python opencv图像表格处理
Opencv-Python图像透视变换cv2.warpPerspective的示例opencv-python图像透视变换cv2.warpperspective
代码如下：
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# -*- coding:utf-8 -*-import cv2import numpy as npimport sysimg = cv2.imread('test.jpg" alt="python opencv图像表格处理（Opencv-Python图像透视变换cv2.warpPerspective的示例）" border="0" /># 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 = 0angley = 30anglez = 0 # 是旋转fov = 42r = 0def rad(x): return x * np.pi / 180def 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 warprdef 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() |
运行效果：
控制：
- s控制垂直方向上的形变
- a和d控制水平方向上的行变
- u和p控制角度旋转
- e 输出当前旋转矩阵参数
总结
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原文链接：https://blog.csdn.net/dcrmg/article/details/80273818