ca_ur5/calibrate.py

108 lines
4.4 KiB
Python

import numpy as np
import cv2
from tqdm import tqdm
# Set the path to the images captured by the left and right cameras
pathL = "/home/ros/Bureau/ca_ur5/damier/Left/"
pathR = "/home/ros/Bureau/ca_ur5/damier/Right/"
print("Extracting image coordinates of respective 3D pattern ....\n")
# Termination criteria for refining the detected corners
criteria = (cv2.TERM_CRITERIA_EPS + cv2.TERM_CRITERIA_MAX_ITER, 30, 0.001)
objp = np.zeros((8*5,3), np.float32)
objp[:,:2] = np.mgrid[0:8,0:5].T.reshape(-1,2)
img_ptsL = []
img_ptsR = []
obj_pts = []
for i in tqdm(range(1,5)):
imgL = cv2.imread(pathL+"L%d.jpg"%i)
imgR = cv2.imread(pathR+"R%d.jpg"%i)
imgL_gray = cv2.imread(pathL+"L%d.jpg"%i,0)
imgR_gray = cv2.imread(pathR+"R%d.jpg"%i,0)
outputL = imgL.copy()
outputR = imgR.copy()
retR, cornersR = cv2.findChessboardCorners(outputR,(8,5),None)
retL, cornersL = cv2.findChessboardCorners(outputL,(8,5),None)
if retR and retL:
obj_pts.append(objp)
cv2.cornerSubPix(imgR_gray,cornersR,(11,11),(-1,-1),criteria)
cv2.cornerSubPix(imgL_gray,cornersL,(11,11),(-1,-1),criteria)
cv2.drawChessboardCorners(outputR,(8,5),cornersR,retR)
cv2.drawChessboardCorners(outputL,(8,5),cornersL,retL)
cv2.imshow('cornersR',outputR)
cv2.imshow('cornersL',outputL)
cv2.waitKey(0)
img_ptsL.append(cornersL)
img_ptsR.append(cornersR)
print("Calculating left camera parameters ... ")
# Calibrating left camera
retL, mtxL, distL, rvecsL, tvecsL = cv2.calibrateCamera(obj_pts,img_ptsL,imgL_gray.shape[::-1],None,None)
hL,wL= imgL_gray.shape[:2]
new_mtxL, roiL= cv2.getOptimalNewCameraMatrix(mtxL,distL,(wL,hL),1,(wL,hL))
print("Calculating right camera parameters ... ")
# Calibrating right camera
retR, mtxR, distR, rvecsR, tvecsR = cv2.calibrateCamera(obj_pts,img_ptsR,imgR_gray.shape[::-1],None,None)
hR,wR= imgR_gray.shape[:2]
new_mtxR, roiR= cv2.getOptimalNewCameraMatrix(mtxR,distR,(wR,hR),1,(wR,hR))
print("Stereo calibration .....")
flags = 0
flags |= cv2.CALIB_FIX_INTRINSIC
# Here we fix the intrinsic camara matrixes so that only Rot, Trns, Emat and Fmat are calculated.
# Hence intrinsic parameters are the same
criteria_stereo= (cv2.TERM_CRITERIA_EPS + cv2.TERM_CRITERIA_MAX_ITER, 30, 0.001)
# This step is performed to transformation between the two cameras and calculate Essential and Fundamenatl matrix
retS, new_mtxL, distL, new_mtxR, distR, Rot, Trns, Emat, Fmat = cv2.stereoCalibrate(obj_pts,
img_ptsL,
img_ptsR,
new_mtxL,
distL,
new_mtxR,
distR,
imgL_gray.shape[::-1],
criteria_stereo,
flags)
# Once we know the transformation between the two cameras we can perform stereo rectification
# StereoRectify function
rectify_scale= 1 # if 0 image croped, if 1 image not croped
rect_l, rect_r, proj_mat_l, proj_mat_r, Q, roiL, roiR= cv2.stereoRectify(new_mtxL, distL, new_mtxR, distR,
imgL_gray.shape[::-1], Rot, Trns,
rectify_scale,(0,0))
# Use the rotation matrixes for stereo rectification and camera intrinsics for undistorting the image
# Compute the rectification map (mapping between the original image pixels and
# their transformed values after applying rectification and undistortion) for left and right camera frames
Left_Stereo_Map= cv2.initUndistortRectifyMap(new_mtxL, distL, rect_l, proj_mat_l,
imgL_gray.shape[::-1], cv2.CV_16SC2)
Right_Stereo_Map= cv2.initUndistortRectifyMap(new_mtxR, distR, rect_r, proj_mat_r,
imgR_gray.shape[::-1], cv2.CV_16SC2)
print("Saving parameters ......")
cv_file = cv2.FileStorage("data/params_py.xml", cv2.FILE_STORAGE_WRITE)
cv_file.write("Left_Stereo_Map_x",Left_Stereo_Map[0])
cv_file.write("Left_Stereo_Map_y",Left_Stereo_Map[1])
cv_file.write("Right_Stereo_Map_x",Right_Stereo_Map[0])
cv_file.write("Right_Stereo_Map_y",Right_Stereo_Map[1])
cv_file.release()