tobii_research.ScreenBasedCalibration Class Reference

Provides methods and properties for managing calibrations for screen based eye trackers. More...

Inherits object.

Public Member Functions
def	__init__ (self, eyetracker)
	Initialize a new ScreenBasedCalibration object from an existing EyeTracker object.
def	enter_calibration_mode (self)
	Enters the calibration mode and the eye tracker is made ready for collecting data and calculating new calibrations. More...
def	leave_calibration_mode (self)
	Leaves the calibration mode. More...
def	collect_data (self, x, y)
	Starts collecting data for a calibration point. More...
def	discard_data (self, x, y)
	Removes the collected data associated with a specific calibration point. More...
def	compute_and_apply (self)
	Uses the data in the temporary buffer and tries to compute calibration parameters. More...

Detailed Description

Provides methods and properties for managing calibrations for screen based eye trackers.

Member Function Documentation

def tobii_research.ScreenBasedCalibration.collect_data	(		self,
			x,
			y
	)

Starts collecting data for a calibration point.

The argument used is the point the calibration user is assumed to be looking at and is given in the active display area coordinate system. See find_all_eyetrackers or EyeTracker.__init__ on how to create an EyeTracker object.

import time
import tobii_research as tr

calibration = tr.ScreenBasedCalibration(eyetracker)

# Enter calibration mode.
calibration.enter_calibration_mode()
print("Entered calibration mode for eye tracker with serial number {0}.".format(eyetracker.serial_number))

# Define the points on screen we should calibrate at.
# The coordinates are normalized, i.e. (0.0, 0.0) is the upper left corner and (1.0, 1.0) is the lower right corner.
points_to_calibrate = [(0.5, 0.5), (0.1, 0.1), (0.1, 0.9), (0.9, 0.1), (0.9, 0.9)]

for point in points_to_calibrate:
    print("Show a point on screen at {0}.".format(point))

    # Wait a little for user to focus.
    time.sleep(0.7)

    print("Collecting data at {0}.".format(point))
    if calibration.collect_data(point[0], point[1]) != tr.CALIBRATION_STATUS_SUCCESS:
        # Try again if it didn't go well the first time.
        # Not all eye tracker models will fail at this point, but instead fail on ComputeAndApply.
        calibration.collect_data(point[0], point[1])

print("Computing and applying calibration.")
calibration_result = calibration.compute_and_apply()
print("Compute and apply returned {0} and collected at {1} points.".
      format(calibration_result.status, len(calibration_result.calibration_points)))

# Analyze the data and maybe remove points that weren't good.
recalibrate_point = (0.1, 0.1)
print("Removing calibration point at {0}.".format(recalibrate_point))
calibration.discard_data(recalibrate_point[0], recalibrate_point[1])

# Redo collection at the discarded point
print("Show a point on screen at {0}.".format(recalibrate_point))
calibration.collect_data(recalibrate_point[0], recalibrate_point[1])

# Compute and apply again.
print("Computing and applying calibration.")
calibration_result = calibration.compute_and_apply()
print("Compute and apply returned {0} and collected at {1} points.".
      format(calibration_result.status, len(calibration_result.calibration_points)))

# See that you're happy with the result.

# The calibration is done. Leave calibration mode.
calibration.leave_calibration_mode()

print("Left calibration mode.")

Parameters

x	Normalized x coordinate on the active display area.
y	Normalized y coordinate on the active display area.

Exceptions

EyeTrackerConnectionFailedError
EyeTrackerFeatureNotSupportedError
EyeTrackerInvalidOperationError
EyeTrackerLicenseError
EyeTrackerInternalError

Returns

CALIBRATION_STATUS_SUCCESS on success. CALIBRATION_STATUS_FAILURE on failure.

def tobii_research.ScreenBasedCalibration.compute_and_apply

(

self

)

Uses the data in the temporary buffer and tries to compute calibration parameters.

If the call is successful, the data is copied from the temporary buffer to the active buffer. If there is insufficient data to compute a new calibration or if the collected data is not good enough then an exception will be raised. See find_all_eyetrackers or EyeTracker.__init__ on how to create an EyeTracker object.

import time
import tobii_research as tr

calibration = tr.ScreenBasedCalibration(eyetracker)

# Enter calibration mode.
calibration.enter_calibration_mode()
print("Entered calibration mode for eye tracker with serial number {0}.".format(eyetracker.serial_number))

# Define the points on screen we should calibrate at.
# The coordinates are normalized, i.e. (0.0, 0.0) is the upper left corner and (1.0, 1.0) is the lower right corner.
points_to_calibrate = [(0.5, 0.5), (0.1, 0.1), (0.1, 0.9), (0.9, 0.1), (0.9, 0.9)]

for point in points_to_calibrate:
    print("Show a point on screen at {0}.".format(point))

    # Wait a little for user to focus.
    time.sleep(0.7)

    print("Collecting data at {0}.".format(point))
    if calibration.collect_data(point[0], point[1]) != tr.CALIBRATION_STATUS_SUCCESS:
        # Try again if it didn't go well the first time.
        # Not all eye tracker models will fail at this point, but instead fail on ComputeAndApply.
        calibration.collect_data(point[0], point[1])

print("Computing and applying calibration.")
calibration_result = calibration.compute_and_apply()
print("Compute and apply returned {0} and collected at {1} points.".
      format(calibration_result.status, len(calibration_result.calibration_points)))

# Analyze the data and maybe remove points that weren't good.
recalibrate_point = (0.1, 0.1)
print("Removing calibration point at {0}.".format(recalibrate_point))
calibration.discard_data(recalibrate_point[0], recalibrate_point[1])

# Redo collection at the discarded point
print("Show a point on screen at {0}.".format(recalibrate_point))
calibration.collect_data(recalibrate_point[0], recalibrate_point[1])

# Compute and apply again.
print("Computing and applying calibration.")
calibration_result = calibration.compute_and_apply()
print("Compute and apply returned {0} and collected at {1} points.".
      format(calibration_result.status, len(calibration_result.calibration_points)))

# See that you're happy with the result.

# The calibration is done. Leave calibration mode.
calibration.leave_calibration_mode()

print("Left calibration mode.")

Exceptions

EyeTrackerConnectionFailedError
EyeTrackerFeatureNotSupportedError
EyeTrackerInvalidOperationError
EyeTrackerLicenseError
EyeTrackerInternalError

Returns

A CalibrationResult object.

def tobii_research.ScreenBasedCalibration.discard_data	(		self,
			x,
			y
	)

Removes the collected data associated with a specific calibration point.

See find_all_eyetrackers or EyeTracker.__init__ on how to create an EyeTracker object.

import time
import tobii_research as tr

calibration = tr.ScreenBasedCalibration(eyetracker)

# Enter calibration mode.
calibration.enter_calibration_mode()
print("Entered calibration mode for eye tracker with serial number {0}.".format(eyetracker.serial_number))

# Define the points on screen we should calibrate at.
# The coordinates are normalized, i.e. (0.0, 0.0) is the upper left corner and (1.0, 1.0) is the lower right corner.
points_to_calibrate = [(0.5, 0.5), (0.1, 0.1), (0.1, 0.9), (0.9, 0.1), (0.9, 0.9)]

for point in points_to_calibrate:
    print("Show a point on screen at {0}.".format(point))

    # Wait a little for user to focus.
    time.sleep(0.7)

    print("Collecting data at {0}.".format(point))
    if calibration.collect_data(point[0], point[1]) != tr.CALIBRATION_STATUS_SUCCESS:
        # Try again if it didn't go well the first time.
        # Not all eye tracker models will fail at this point, but instead fail on ComputeAndApply.
        calibration.collect_data(point[0], point[1])

print("Computing and applying calibration.")
calibration_result = calibration.compute_and_apply()
print("Compute and apply returned {0} and collected at {1} points.".
      format(calibration_result.status, len(calibration_result.calibration_points)))

# Analyze the data and maybe remove points that weren't good.
recalibrate_point = (0.1, 0.1)
print("Removing calibration point at {0}.".format(recalibrate_point))
calibration.discard_data(recalibrate_point[0], recalibrate_point[1])

# Redo collection at the discarded point
print("Show a point on screen at {0}.".format(recalibrate_point))
calibration.collect_data(recalibrate_point[0], recalibrate_point[1])

# Compute and apply again.
print("Computing and applying calibration.")
calibration_result = calibration.compute_and_apply()
print("Compute and apply returned {0} and collected at {1} points.".
      format(calibration_result.status, len(calibration_result.calibration_points)))

# See that you're happy with the result.

# The calibration is done. Leave calibration mode.
calibration.leave_calibration_mode()

print("Left calibration mode.")

Parameters

x	Normalized x coordinate on the active display area.
y	Normalized y coordinate on the active display area.

Exceptions

EyeTrackerConnectionFailedError
EyeTrackerFeatureNotSupportedError
EyeTrackerInvalidOperationError
EyeTrackerLicenseError
EyeTrackerInternalError

def tobii_research.ScreenBasedCalibration.enter_calibration_mode

(

self

)

Enters the calibration mode and the eye tracker is made ready for collecting data and calculating new calibrations.

See find_all_eyetrackers or EyeTracker.__init__ on how to create an EyeTracker object.

import time
import tobii_research as tr

calibration = tr.ScreenBasedCalibration(eyetracker)

# Enter calibration mode.
calibration.enter_calibration_mode()
print("Entered calibration mode for eye tracker with serial number {0}.".format(eyetracker.serial_number))

# Define the points on screen we should calibrate at.
# The coordinates are normalized, i.e. (0.0, 0.0) is the upper left corner and (1.0, 1.0) is the lower right corner.
points_to_calibrate = [(0.5, 0.5), (0.1, 0.1), (0.1, 0.9), (0.9, 0.1), (0.9, 0.9)]

for point in points_to_calibrate:
    print("Show a point on screen at {0}.".format(point))

    # Wait a little for user to focus.
    time.sleep(0.7)

    print("Collecting data at {0}.".format(point))
    if calibration.collect_data(point[0], point[1]) != tr.CALIBRATION_STATUS_SUCCESS:
        # Try again if it didn't go well the first time.
        # Not all eye tracker models will fail at this point, but instead fail on ComputeAndApply.
        calibration.collect_data(point[0], point[1])

print("Computing and applying calibration.")
calibration_result = calibration.compute_and_apply()
print("Compute and apply returned {0} and collected at {1} points.".
      format(calibration_result.status, len(calibration_result.calibration_points)))

# Analyze the data and maybe remove points that weren't good.
recalibrate_point = (0.1, 0.1)
print("Removing calibration point at {0}.".format(recalibrate_point))
calibration.discard_data(recalibrate_point[0], recalibrate_point[1])

# Redo collection at the discarded point
print("Show a point on screen at {0}.".format(recalibrate_point))
calibration.collect_data(recalibrate_point[0], recalibrate_point[1])

# Compute and apply again.
print("Computing and applying calibration.")
calibration_result = calibration.compute_and_apply()
print("Compute and apply returned {0} and collected at {1} points.".
      format(calibration_result.status, len(calibration_result.calibration_points)))

# See that you're happy with the result.

# The calibration is done. Leave calibration mode.
calibration.leave_calibration_mode()

print("Left calibration mode.")

Exceptions

EyeTrackerConnectionFailedError
EyeTrackerFeatureNotSupportedError
EyeTrackerInvalidOperationError
EyeTrackerLicenseError
EyeTrackerInternalError

def tobii_research.ScreenBasedCalibration.leave_calibration_mode

(

self

)

Leaves the calibration mode.

See find_all_eyetrackers or EyeTracker.__init__ on how to create an EyeTracker object.

import time
import tobii_research as tr

calibration = tr.ScreenBasedCalibration(eyetracker)

# Enter calibration mode.
calibration.enter_calibration_mode()
print("Entered calibration mode for eye tracker with serial number {0}.".format(eyetracker.serial_number))

# Define the points on screen we should calibrate at.
# The coordinates are normalized, i.e. (0.0, 0.0) is the upper left corner and (1.0, 1.0) is the lower right corner.
points_to_calibrate = [(0.5, 0.5), (0.1, 0.1), (0.1, 0.9), (0.9, 0.1), (0.9, 0.9)]

for point in points_to_calibrate:
    print("Show a point on screen at {0}.".format(point))

    # Wait a little for user to focus.
    time.sleep(0.7)

    print("Collecting data at {0}.".format(point))
    if calibration.collect_data(point[0], point[1]) != tr.CALIBRATION_STATUS_SUCCESS:
        # Try again if it didn't go well the first time.
        # Not all eye tracker models will fail at this point, but instead fail on ComputeAndApply.
        calibration.collect_data(point[0], point[1])

print("Computing and applying calibration.")
calibration_result = calibration.compute_and_apply()
print("Compute and apply returned {0} and collected at {1} points.".
      format(calibration_result.status, len(calibration_result.calibration_points)))

# Analyze the data and maybe remove points that weren't good.
recalibrate_point = (0.1, 0.1)
print("Removing calibration point at {0}.".format(recalibrate_point))
calibration.discard_data(recalibrate_point[0], recalibrate_point[1])

# Redo collection at the discarded point
print("Show a point on screen at {0}.".format(recalibrate_point))
calibration.collect_data(recalibrate_point[0], recalibrate_point[1])

# Compute and apply again.
print("Computing and applying calibration.")
calibration_result = calibration.compute_and_apply()
print("Compute and apply returned {0} and collected at {1} points.".
      format(calibration_result.status, len(calibration_result.calibration_points)))

# See that you're happy with the result.

# The calibration is done. Leave calibration mode.
calibration.leave_calibration_mode()

print("Left calibration mode.")

Exceptions

EyeTrackerConnectionFailedError
EyeTrackerFeatureNotSupportedError
EyeTrackerInvalidOperationError
EyeTrackerLicenseError
EyeTrackerInternalError