osi_featuredata.proto

syntax = "proto2";

option optimize_for = SPEED;

import "osi_version.proto";
import "osi_common.proto";

package osi3;

//
// \brief Interface for sensor data containing information without a history
// in contrast to interpreted data after object hypothesis and tracking.
//
// All information regarding the environment is given with respect to the sensor
// coordinate system specified in \c SensorDetectionHeader::mounting_position.
// When simulating multiple sensors, each sensor has an individual copy of
// \c FeatureData in its own reference frame. This allows an independent
// treatment of the sensors.
//
message FeatureData
{
    // The interface version used by the sender (i.e. the simulation
    // environment).
    //
    optional InterfaceVersion version = 1;

    // Radar detections for multiple radar sensors (sensor fusion).
    //
    repeated RadarDetectionData radar_sensor = 2;

    // Lidar detections for multiple lidar sensors (sensor fusion).
    //
    repeated LidarDetectionData lidar_sensor = 3;

    // Ultrasonic detections for multiple ultrasonic sensors (sensor fusion).
    //
    // \note Required for ultrasonic sensors: Detections will be send by the
    // emitting ultrasonic sensor, including all indirect detections received
    // by neighbouring sensors.
    //
    repeated UltrasonicDetectionData ultrasonic_sensor = 4;

    // Camera detections for multiple camera sensors (sensor fusion).
    //
    repeated CameraDetectionData camera_sensor = 5;
}

//
// \brief The header attributes of each sensor's detection list.
//
message SensorDetectionHeader
{
    // Time stamp at which the measurement was taken (not the time at which it
    // was processed or at which it is transmitted) in the global synchronized
    // time.
    //
    // \note See \c SensorData::timestamp and
    // \c SensorData::last_measurement_time for detailed discussions on the
    // semantics of time-related fields.
    //
    optional Timestamp measurement_time = 1;

    // Monotonous counter to identify the exact cycle.
    // In general the detection function is called periodically and
    // \c #cycle_counter corresponds to the number of periods.
    //
    // \rules
    // is_greater_than_or_equal_to: 0
    // \endrules
    //
    optional uint64 cycle_counter = 2;

    // Mounting position of the sensor (origin and orientation of the sensor
    // frame). Both origin and orientation are given in and with respect to the
    // host vehicle coordinate system (see: \c MovingObject::Vehicle vehicle
    // reference point) [1].
    //
    // The sensor frame's x-axis is pointing in the central viewing direction of
    // the sensor. It is the angle bisector of the sensor's horizontal and
    // vertical field of view. The terms horizontal and vertical must be
    // understood as names for the two principal planes of the sensor's field of
    // view (relative to the sensor frame's orientation), which do not have to
    // be horizontal or vertical in the strict sense of being parallel or
    // perpendicular to the local gravitational vector. The horizontal field
    // of view defines the sensor frame's xy-plane and the vertical field
    // of view defines the xz-plane. The sensor frame is right-handed and the
    // z-axis is pointing in an upward direction.
    //
    // The sensor frame uses cartesian coordinates. The sensor frame's origin is
    // identical to sensor detection frame's origin. Detections are defined in
    // the sensor detection frame which uses e.g. spherical coordinates.
    //
    // \par Reference:
    // [1] DIN Deutsches Institut fuer Normung e. V. (2013). <em>DIN ISO 8855 Strassenfahrzeuge - Fahrzeugdynamik und Fahrverhalten - Begriffe</em>. (DIN ISO 8855:2013-11). Berlin, Germany.
    //
    optional MountingPosition mounting_position = 3;

    // The origin/orientation of the sensor frame represents the current
    // mounting pose to the best knowledge of the sensor. The estimation of the
    // 6D pose given by the calibration. The uncertainty of this estimation is
    // given with the corresponding 6D root mean squared error. The estimation
    // of the current origin does not include effects due to short-time
    // dynamics, such as pitch angles from braking, but includes long-time
    // calibration values, such as pitch angles from luggage in the trunk.
    //
    optional MountingPosition mounting_position_rmse = 4;

    // Data Qualifier expresses to what extent the content of this event can be
    // relied on.
    //
    optional DataQualifier data_qualifier = 5;

    // The current number of valid detections in the detections list.
    //
    // \note This value has to be set if the list contains invalid detections.
    //
    // \rules
    // is_greater_than_or_equal_to: 0
    // \endrules
    //
    optional uint32 number_of_valid_detections = 6;

    // The ID of the sensor at host vehicle's \c #mounting_position.
    //
    // This ID can equal \c SensorData::sensor_id, if \c SensorData holds only
    // data from one sensor/sensor model.
    //
    optional Identifier sensor_id = 7;

    // The extended qualifier describes the reason (not the effect) why the
    // event data qualifier, \c #data_qualifier, is reduced or not available.
    //
    optional ExtendedQualifier extended_qualifier = 8;

    // Data qualifier communicates the overall availability of the
    // interface.
    //
    enum DataQualifier
    {
        // Unknown (must not be used in ground truth).
        //
        DATA_QUALIFIER_UNKNOWN = 0;

        // Other (unspecified but known).
        //
        DATA_QUALIFIER_OTHER = 1;

        // Data is available.
        //
        DATA_QUALIFIER_AVAILABLE = 2;

        // Reduced data is available.
        //
        DATA_QUALIFIER_AVAILABLE_REDUCED = 3;

        // Data is not available.
        //
        DATA_QUALIFIER_NOT_AVAILABLE = 4;

        // Sensor is blind.
        //
        DATA_QUALIFIER_BLINDNESS = 5;

        // Sensor temporary available.
        //
        DATA_QUALIFIER_TEMPORARY_AVAILABLE = 6;

        // Sensor invalid.
        //
        DATA_QUALIFIER_INVALID = 7;
    }

    // The extended qualifier describes the reason (not the effect) why the
    // event data qualifier, \c #data_qualifier, is reduced or not available.
    //
    enum ExtendedQualifier
    {
        // Unknown (must not be used in ground truth).
        //
        EXTENDED_QUALIFIER_UNKNOWN = 0;

        // Other (unspecified but known).
        //
        EXTENDED_QUALIFIER_OTHER = 1;

        // Normal operation mode.
        //
        EXTENDED_QUALIFIER_NORMAL_OPERATION_MODE = 2;

        // Power up or down.
        //
        EXTENDED_QUALIFIER_POWER_UP_OR_DOWN = 3;

        // Sensor not calibrated.
        //
        EXTENDED_QUALIFIER_SENSOR_NOT_CALIBRATED = 4;

        // Sensor blocked.
        //
        EXTENDED_QUALIFIER_SENSOR_BLOCKED = 5;

        // Sensor misaligned.
        //
        EXTENDED_QUALIFIER_SENSOR_MISALIGNED = 6;

        // Bad sensor environmental condition (e.g. Darkness for vision).
        //
        EXTENDED_QUALIFIER_BAD_SENSOR_ENVIRONMENTAL_CONDITION = 7;

        // Reduced field of view.
        //
        EXTENDED_QUALIFIER_REDUCED_FIELD_OF_VIEW = 8;

        // Input not available.
        //
        EXTENDED_QUALIFIER_INPUT_NOT_AVAILABLE = 9;

        // Internal reason (e.g. an internal HW or SW error has occurred).
        //
        EXTENDED_QUALIFIER_INTERNAL_REASON = 10;

        // External disturbance, sensor specific for front radar (e.g.
        // Interference of different radar sensors).
        //
        EXTENDED_QUALIFIER_EXTERNAL_DISTURBANCE = 11;

        // Beginning blockage, sensor specific for front radar.
        //
        EXTENDED_QUALIFIER_BEGINNING_BLOCKAGE = 12;
    }
}

//
// \brief Data from one radar sensor including a list of detections.
//
message RadarDetectionData
{
    // Header attributes of radar detection from one radar sensor.
    //
    optional SensorDetectionHeader header = 1;

    // List of radar detections constituting the radar detection list.
    //
    repeated RadarDetection detection = 2;
}

//
// \brief A radar detection.
//
message RadarDetection
{
    // Existence probability of the detection not based on history. Value does
    // not depend on any past experience with similar detections.
    //
    // \note Use as confidence measure where a low value means less confidence
    // and a high value indicates strong confidence.
    //
    // \rules
    // is_greater_than_or_equal_to: 0
    // is_less_than_or_equal_to: 1
    // \endrules
    //
    optional double existence_probability = 1;

    // ID of the detected object this detection is associated to.
    //
    // \note ID = MAX(uint64) indicates no reference to an object.
    //
    // \rules
    // refers_to: DetectedObject
    // \endrules
    //
    optional Identifier object_id = 2;

    // Measured position of the detection given in spherical coordinates in the
    // sensor coordinate system.
    //
    optional Spherical3d position = 3;

    // Root mean squared error of the measured position of the detection.
    //
    optional Spherical3d position_rmse = 4;

    // Radial velocity of the detection positive in direction to the sensor.
    //
    // Unit: m/s
    //
    optional double radial_velocity = 5;

    // Root mean squared error of the object measured radial velocity.
    //
    // Unit: m/s
    //
    // \rules
    // is_greater_than_or_equal_to: 0
    // \endrules
    //
    optional double radial_velocity_rmse = 6;

    // The radar cross section (RCS) of the radar detection.
    //
    // Unit: dB m^2
    //
    optional double rcs = 7;

    // The signal to noise ratio (SNR) of the radar detection.
    //
    // Unit: dB
    //
    optional double snr = 8;

    // Describes the possibility whether more than one object may have led to
    // this detection.
    //
    // \rules
    // is_greater_than_or_equal_to: 0
    // is_less_than_or_equal_to: 1
    // \endrules
    //
    optional double point_target_probability = 9;

    // Ambiguity Information:
    // Each ambiguous measurement generates one Ambiguity ID. Ambiguity is
    // indicated by an identical ambiguity ID.
    //
    // \note Unambiguous measurements have the ambiguity ID 0.
    //
    // \note Multiple seperate detections, from e.g. a large object, do not
    // necessarily on their own create any ambiguity. Therefore they do not
    // usually share an ambiguity ID. They can however be ambiguous
    // with other detections.
    //
    optional Identifier ambiguity_id = 10;

    // Basic classification of the detection.
    //
    optional DetectionClassification classification = 11;
}

//
// \brief Data from one lidar sensor including a list of detections.
//
message LidarDetectionData
{
    // Header attributes of lidar detection from one lidar sensor.
    //
    optional SensorDetectionHeader header = 1;

    // List of lidar detections.
    //
    repeated LidarDetection detection = 2;
}

//
// \brief A point or vertical line in a lidar point cloud.
//
message LidarDetection
{
    // Existence probability of the detection not based on history. Value does
    // not depend on any past experience with similar detections.
    //
    // \note Used as confidence measure where a low value means less confidence
    // and a high value indicates strong confidence.
    //
    // \rules
    // is_greater_than_or_equal_to: 0
    // is_less_than_or_equal_to: 1
    // \endrules
    //
    optional double existence_probability = 1;

    // ID of the detected object this detection is associated to.
    //
    // \note ID = MAX(uint64) indicates no reference to an object.
    //
    // \rules
    // refers_to: DetectedObject
    // \endrules
    //
    optional Identifier object_id = 2;

    // Measured position of the detection given in spherical coordinates in the
    // sensor coordinate system.
    //
    optional Spherical3d position = 3;

    // Root mean squared error of the measured position of the detection.
    //
    optional Spherical3d position_rmse = 4;

    // The height value which is required when multiple scan points are
    // vertically clustered. Only vertical clustering is allowed (z-axis).
    //
    // Unit: m
    //
    // \rules
    // is_greater_than_or_equal_to: 0
    // \endrules
    //
    optional double height = 5;

    // Root mean squared error of the object height.
    //
    // Unit: m
    //
    // \rules
    // is_greater_than_or_equal_to: 0
    // \endrules
    //
    optional double height_rmse = 6;

    // Intensity or equivalent value of the detection's echo.
    //
    // Unit: %
    //
    // \rules
    // is_greater_than_or_equal_to: 0
    // is_less_than_or_equal_to: 100
    // \endrules
    //
    optional double intensity = 7;

    // The free space probability in the range [0.0, 1.0] from the origin of the
    // sensor up to this detection, as given by the distance.
    //
    // \rules
    // is_greater_than_or_equal_to: 0
    // is_less_than_or_equal_to: 1
    // \endrules
    //
    optional double free_space_probability = 8;

    // Basic classification of the detection.
    //
    optional DetectionClassification classification = 9;

    // Lambertian reflectivity.
    //
    optional double reflectivity = 10;

    // Echo pulse width of the detection's echo.
    // Several sensors output an echo pulse width instead of an intensity for each individual detection.
    // The echo pulse is measured in m and measures the extent of the object parts or atmospheric particles that produce the echo.
    // \note For more details see [1] Fig. 7 and 8.
    // \note Fig. 7 shows an example where the two echos are reflected from the edges A-B and C-D.
    // \note Fig. 8 shows how the echo pulse width is measured as the range between the rising edge and the falling edge that crosses the intensity threshold.
    //
    // Unit: m
    //
    // \rules
    // is_greater_than_or_equal_to: 0
    // \endrules
    //
    // \par Reference:
    // [1] Rosenberger, P., Holder, M.F., Cianciaruso, N. et al. (2020). <em>Sequential lidar sensor system simulation: a modular approach for simulation-based safety validation of automated driving</em> Automot. Engine Technol. 5, Fig 7, Fig 8. Retrieved May 10, 2021, from https://doi.org/10.1007/s41104-020-00066-x
    //
    optional double echo_pulse_width = 11;
}

//
// \brief Specific header extension for ultrasonic sensors.
//
message UltrasonicDetectionSpecificHeader
{
    // Maximal range of the ultrasonic sensor.
    //
    // Unit: m
    //
    optional double max_range = 1;

    // The current number of valid indirect detections in the detections list.
    // The detections are measured by a virtual sensor (i.e. sender and
    // receiver are different sensors).
    //
    // \note This value has to be set if the list contains invalid detections.
    //
    optional uint32 number_of_valid_indirect_detections = 2;
}

//
// \brief Data from one ultrasonic sensor including a list of detections.
// This list is generated by the sending ultrasonic sensor. Indirectly received
// signals from other ultrasonic sensors are included in this message.
//
// Direct detections:
//
// Sending: Ultrasonic Sensor ID 1
//
// Receiving:
// - Direct: Ultrasonic Sensor ID 1
// - Indirect: Ultrasonic Sensor ID 2 and 3
//
// \image html OSI_USSensor.svg
//
// \note Direct detecions lies on circles with the sending sensor as centre.
//
message UltrasonicDetectionData
{
    // Header attributes of ultrasonic detection from one ultrasonic sensor.
    //
    optional SensorDetectionHeader header = 1;

    // Additional header attributes of ultrasonic detection from one ultrasonic
    // sensor.
    //
    optional UltrasonicDetectionSpecificHeader specific_header = 3;

    // List of ultrasonic detections.
    //
    repeated UltrasonicDetection detection = 2;

    // List of ultrasonic indirect detections (sender and receiver sensors are
    // not the same).
    //
    repeated UltrasonicIndirectDetection indirect_detection = 4;
}

//
// \brief Ultrasonic detection from the sensor (same sensor as sender and
// receiver).
//
// Direct detections:
//
// Sending: Ultrasonic Sensor ID 1
//
// Receiving: Ultrasonic Sensor ID 1
//
// \image html OSI_USSensor_direct.svg
//
// \note Direct detecions lies on circles with the sensor as centre.
//
message UltrasonicDetection
{
    // Existence probability of the detection not based on history. Value does
    // not depend on any past experience with similar detections.
    //
    // \note Used as confidence measure where a low value means less confidence
    // and a high value indicates strong confidence.
    //
    // \rules
    // is_greater_than_or_equal_to: 0
    // is_less_than_or_equal_to: 1
    // \endrules
    //
    optional double existence_probability = 1;

    // ID of the detected object this detection is associated to.
    //
    // \note ID = MAX(uint64) indicates no reference to an object.
    //
    // \rules
    // refers_to: DetectedObject
    // \endrules
    //
    optional Identifier object_id = 2;

    // Measured distance (radius) of the detection.
    //
    // Unit: m
    //
    // \rules
    // is_greater_than_or_equal_to: 0
    // \endrules
    //
    optional double distance = 3;
}

//
// \brief Ultrasonic detection received by another ultrasonic sensor (different
// sensors as sender and receiver).
//
// Indirect detections:
//
// Sending: Ultrasonic Sensor ID 1
//
// Receiving: Ultrasonic Sensor ID 2 and 3
//
// \image html OSI_USSensor_indirect.svg
//
// \note Indirect detecions lies on ellipses with the sending resp. receiving
// sensor in the focal points.
//
message UltrasonicIndirectDetection
{
    // Existence probability of the detection not based on history. Value does
    // not depend on any past experience with similar detections.
    //
    // \note Used as confidence measure where a low value means less confidence
    // and a high value indicates strong confidence.
    //
    // \rules
    // is_greater_than_or_equal_to: 0
    // is_less_than_or_equal_to: 1
    // \endrules
    //
    optional double existence_probability = 1;

    // ID of the detected object this detection is associated to.
    //
    // \note ID = MAX(uint64) indicates no reference to an object.
    //
    // \rules
    // refers_to: DetectedObject
    // \endrules
    //
    optional Identifier object_id = 2;

    // First parameter b of an ellipsoid equation.
    //
    // Unit: m
    //
    optional double ellipsoid_radial = 3;

    // Second parameter b of an ellipsoid equation.
    //
    // Unit: m
    //
    optional double ellipsoid_axial = 4;

    // The ID of the sensor's receiver. Sender ID is stored in the header \c
    // SensorDetectionHeader.
    //
    optional Identifier receiver_id = 5;

    // The vector to the receiver's origin in sending ultrasonic sensor frame.
    // The vector is also the direction of \c #ellipsoid_axial.
    //
    optional Vector3d receiver_origin = 6;
}

//
// \brief Specific header extension for camera sensors.
//
message CameraDetectionSpecificHeader
{
    // The current number of points which all detections in the detections list
    // refer.
    //
    // \note This value has to be set if the list contains invalid points.
    //
    // \rules
    // is_greater_than_or_equal_to: 0
    // \endrules
    //
    optional uint32 number_of_valid_points = 1;
}

//
// \brief Data from one camera sensor including a list of detections.
//
message CameraDetectionData
{
    // Header attributes of camera detection from one camera sensor.
    //
    optional SensorDetectionHeader header = 1;

    // Additional header attributes of camera detection from one camera sensor.
    //
    optional CameraDetectionSpecificHeader specific_header = 3;

    // List of camera detections.
    //
    repeated CameraDetection detection = 2;

    // List of points which are used by detections.
    //
    repeated CameraPoint point = 4;
}

//
// \brief Camera detection from the sensor.
//
message CameraDetection
{
    // Existence probability of the detection not based on history. Value does
    // not depend on any past experience with similar detections.
    //
    // \note Used as confidence measure where a low value means less confidence
    // and a high value indicates strong confidence.
    //
    // \rules
    // is_greater_than_or_equal_to: 0
    // is_less_than_or_equal_to: 1
    // \endrules
    //
    optional double existence_probability = 1;

    // ID of the detected object this detection is associated to.
    //
    // \note ID = MAX(uint64) indicates no reference to an object.
    //
    // \rules
    // refers_to: DetectedObject
    // \endrules
    //
    optional Identifier object_id = 2;

    // Difference to the base timestamp \c
    // SensorDetectionHeader::measurement_time.
    //
    // The timestamp of this detection :=
    // \c SensorDetectionHeader::measurement_time + \c #time_difference.
    //
    optional Timestamp time_difference = 3;

    // Definition of the image shape type of this detection.
    //
    optional ImageShapeType image_shape_type = 4;

    // The defined shape is background.
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_background = 5;

    // The defined shape is foregroud.
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_foreground = 6;

    // The defined shape is flat.
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_flat = 7;

    // The defined shape is upright.
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_upright = 8;

    // The defined shape is ground.
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_ground = 9;

    // The defined shape is sky.
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_sky = 10;

    // The defined shape is vegetation.
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_vegetation = 11;

    // The defined shape is a road.
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_road = 12;

    // The defined shape is a non-driving lane (e.g. sidewalk).
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_non_driving_lane = 13;

    // The defined shape is non-road (e.g. traffic island).
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_non_road = 14;

    // The defined shape is a stationary object.
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_stationary_object = 15;

    // The defined shape is a possible moving object.
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_moving_object = 16;

    // The defined shape is a landmark.
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_landmark = 17;

    // The defined shape is a traffic sign.
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_traffic_sign = 18;

    // The defined shape is a traffic light.
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_traffic_light = 19;

    // The defined shape is a road marking sign.
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_road_marking = 20;

    // The defined shape is a vehicle.
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_vehicle = 21;

    // The defined shape is a pedestrian.
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_pedestrian = 22;

    // The defined shape is an animal.
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_animal = 23;

    // The defined shape is a pedestrian seen by the sensor from the front.
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_pedestrian_front = 24;

    // The defined shape is a pedestrian seen by the sensor from the side.
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_pedestrian_side = 25;

    // The defined shape is a pedestrian seen by the sensor from the rear.
    // The probability for this classification is at least
    // \c #shape_classification_probability.
    //
    optional bool shape_classification_pedestrian_rear = 26;

    // This probability defines the mininimum probability for each selected
    // shape classification.
    //
    // \rules
    // is_greater_than_or_equal_to: 0
    // is_less_than_or_equal_to: 1
    // \endrules
    //
    optional double shape_classification_probability = 27;

    // The dominant color of the shape.
    //
    // \attention DEPRECATED: This color enum will be removed in version
    // 4.0.0. Use the field \c #color_description (\c ColorDescription)
    // instead.
    //
    optional Color color = 28;

    // The probability of the shape's color.
    //
    // \rules
    // is_greater_than_or_equal_to: 0
    // is_less_than_or_equal_to: 1
    // \endrules
    //
    optional double color_probability = 29;

    // If one shape has different shape classifications and shape classification
    // probability or color and color probability, all detections in this cycle
    // have the same ambiguity ID.
    //
    // \note ID = MAX(uint64) indicates no reference to an object.
    //
    optional Identifier ambiguity_id = 30;

    // Index of the first point in the camera detection.
    //
    optional uint32 first_point_index = 31;

    // Number of points which defines the shape.
    // \c #image_shape_type may restrict the number of possible values.
    //
    // \rules
    // is_greater_than_or_equal_to: 0
    // \endrules
    //
    optional uint32 number_of_points = 32;

    //
    // The dominant color of the shape.
    //
    optional ColorDescription color_description = 33;

    // Definition of shape dominant color.
    //
    // \attention DEPRECATED: This color enum will be removed in version
    // 4.0.0. Use \c ColorDescription instead.
    //
    enum Color
    {
        // Color of the shape is unknown (must not be used in ground
        // truth).
        //
        COLOR_UNKNOWN = 0;

        // Shape with another (unspecified but known) color.
        //
        COLOR_OTHER = 1;

        // Shape with black color.
        //
        COLOR_BLACK = 2;

        // Shape with grey color.
        //
        COLOR_GREY = 3;

        // Shape with white color.
        //
        COLOR_WHITE = 4;

        // Shape with yellow color.
        //
        COLOR_YELLOW = 5;

        // Shape with orange color.
        //
        COLOR_ORANGE = 6;

        // Shape with red color.
        //
        COLOR_RED = 7;

        // Shape with violet color.
        //
        COLOR_VIOLET = 8;

        // Shape with blue color.
        //
        COLOR_BLUE = 9;

        // Shape with green color.
        //
        COLOR_GREEN = 10;

        // Shape with reflective color.
        //
        COLOR_REFLECTIVE = 11;
    }

    // Definition of different image shape types.
    //
    enum ImageShapeType
    {
        // Shape type is unknown (must not be used in ground truth).
        //
        IMAGE_SHAPE_TYPE_UNKNOWN = 0;

        // Other (unspecified but known) shape type.
        //
        IMAGE_SHAPE_TYPE_OTHER = 1;

        // Image shape is defined by a single point.
        //
        // Allowed number of referenced points: 1
        //
        IMAGE_SHAPE_TYPE_POINT = 2;

        // Image shape is defined by a box.
        //
        // Allowed number of referenced points: 2 or 3
        //
        // Allowed number of referenced points = 2: first and third corner of
        // the box. Box is alligned horizontal resp. vertical.
        //
        // Allowed number of referenced points = 3: first, second and third
        // corner of the box. fourth corner is calculated by first+third-second
        // corner.
        //
        IMAGE_SHAPE_TYPE_BOX = 3;

        // Image shape is defined by an ellipse.
        //
        // Allowed number of referenced points: 2 or 3
        //
        // Allowed number of referenced points = 2: center point of circle,
        // point on circle
        //
        // Allowed number of referenced points = 3: center point of ellipse,
        // point on ellipse at main axis of ellipse, point on ellipse at minor
        // axis of ellipse
        //
        IMAGE_SHAPE_TYPE_ELLIPSE = 4;

        // Image shape is defined by a polygon.
        //
        // Allowed number of referenced points: 3 .. n
        //
        // Polygon is defined by the first, second, third and so on points. The
        // polygon shape is closed (last and first point are different).
        //
        IMAGE_SHAPE_TYPE_POLYGON = 5;

        // Image shape is defined by a polyline.
        //
        // Allowed number of referenced points: 2 .. n
        //
        // Polyline is defined by the first, second and so on points. The
        // polyline shape is open.
        //
        IMAGE_SHAPE_TYPE_POLYLINE = 6;

        // Image shape is defined by a point cloud.
        //
        // Allowed number of referenced points: 2 .. n
        //
        // Point cloud is defined by a number of points. The points are not
        // connected in the point cloud.
        //
        IMAGE_SHAPE_TYPE_POINT_CLOUD = 7;
    }
}

//
// \brief Camera point from the sensor.
//
message CameraPoint
{
    // Existence probability of the point not based on history. Value does
    // not depend on any past experience with similar points.
    //
    // \note Used as confidence measure where a low value means less confidence
    // and a high value indicates strong confidence.
    //
    // \rules
    // is_greater_than_or_equal_to: 0
    // is_less_than_or_equal_to: 1
    // \endrules
    //
    optional double existence_probability = 1;

    // Measured point refered by one camera detection given in spherical
    // coordinates in the sensor coordinate system.
    //
    optional Spherical3d point = 2;

    // Root mean squared error of the measured point.
    //
    optional Spherical3d point_rmse = 3;
}

// Definition of a basic detection classifications.
//
enum DetectionClassification
{
    // Detection is unknown (must not be used in ground truth).
    //
    DETECTION_CLASSIFICATION_UNKNOWN = 0;

    // Other (unspecified but known) detection.
    //
    DETECTION_CLASSIFICATION_OTHER = 1;

    // Invalid detection, not to be used for object tracking, of unspecified
    // type (none of the other types applies).
    //
    DETECTION_CLASSIFICATION_INVALID = 2;

    // Clutter (noise, spray, rain, fog etc.).
    //
    DETECTION_CLASSIFICATION_CLUTTER = 3;

    // Over-drivable (ground etc.).
    //
    DETECTION_CLASSIFICATION_OVERDRIVABLE = 4;

    // Under-drivable (sign gantry etc.).
    //
    DETECTION_CLASSIFICATION_UNDERDRIVABLE = 5;
}