poseEstimation.py

import numpy as np
import cv2 as cv
import glob

chessboardsize  = (6,8)

# Load previously saved data
with np.load('matrix\params.npz') as file:
    mtx, dist, rvecs, tvecs = [file[i] for i in ('mtx','dist','rvecs','tvecs')]


def draw(img, corners, imgpts):
    corner = tuple(corners[0].ravel().astype(int))

    img = cv.line(img, corner, tuple(imgpts[0].ravel().astype(int)), (255,0,0), 5) # x
    img = cv.line(img, corner, tuple(imgpts[1].ravel().astype(int)), (0,255,0), 5) # y
    img = cv.line(img, corner, tuple(imgpts[2].ravel().astype(int)), (0,0,255), 5) # z
    return img


def drawBoxes(img, corners, imgpts):

    imgpts = np.int32(imgpts).reshape(-1,2)

    # draw ground floor in green
    img = cv.drawContours(img, [imgpts[:4]],-1,(0,255,0),-3)

    # draw pillars in blue color
    for i,j in zip(range(4),range(4,8)):
        img = cv.line(img, tuple(imgpts[i]), tuple(imgpts[j]),(255),3)

    # draw top layer in red color
    img = cv.drawContours(img, [imgpts[4:]],-1,(0,0,255),3)

    return img



criteria = (cv.TERM_CRITERIA_EPS + cv.TERM_CRITERIA_MAX_ITER, 30, 0.001)

objp = np.zeros((chessboardsize[0]*chessboardsize[1],3), np.float32)
objp[:,:2] = np.mgrid[0:chessboardsize[0],0:chessboardsize[1]].T.reshape(-1,2)

axis = np.float32([[3,0,0], [0,3,0], [0,0,-3]]).reshape(-1,3)
axisBoxes = np.float32([[0,0,0], [0,3,0], [3,3,0], [3,0,0],
                   [0,0,-3],[0,3,-3],[3,3,-3],[3,0,-3] ])


for fname in glob.glob('input\DJI_0112.jpg'):
    print(fname)
    img = cv.imread(fname)
    gray = cv.cvtColor(img,cv.COLOR_BGR2GRAY)
    ret, corners = cv.findChessboardCorners(gray, chessboardsize,None)

    if ret == True:

        corners2 = cv.cornerSubPix(gray,corners,(11,11),(-1,-1), criteria)

        # Find the rotation and translation vectors.
        ret, rvecs, tvecs = cv.solvePnP(objp, corners2, mtx, dist)

        # Project 3D points to image plane
        imgpts, jac = cv.projectPoints(axis, rvecs, tvecs, mtx, dist)

        img = draw(img,corners2,imgpts)
        cv.imshow('img',img)

        k = cv.waitKey(0) & 0xFF
        if k == ord('s'):
            cv.imwrite('pose'+fname, img)

cv.destroyAllWindows()