Opencv-Python图像透视变换cv2.warpPerspective的示例_Python

opencv-python图像透视变换cv2.warpperspective

代码如下：

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									# -*- coding:utf-8 -*-

									import cv2

									import numpy as np

									import sys

									img = cv2.imread('test.jpg')

									# cv2.imshow("original", img)

									# 可选，扩展图像，保证内容不超出可视范围

									img = cv2.copymakeborder(img, 200, 200, 200, 200, cv2.border_constant, 0)

									w, h = img.shape[0:2]

									anglex = 0

									angley = 30

									anglez = 0 # 是旋转

									fov = 42

									r = 0

									def rad(x):

									  return x * np.pi / 180

									def get_warpr():

									  global anglex,angley,anglez,fov,w,h,r

									  # 镜头与图像间的距离，21为半可视角，算z的距离是为了保证在此可视角度下恰好显示整幅图像

									  z = np.sqrt(w ** 2 + h ** 2) / 2 / np.tan(rad(fov / 2))

									  # 齐次变换矩阵

									  rx = np.array([[1, 0, 0, 0],

									          [0, np.cos(rad(anglex)), -np.sin(rad(anglex)), 0],

									          [0, -np.sin(rad(anglex)), np.cos(rad(anglex)), 0, ],

									          [0, 0, 0, 1]], np.float32)

									  ry = np.array([[np.cos(rad(angley)), 0, np.sin(rad(angley)), 0],

									          [0, 1, 0, 0],

									          [-np.sin(rad(angley)), 0, np.cos(rad(angley)), 0, ],

									          [0, 0, 0, 1]], np.float32)

									  rz = np.array([[np.cos(rad(anglez)), np.sin(rad(anglez)), 0, 0],

									          [-np.sin(rad(anglez)), np.cos(rad(anglez)), 0, 0],

									          [0, 0, 1, 0],

									          [0, 0, 0, 1]], np.float32)

									  r = rx.dot(ry).dot(rz)

									  # 四对点的生成

									  pcenter = np.array([h / 2, w / 2, 0, 0], np.float32)

									  p1 = np.array([0, 0, 0, 0], np.float32) - pcenter

									  p2 = np.array([w, 0, 0, 0], np.float32) - pcenter

									  p3 = np.array([0, h, 0, 0], np.float32) - pcenter

									  p4 = np.array([w, h, 0, 0], np.float32) - pcenter

									  dst1 = r.dot(p1)

									  dst2 = r.dot(p2)

									  dst3 = r.dot(p3)

									  dst4 = r.dot(p4)

									  list_dst = [dst1, dst2, dst3, dst4]

									  org = np.array([[0, 0],

									          [w, 0],

									          [0, h],

									          [w, h]], np.float32)

									  dst = np.zeros((4, 2), np.float32)

									  # 投影至成像平面

									  for i in range(4):

									    dst[i, 0] = list_dst[i][0] * z / (z - list_dst[i][2]) + pcenter[0]

									    dst[i, 1] = list_dst[i][1] * z / (z - list_dst[i][2]) + pcenter[1]

									  warpr = cv2.getperspectivetransform(org, dst)

									  return warpr

									def control():

									  global anglex,angley,anglez,fov,r

									  # 键盘控制

									  if 27 == c: # esc quit

									    sys.exit()

									  if c == ord('w'):

									    anglex += 1

									  if c == ord('s'):

									    anglex -= 1

									  if c == ord('a'):

									    angley += 1

									    print(angley)

									    # dx=0

									  if c == ord('d'):

									    angley -= 1

									  if c == ord('u'):

									    anglez += 1

									  if c == ord('p'):

									    anglez -= 1

									  if c == ord('t'):

									    fov += 1

									  if c == ord('r'):

									    fov -= 1

									  if c == ord(' '):

									    anglex = angley = anglez = 0

									  if c == ord('e'):

									    print("======================================")

									    print('rotation matrix:')

									    print(r)

									    print('angle alpha(anglex):')

									    print(anglex)

									    print('angle beta(angley):')

									    print(angley)

									    print('dz(anglez):')

									    print(anglez)

									while true:

									  warpr = get_warpr()

									  result = cv2.warpperspective(img, warpr, (h, w))

									  cv2.namedwindow('result',2)

									  cv2.imshow("result", result)

									  c = cv2.waitkey(30)

									  control()

									cv2.destroyallwindows()