll()

Set All User Status flag.

---

InitializationCallback

public interface InitailizationCallback

Summary

function
onInitialized

---

onInitialized

public void onInitailzed(GazeTracker tracker, InitializationErrorType error);

This is callback function being called when GazeTracker.initGazeTracker function has been called.

See Authentication for more details.

Parameters	Type	Description
tracker	GazeTracker	GazeTracker Instance
error	InitializationErrorType	Error code

Example

public void onInitialized(GazeTracker tracker, InitializationErrorType error){
  if (tracker != null) {
    this.tracker = tracker;
  } else {
    switch (error) {
      case InitializationErrorType.ERROR_NONE:
        break;
      case InitializationErrorType.ERROR_INIT:
        break;

      ...
    }
  }
}

---

GazeTrackerCallback

public interface GazeTrackerCallback

Base interface for callbacks.

---

StatusCallback

public interface StatusCallback extends GazeTrackerCallback

Summary

function
onStarted
onStopped

---

onStarted

public void onStarted()

The function that automatically called after GazeTracker.startTracking() if initialization succeeds. Calibration is available after this.

Example

@Override
public void onStarted() {
  gazeTracker.startCalibration();
}

---

onStopped

public void onStopped(StatusErrorType error)

Parameters	type	Description
error	StatusErrorType	Error code

Example

@Override
public void onStopped(StatusErrorType error) {
  if (error != StatusCallback.ERROR_NONE) {
    // onStopped with error
  } else {
    // onStopped without error
  }
}

---

GazeCallback

public interface GazeCallback extends GazeTrackerCallback

Summary

Function
onGaze

---

onGaze

public void onGaze(GazeInfo gazeInfo)

Parameters	Type	Description
gazeInfo	GazeInfo	Passing the gaze info value according to the frame

Example

private GazeCallback gazeCallback = new GazeCallback() {
  @Override
  public void onGaze(final GazeInfo gazeInfo) {

  }
};

gazeTracker.setCallbacks(gazeCallback);

---

---

FaceCallback

public interface FaceCallback extends GazeTrackerCallback

Summary

Function
onFace

---

onFace

public void onFace(FaceInfo faceInfo)

Parameters	Type	Description
faceInfo	FaceInfo	Passing the face info value according to the frame

Example

private FaceCallback faceCallback = new FaceCallback() {
  @Override
  public void onFace(final FaceInfo faceInfo) {

  }
};

gazeTracker.setCallbacks(faceCallback);

---

CalibrationCallback

public interface CalibrationCallback extends GazeTrackerCallback

Summary

Functions
onCalibrationNextPoint
onCalibrationProgress
onCalibrationFinished

---

onCalibrationNextPoint

public void onCalibrationNextPoint(float x, float y)

The x, y coordinate value of the gaze point that should be focused on during the calibration process.

Also, a proper UI should be on screen for notify the calibration target point.

You should call startCollectSamples to process the calibration.

Parameters	Type	Description
x	float	The x coordinate value of the gaze point that should be focused on during the calibration process. Origin is the device screen. The unit is pixel(px)
y	float	The Y coordinate value of the gaze point that should be focused on during the calibration process. Origin is the device screen. The unit is pixel(px)

Example

@Override
public void onCalibrationNextPoint(float x, float y) {
  // Draw Calibration Point(x,y) in view.

  // than call startCollectSamples to proceed calibration.
  gazeTracker.startCollectSamples();
}

---

onCalibrationProgress

public void onCalibrationProgress(float progress)

This is callback that represent the calibration progression.
The value will be between 0.0 and 1.0.

The value increases when startCollectSamples function is called.

Parameters	Type	Description
progress	float	Calibration progression for each point

note

Visualizing the calibration progression with proper UI is recommended to improve UX.

---

onCalibrationFinished

public void onCalibrationFinished(double[] calibrationData)

This is callback function that notify when all calibration step finished.

The calibrationData passed as a parameter has already been applied to GazeTracker.

You can save it for later use.

E.g: Not re-calibrating when restarting the app, by passing the stored data via GazeTracker.setCalibrationData.

Parameters	Type	Description
calibrationData	double[]	Calibration data

Example

public void onCalibrationFinished(double[] calibrationData) {
  // remove calibration UI, save calibration data
  removeCalibrationUI();
  saveCalibrationDataForLaterUse(calibrationData);
}

---

UserStatusCallback

public interface UserStatusCallback extends GazeTrackerCallback

The User Status includes Attention, Drowsiness, and Blink.

1. Attention: How much the user attention is focused on the screen content for interval time (0.0 ~ 1.0)

2. Drowsiness: If the user feel drowsiness (True/False)

3. Blink: If the user blink eyes (left eye, right eye, general(both eyes))

Summary

Functions
onAttention
onDrowsiness
onBlink

---

onAttention

  public void onAttention(long timestampBegin, long timestampEnd, float score)

1. Timestamp range of the data will be passed as timestampBegin and timestampEnd.
2. The default time interval is 30 seconds(see setAttentionInterval).
3. If the user attention level is low, score will be close to 0.0.
4. If the user attention level is high, score will be close to 1.0.

Parameters	Type	Description
timestampBegin	long	Beginning Timestamp of the data
timestampEnd	long	Ending Timestamp of the data
score	float	User Attention rate score between the timestamps

Example

private UserStatusCallback userStatusCallback = new UserStatusCallback() {
  @Override
  public void onAttention(long timestampBegin, long timestampEnd, float score) {
    // do something
  }
};

gazeTracker.setUserStatusCallback(userStatusCallback);

---

onDrowsiness

  public void onDrowsiness(long timestamp, boolean isDrowsiness, float intensity)

1. Timestamp of the data will be passed as timestamp.
2. isDrowsiness is true if the user seems drowsy, false otherwise.
3. intensity parameter represents the level of drowsiness, ranging from 0 to 1, where a value closer to 0 indicates no drowsiness and a value closer to 1 indicates a high intensity of drowsiness.

Parameters	Type	Description
timestamp	long	Timestamp of the data
isDrowsiness	boolean	User drowsiness flag
intensity	float	Level of drowsiness intensity (0 to 1)

Example

private UserStatusCallback userStatusCallback = new UserStatusCallback() {
  @Override
  public void onDrowsiness(final long timestamp, final boolean isDrowsiness, final float intensity) {
    // do something
  }
};

gazeTracker.setUserStatusCallback(userStatusCallback);

---

onBlink

public void onBlink(long timestamp, boolean isBlinkLeft, boolean isBlinkRight, boolean isBlink, float leftOpenness, float rightOpenness)

1. Timestamp of the data will be passed as timestamp.
2. isBlinkLeft is true if the user blinks their left eye, false otherwise.
3. isBlinkRight is true if the user blinks their right eye, false otherwise.
4. isBlink is true if one blinks their eye, false otherwise(This is a general blink condition).
5. If the user's eyes are wide open, leftOpenness, rightOpenness in onBlink callback will be close to 1.0.
6. If the user's eyes are closed, leftOpenness, rightOpenness in onBlink callback will be close to 0.0.

Parameters	Type	Description
timestamp	long	Timestamp of the data
isBlinkLeft	boolean	User left blink flag
isBlinkRight	boolean	User right blink flag
isBlink	boolean	User blink flag
leftOpenness	float	User left eye-openness rate
rightOpenness	float	User right eye-openness rate

Example

private UserStatusCallback userStatusCallback = new UserStatusCallback() {
  @Override
  public void onBlink(final long timestamp, final boolean isBlinkLeft, final boolean isBlinkRight, final boolean isBlink, final float eyeOpenness) {
    // do something
  }
};

gazeTracker.setUserStatusCallback(userStatusCallback);

---

ImageCallback

public interface ImageCallback extends GazeTrackerCallback

Front Camera Image buffer callback.

Summary

Functions
onImage

---

onImage

public void onImage(long timestamp, byte[] image)

Parameters	Type	Description
timestamp	long	Timestamp of the image in milliseconds. The time format is UTC
image	byte[]	byte[] of image. format is YUV(NV21), width = 640, height = 480

Example

@Override
public void onImage(long timestamp, byte[] image){
  try {
    File file = new File(yourJpgFilePath);
    FileOutputStream out = new FileOutputStream(file);
    YuvImage yuvImage = new YuvImage(image, ImageFormat.NV21, 640, 480, null);
    yuvImage.compressToJpeg(new Rect(0, 0, 640, 480), 50, out);
    out.flush();
    out.close();
  } catch (IOException e) {
    e.printStackTrace();
  }
}

---

InitializationErrorType

public enum InitializationErrorType

Contains error types of InitializationCallback.

See Authentication for more details.

---

StatusErrorType

public enum StatusErrorType

Contains error types of StatusCallback.

Name	Description
ERROR_NONE	Succeed without error
ERROR_CAMERA_START	GazeTracker.startTracking is called but the front camera of the device is not available
ERROR_CAMERA_INTERRUPT	The camera stream is disturbed(i.e. used by other applications) or the application running at the background

---

TrackingState

public enum TrackingState

Contains tracking state used at GazeInfo.

Name	Description
SUCCESS	Face alignment is in a best position (Gaze tracking success, with valid x and y)
LOW_CONFIDENCE	Face alignment is not in the best position, but can be used for tracking (Gaze tracking success, with less accurate x and y)
UNSUPPORTED	Face alignment is not suitable for tracking (Gaze tracking fail, with invalid x and y)
FACE_MISSING	Face is missing (Gaze tracking fail)

---

EyeMovementState

public enum EyeMovementState

Contains eye movement state used at GazeInfo.

Name	Description
FIXATION	Gazes from the past and the gazes up to the present have made a fixation
SACCADE	Gazes from the past and the gazes up to the present have formed a saccade
UNKNOWN	Not fixation or saccade

---

ScreenState

public enum ScreenState

Contains screen state used at GazeInfo.

Name	Description
INSIDE_OF_SCREEN	Gaze tracking succeeds and the gaze point is inside of the device screen
OUTSIDE_OF_SCREEN	Gaze tracking succeeds and the gaze point is outside of the device screen
UNKNOWN	Gaze tracking failed

---

CalibrationModeType

public enum CalibrationModeType

Contains calibration mode types of startCalibartion

Name	Description
DEFAULT	Set to the recommended mode. In the current version, Five-point calibration mode
ONE_POINT	One-point calibration mode
FIVE_POINT	Five-point calibration mode
SIX_POINT	Six-point calibration mode

---

AccuracyCriteria

public enum AccuracyCriteria

Contains accuracy criteria of startCalibartion.

Name	Description
DEFAULT	Default calibration accuracy criteria
LOW	Low calibration accuracy criteria
HIGH	High calibration accuracy criteria