demo2.py

#
# Author Stephan Janssen
#
import cv2
import numpy as np
import matplotlib.pyplot as plt

# Read source image.
img_src = cv2.imread('images/3DBasketballMiddleView.jpg')

# Four corners of the 3D court + mid-court circle point in source image
# Start top-left corner and go anti-clock wise + mid-court circle point
pts_src = np.array([
    [1, 258],       # left bottom - bottom corner
    [400, 308],     # middle bottom corner
    [798, 280],     # right bottom - bottom corner
    [798, 220],     # right bottom - top corner
    [612, 176],     # top right rorner
    [186, 168],     # top left corner
    [3, 201]        # left bottom - top corner
    ])   

# cv2.fillPoly(img_src, [pts_src], 255)
cv2.polylines(img_src, [pts_src], isClosed=True, color=[255,0,0], thickness=2)

plt.imshow(img_src)
plt.title('Original')
plt.show()

# Read destination image.
img_dst = cv2.imread('images/2DCourtBasketball.jpg')

# Four corners of the court + mid-court circle point in destination image 
# Start top-left corner and go anti-clock wise + mid-court circle point
pts_dst = np.array([
    [43, 355],       # left bottom - bottom corner
    [317, 351],      # middle bottom corner
    [563, 351],     # right bottom - bottom corner
    [629, 293],     # right bottom - top corner
    [628, 3],     # top right rorner
    [8, 4],     # top left corner
    [2, 299]        # left bottom - top corner
    ])   

cv2.fillPoly(img_dst, [pts_dst], 255)

plt.figure()
plt.imshow(img_dst)
plt.show()

# Calculate Homography
h, status = cv2.findHomography(pts_src, pts_dst)
  
# Warp source image to destination based on homography
img_src2 = cv2.imread('images/3DBasketballMiddleView.jpg')
img_out = cv2.warpPerspective(img_src2, h, (img_dst.shape[1], img_dst.shape[0]))
cv2.imshow("Warped", img_out)
cv2.waitKey(0)

cv2.imwrite("output/middleViewResult.jpg", img_out)