recammat.py

import numpy as np
import cv2
import glob

def recammat():

    # termination criteria
    criteria = (cv2.TERM_CRITERIA_EPS + cv2.TERM_CRITERIA_MAX_ITER, 30, 0.001)

    # prepare object points, like (0,0,0), (1,0,0), (2,0,0) ....,(6,5,0)
    objp = np.zeros((7*9,3), np.float32)
    objp[:,:2] = np.mgrid[0:9,0:7].T.reshape(-1,2)*20 #20 mm of square

    # Arrays to store object points and image points from all the images.
    objpoints = [] # 3d point in real world space
    imgpoints = [] # 2d points in image plane.

    images = glob.glob('calib_images/*.jpg')

    for fname in images:
        img = cv2.imread(fname)
        gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)

        # Find the chess board corners
        ret, corners = cv2.findChessboardCorners(gray, (9,7),None)

        # If found, add object points, image points (after refining them)
        if ret == True:
            objpoints.append(objp)

            corners2 = cv2.cornerSubPix(gray,corners,(11,11),(-1,-1),criteria)
            imgpoints.append(corners2)

            # Draw and display the corners 可以取消掉
            #img = cv2.drawChessboardCorners(img, (9,7), corners2,ret)
            #cv2.imshow('img',img)
            #cv2.waitKey(700)

    #cv2.destroyAllWindows()

    ret, mtx, dist, rvecs, tvecs = cv2.calibrateCamera(objpoints, imgpoints, gray.shape[::-1],None,None)
    return mtx, dist