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#!/usr/bin/env python
""" """
__author__ = "Théo de la Hogue"
__credits__ = []
__copyright__ = "Copyright 2023, Ecole Nationale de l'Aviation Civile (ENAC)"
__license__ = "BSD"
from typing import TypeVar, Tuple
from dataclasses import dataclass, field
import json
import math
import itertools
import re
from argaze import DataFeatures
from argaze.ArUcoMarkers import ArUcoMarkersDictionary, ArUcoMarker, ArUcoOpticCalibrator
import numpy
import cv2
T0 = numpy.array([0., 0., 0.])
"""Define no translation vector."""
R0 = numpy.array([[1., 0., 0.], [0., 1., 0.], [0., 0., 1.]])
"""Define no rotation matrix."""
ArUcoMarkersGroupType = TypeVar('ArUcoMarkersGroup', bound="ArUcoMarkersGroup")
# Type definition for type annotation convenience
def make_rotation_matrix(x, y, z):
# Create rotation matrix around x axis
c = numpy.cos(numpy.deg2rad(x))
s = numpy.sin(numpy.deg2rad(x))
Rx = numpy.array([[1, 0, 0], [0, c, -s], [0, s, c]])
# Create rotation matrix around y axis
c = numpy.cos(numpy.deg2rad(y))
s = numpy.sin(numpy.deg2rad(y))
Ry = numpy.array([[c, 0, s], [0, 1, 0], [-s, 0, c]])
# Create rotation matrix around z axis
c = numpy.cos(numpy.deg2rad(z))
s = numpy.sin(numpy.deg2rad(z))
Rz = numpy.array([[c, -s, 0], [s, c, 0], [0, 0, 1]])
# Return intrinsic rotation matrix
return Rx.dot(Ry.dot(Rz))
def is_rotation_matrix(R):
Rt = numpy.transpose(R)
shouldBeIdentity = numpy.dot(Rt, R)
I = numpy.identity(3, dtype = R.dtype)
n = numpy.linalg.norm(I - shouldBeIdentity)
return n < 1e-3
@dataclass(frozen=True)
class Place():
"""Define a place as list of corners position and a marker.
Parameters:
corners: 3D corners position in group referential.
marker: ArUco marker linked to the place.
"""
corners: numpy.array
marker: dict
@dataclass
class ArUcoMarkersGroup(DataFeatures.PipelineStepObject):
"""
Handle group of ArUco markers as one unique spatial entity and estimate its pose.
"""
def __init__(self, dictionary: ArUcoMarkersDictionary.ArUcoMarkersDictionary = None, places: dict = None, **kwargs):
"""Initialize ArUcoMarkersGroup
Parameters:
dictionary: expected dictionary of all markers in the group.
places: expected markers place.
"""
# Init parent classes
DataFeatures.PipelineStepObject.__init__(self, **kwargs)
# Init private attributes
self.__dictionary = dictionary
self.__places = places
self.__translation = numpy.zeros(3)
self.__rotation = numpy.zeros(3)
# Normalize places data
new_places = {}
for identifier, data in self.__places.items():
# Convert string identifier to int value
if type(identifier) == str:
identifier = int(identifier)
# Get translation vector
tvec = numpy.array(data.pop('translation')).astype(numpy.float32)
# Check rotation value shape
rvalue = numpy.array(data.pop('rotation')).astype(numpy.float32)
# Rotation matrix
if rvalue.shape == (3, 3):
rmat = rvalue
# Rotation vector (expected in degree)
elif rvalue.shape == (3,):
rmat = make_rotation_matrix(rvalue[0], rvalue[1], rvalue[2]).astype(numpy.float32)
else:
raise ValueError(f'Bad rotation value: {rvalue}')
assert(is_rotation_matrix(rmat))
# Get marker size
size = numpy.array(data.pop('size')).astype(numpy.float32)
new_marker = ArUcoMarker.ArUcoMarker(self.__dictionary, identifier, size)
# Build marker corners thanks to translation vector and rotation matrix
place_corners = numpy.array([[-size/2, size/2, 0], [size/2, size/2, 0], [size/2, -size/2, 0], [-size/2, -size/2, 0]])
place_corners = place_corners.dot(rmat) + tvec
new_places[identifier] = Place(place_corners, new_marker)
# else places are configured using detected markers estimated points
elif isinstance(data, ArUcoMarker.ArUcoMarker):
new_places[identifier] = Place(data.points, data)
# else places are already at expected format
elif (type(identifier) == int) and isinstance(data, Place):
new_places[identifier] = data
self.__places = new_places
@property
def dictionary(self) -> ArUcoMarkersDictionary.ArUcoMarkersDictionary:
"""Get ArUco marker group ArUco dictionary."""
return self.__dictionary
@property
def places(self) -> dict:
"""Get ArUco marker group places dictionary."""
return self.__places
@property
def identifiers(self) -> list:
"""List place marker identifiers belonging to the group."""
return list(self.__places.keys())
@property
def translation(self) -> numpy.array:
"""Get ArUco marker group translation vector."""
return self.__translation
@translation.setter
def translation(self, tvec):
"""Set ArUco marker group translation vector."""
self.__translation = tvec
@property
def rotation(self) -> numpy.array:
"""Get ArUco marker group rotation matrix."""
return self.__translation
@rotation.setter
def rotation(self, rmat):
"""Set ArUco marker group rotation matrix."""
self.__rotation = rmat
def as_dict(self) -> dict:
"""Export ArUco marker group properties as dictionary."""
return {
**DataFeatures.PipelineStepObject.as_dict(self),
"dictionary": self.__dictionary,
"places": self.__places
}
@classmethod
def from_dict(cls, aruco_markers_group_data: dict, working_directory: str = None) -> ArUcoMarkersGroupType:
"""Load ArUco markers group attributes from dictionary.
Parameters:
aruco_markers_group_data: dictionary with attributes to load
working_directory: folder path where to load files when a dictionary value is a relative filepath.
"""
new_dictionary = aruco_markers_group_data.pop('dictionary')
new_places = aruco_markers_group_data.pop('places')
return ArUcoMarkersGroup(new_dictionary, new_places)
@classmethod
def from_obj(self, obj_filepath: str) -> ArUcoMarkersGroupType:
"""Load ArUco markers group from .obj file.
!!! note
Expected object (o) name format: <DICTIONARY>#<IDENTIFIER>_Marker
!!! note
All markers have to belong to the same dictionary.
"""
new_dictionary = None
new_places = {}
# Regex rules for .obj file parsing
OBJ_RX_DICT = {
'object': re.compile(r'o (.*)#([0-9]+)_(.*)\n'),
'vertice': re.compile(r'v ([+-]?[0-9]*[.]?[0-9]+) ([+-]?[0-9]*[.]?[0-9]+) ([+-]?[0-9]*[.]?[0-9]+)\n'),
'face': re.compile(r'f ([0-9]+) ([0-9]+) ([0-9]+) ([0-9]+)\n'),
'comment': re.compile(r'#(.*)\n') # keep comment regex after object regex because the # is used in object string too
}
# Regex .obj line parser
def __parse_obj_line(line):
for key, rx in OBJ_RX_DICT.items():
match = rx.search(line)
if match:
return key, match
# If there are no matches
return None, None
# Start parsing
try:
identifier = None
vertices = []
faces = {}
# Open the file and read through it line by line
with open(obj_filepath, 'r') as file:
line = file.readline()
while line:
# At each line check for a match with a regex
key, match = __parse_obj_line(line)
# Extract comment
if key == 'comment':
pass
# Extract marker dictionary and identifier
elif key == 'object':
dictionary = str(match.group(1))
identifier = int(match.group(2))
last = str(match.group(3))
# Init new group dictionary with first dictionary name
if new_dictionary == None:
new_dictionary = ArUcoMarkersDictionary.ArUcoMarkersDictionary(dictionary)
# Check all others marker dictionary are equal to new group dictionary
elif dictionary != new_dictionary.name:
raise NameError(f'Marker {identifier} dictionary is not {new_dictionary.name}')
# Fill vertices array
elif key == 'vertice':
vertices.append(tuple([float(match.group(1)), float(match.group(2)), float(match.group(3))]))
# Extract vertice ids
elif key == 'face':
faces[identifier] = [int(match.group(1)), int(match.group(2)), int(match.group(3)), int(match.group(4))]
# Go to next line
line = file.readline()
file.close()
# Retreive marker vertices thanks to face vertice ids
for identifier, face in faces.items():
# Gather place corners in clockwise order
cw_corners = numpy.array([ vertices[i-1] for i in reversed(face) ])
# Edit place axis from corners positions
place_x_axis = cw_corners[2] - cw_corners[3]
place_x_axis_norm = numpy.linalg.norm(place_x_axis)
place_y_axis = cw_corners[0] - cw_corners[3]
place_y_axis_norm = numpy.linalg.norm(place_y_axis)
# Check axis size: they should be almost equal
if math.isclose(place_x_axis_norm, place_y_axis_norm, rel_tol=1e-3):
new_marker_size = place_x_axis_norm
else:
raise ValueError(f'{new_dictionary}#{identifier}_Marker is not a square.')
# Create a new place related to a new marker
new_marker = ArUcoMarker.ArUcoMarker(new_dictionary, identifier, new_marker_size)
new_places[identifier] = Place(cw_corners, new_marker)
except IOError:
raise IOError(f'File not found: {obj_filepath}')
return ArUcoMarkersGroup(new_dictionary, new_places)
def filter_markers(self, detected_markers: dict) -> Tuple[dict, dict]:
"""Sort markers belonging to the group from given detected markers dict (cf ArUcoDetector.detect_markers()).
Returns:
dict of markers belonging to this group
dict of remaining markers not belonging to this group
"""
group_markers = {}
remaining_markers = {}
for (marker_id, marker) in detected_markers.items():
if marker_id in self.__places.keys():
group_markers[marker_id] = marker
else:
remaining_markers[marker_id] = marker
return group_markers, remaining_markers
def estimate_pose_from_markers_corners(self, markers: dict, K: numpy.array, D: numpy.array) -> Tuple[bool, numpy.array, numpy.array]:
"""Estimate pose from markers corners and places corners.
Parameters:
markers: detected markers to use for pose estimation.
K: intrinsic camera parameters
D: camera distorsion matrix
Returns:
success: True if the pose estimation succeeded
tvec: scene translation vector
rvec: scene rotation vector
"""
markers_corners_2d = []
places_corners_3d = []
for identifier, marker in markers.items():
try:
place = self.__places[identifier]
for marker_corner in marker.corners:
markers_corners_2d.append(list(marker_corner))
for place_corner in place.corners:
places_corners_3d.append(list(place_corner))
except KeyError:
raise ValueError(f'Marker {marker.identifier} doesn\'t belong to the group.')
# SolvPnP using cv2.SOLVEPNP_SQPNP flag
# TODO: it works also with cv2.SOLVEPNP_EPNP flag so we need to test which is the faster.
# About SolvPnP flags: https://docs.opencv.org/4.x/d5/d1f/calib3d_solvePnP.html
success, rvec, tvec = cv2.solvePnP(numpy.array(places_corners_3d), numpy.array(markers_corners_2d), numpy.array(K), numpy.array(D), flags=cv2.SOLVEPNP_SQPNP)
# Refine pose estimation using Gauss-Newton optimisation
if success :
rvec, tvec = cv2.solvePnPRefineVVS(numpy.array(places_corners_3d), numpy.array(markers_corners_2d), numpy.array(K), numpy.array(D), rvec, tvec)
self.__translation = tvec.T
self.__rotation = rvec.T
return success, self.__translation, self.__rotation
def draw_axes(self, image: numpy.array, K, D, thickness: int = 0, length: float = 0):
"""Draw group axes."""
try:
axisPoints = numpy.float32([[length, 0, 0], [0, length, 0], [0, 0, length], [0, 0, 0]]).reshape(-1, 3)
axisPoints, _ = cv2.projectPoints(axisPoints, self.__rotation, self.__translation, numpy.array(K), numpy.array(D))
axisPoints = axisPoints.astype(int)
cv2.line(image, tuple(axisPoints[3].ravel()), tuple(axisPoints[0].ravel()), (0, 0, 255), thickness) # X (red)
cv2.line(image, tuple(axisPoints[3].ravel()), tuple(axisPoints[1].ravel()), (0, 255, 0), thickness) # Y (green)
cv2.line(image, tuple(axisPoints[3].ravel()), tuple(axisPoints[2].ravel()), (255, 0, 0), thickness) # Z (blue)
# Ignore errors due to out of field axis: their coordinate are larger than int32 limitations.
except cv2.error:
pass
def draw_places(self, image: numpy.array, K, D, color: tuple = None, border_size: int = 0):
"""Draw group places."""
l = self.marker_size / 2
for identifier, place in self.__places.items():
try:
placePoints, _ = cv2.projectPoints(place.corners, self.__rotation, self.__translation, numpy.array(K), numpy.array(D))
placePoints = placePoints.astype(int)
cv2.line(image, tuple(placePoints[0].ravel()), tuple(placePoints[1].ravel()), color, border_size)
cv2.line(image, tuple(placePoints[1].ravel()), tuple(placePoints[2].ravel()), color, border_size)
cv2.line(image, tuple(placePoints[2].ravel()), tuple(placePoints[3].ravel()), color, border_size)
cv2.line(image, tuple(placePoints[3].ravel()), tuple(placePoints[0].ravel()), color, border_size)
# Ignore errors due to out of field places: their coordinate are larger than int32 limitations.
except cv2.error:
pass
def draw(self, image: numpy.array, K, D, draw_axes: dict = None, draw_places: dict = None):
"""Draw group axes and places.
Parameters:
draw_axes: draw_axes parameters (if None, no axes drawn)
draw_places: draw_places parameters (if None, no places drawn)
"""
# Draw axes if required
if draw_axes is not None:
self.draw_axes(image, K, D, **draw_axes)
# Draw places if required
if draw_places is not None:
self.draw_places(image, K, D, **draw_places)
def to_obj(self, obj_filepath):
"""Save group to .obj file."""
with open(obj_filepath, 'w', encoding='utf-8') as file:
file.write('# ArGaze OBJ File\n')
file.write('# http://achil.recherche.enac.fr/features/eye/argaze/\n')
v_count = 0
for p, (identifier, place) in enumerate(self.__places.items()):
file.write(f'o {self.__dictionary.name}#{identifier}_Marker\n')
vertices = ''
# Write vertices in reverse order
for v in [3, 2, 1, 0]:
file.write(f'v {" ".join(map(str, place.corners[v]))}\n')
v_count += 1
vertices += f' {v_count}'
#file.write('s off\n')
file.write(f'f{vertices}\n')
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