pose2sim/Pose2Sim/Utilities/calib_toml_to_opencap.py
2024-07-10 10:12:57 +02:00

183 lines
6.2 KiB
Python

#!/usr/bin/env python
# -*- coding: utf-8 -*-
'''
##################################################
## TOML CALIBRATION TO OPENCAP CALIBRATION ##
##################################################
Convert an OpenCV .toml calibration file
to OpenCap .pickle calibration files.
One file will be created for each camera.
Usage:
from Pose2Sim.Utilities import calib_toml_to_opencap; calib_toml_to_opencap.calib_toml_to_opencap_func(r'<input_toml_file>')
OR python -m calib_toml_to_opencap -t input_toml_file
OR python -m calib_toml_to_opencap -t input_toml_file -o output_calibration_folder>
'''
## INIT
import os
import pickle
import argparse
import numpy as np
import toml
import cv2
## AUTHORSHIP INFORMATION
__author__ = "David Pagnon"
__copyright__ = "Copyright 2021, Pose2Sim"
__credits__ = ["David Pagnon"]
__license__ = "BSD 3-Clause License"
__version__ = "0.9.4"
__maintainer__ = "David Pagnon"
__email__ = "contact@david-pagnon.com"
__status__ = "Development"
## FUNCTIONS
def world_to_camera_persp(r, t):
'''
Converts rotation R and translation T
from Qualisys object centered perspective
to OpenCV camera centered perspective
and inversely.
Qc = RQ+T --> Q = R-1.Qc - R-1.T
'''
r = r.T
t = - r @ t
return r, t
def rotate_cam(r, t, ang_x=0, ang_y=0, ang_z=0):
'''
Apply rotations around x, y, z in cameras coordinates
Angle in radians
'''
r,t = np.array(r), np.array(t)
if r.shape == (3,3):
rt_h = np.block([[r,t.reshape(3,1)], [np.zeros(3), 1 ]])
elif r.shape == (3,):
rt_h = np.block([[cv2.Rodrigues(r)[0],t.reshape(3,1)], [np.zeros(3), 1 ]])
r_ax_x = np.array([1,0,0, 0,np.cos(ang_x),-np.sin(ang_x), 0,np.sin(ang_x),np.cos(ang_x)]).reshape(3,3)
r_ax_y = np.array([np.cos(ang_y),0,np.sin(ang_y), 0,1,0, -np.sin(ang_y),0,np.cos(ang_y)]).reshape(3,3)
r_ax_z = np.array([np.cos(ang_z),-np.sin(ang_z),0, np.sin(ang_z),np.cos(ang_z),0, 0,0,1]).reshape(3,3)
r_ax = r_ax_z @ r_ax_y @ r_ax_x
r_ax_h = np.block([[r_ax,np.zeros(3).reshape(3,1)], [np.zeros(3), 1]])
r_ax_h__rt_h = r_ax_h @ rt_h
r = r_ax_h__rt_h[:3,:3]
t = r_ax_h__rt_h[:3,3]
return r, t
def read_toml(toml_path):
'''
Read an OpenCV .toml calibration file
Returns 5 lists of size N (N=number of cameras):
- S (image size),
- D (distorsion),
- K (intrinsic parameters),
- R (extrinsic rotation),
- T (extrinsic translation)
'''
calib = toml.load(toml_path)
C, S, D, K, R, T = [], [], [], [], [], []
for cam in list(calib.keys()):
if cam != 'metadata':
C += [calib[cam]['name']]
S += [np.array(calib[cam]['size'])]
D += [np.array(calib[cam]['distortions'])]
K += [np.array(calib[cam]['matrix'])]
R += [np.array(calib[cam]['rotation'])]
T += [np.array(calib[cam]['translation'])]
return C, S, D, K, R, T
def write_opencap_pickle(output_calibration_folder, C, S, D, K, R, T):
'''
Writes OpenCap .pickle calibration files
Extrinsics in OpenCap are calculated with a vertical board for the world frame.
As we want the world frame to be horizontal, we need to rotate cameras by -Pi/2 around x in the world frame.
T is good the way it is.
INPUTS:
- Path of the output calibration folder
- C: list of camera names
- S: list of image sizes
- D: list of distortion coefficients
- K: list of intrinsic parameters
- R (extrinsic rotation),
- T (extrinsic translation)
'''
for i in range(len(C)):
# Transform rotation for vertical frame of reference (checkerboard vertical with OpenCap)
R_mat = cv2.Rodrigues(R[i])[0] # transform in matrix
R_w, T_w = world_to_camera_persp(R_mat, T[i]) # transform in world centered perspective
R_w_90, T_w_90 = rotate_cam(R_w, T_w, ang_x=-np.pi/2, ang_y=0, ang_z=np.pi) # rotate cam wrt world frame
R_c, T_c = world_to_camera_persp(R_w_90, T_w_90) # transform in camera centered perspective
# retrieve data
calib_data = {'distortion': np.append(D[i],np.array([0])),
'intrinsicMat': K[i],
'imageSize': np.expand_dims(S[i][::-1], axis=1),
'rotation': R_c,
'translation': np.expand_dims(T[i], axis=1)*1000,
'rotation_EulerAngles': cv2.Rodrigues(R_c)[0] # OpenCap calls these Euler angles but they are actually the Rodrigues vector (Euler is ambiguous)
}
# write pickle
with open(os.path.join(output_calibration_folder, f'cam{i:02d}.pickle'), 'wb') as f_out:
pickle.dump(calib_data, f_out)
def calib_toml_to_opencap_func(*args):
'''
Convert an OpenCV .toml calibration file
to OpenCap .pickle calibration files.
One file will be created for each camera.
Usage:
from Pose2Sim.Utilities import calib_toml_to_opencap; calib_toml_to_opencap.calib_toml_to_opencap_func(r'<input_toml_file>')
OR python -m calib_toml_to_opencap -t input_toml_file
OR python -m calib_toml_to_opencap -t input_toml_file -o output_calibration_folder
'''
try:
toml_path = os.path.realpath(args[0].get('toml_file')) # invoked with argparse
if args[0]['output_calibration_folder'] == None:
output_calibration_folder = os.path.dirname(toml_path)
else:
output_calibration_folder = os.path.realpath(args[0]['output_calibration_folder'])
except:
toml_path = os.path.realpath(args[0]) # invoked as a function
output_calibration_folder = os.path.dirname(toml_path)
C, S, D, K, R, T = read_toml(toml_path)
write_opencap_pickle(output_calibration_folder, C, S, D, K, R, T)
print(f'OpenCap calibration files generated at {output_calibration_folder}.\n')
if __name__ == '__main__':
parser = argparse.ArgumentParser()
parser.add_argument('-t', '--toml_file', required = True, help='Input OpenCV .toml calibration file')
parser.add_argument('-o', '--output_calibration_folder', required = False, help='OpenCap calibration folder')
args = vars(parser.parse_args())
calib_toml_to_opencap_func(args)