OpenCV-Python学习（13）—— OpenCV 多边形填充与绘制(cv.fillPoly、cv.polylines)

cv.polylines(img, pts, isClosed, color[, thickness[, lineType[, shift]]]) → img

cv.fillPoly(img, pts, color[, lineType[, shift[, offset]]]) → img

import cv2 as cv
import numpy as np

# 以五角星的重心为原点，计算各点坐标
def get_star_point(r = 100):
  # 计算没一份的度数和内五边形的r
  pi_val = np.pi / 180
  min_r = r * np.sin(18 * pi_val) / np.cos(36 * pi_val)
  # 外五边形的坐标
  a = [0,r]
  b = [r * np.cos(18 * pi_val), r * np.sin(18 * pi_val)]
  c = [r * np.cos(54 * pi_val), - r * np.sin(54 * pi_val)]
  d = [- r * np.cos(54 * pi_val), - r * np.sin(54 * pi_val)]
  e = [- r * np.cos(18 * pi_val), r * np.sin(18 * pi_val)]
  # 内五边形的坐标
  in_a = [min_r * np.cos(54 * pi_val),min_r * np.sin(54 * pi_val)]
  in_b = [min_r * np.cos(18 * pi_val),- min_r * np.sin(18 * pi_val)]
  in_c = [0, - min_r]
  in_d = [- min_r * np.cos(18 * pi_val),- min_r * np.sin(18 * pi_val)]
  in_e = [- min_r * np.cos(54 * pi_val),min_r * np.sin(54 * pi_val)]
  return {
    "out": [a, b, c, d, e],
    "in": [in_a, in_b, in_c, in_d, in_e]
  }

# 绘制五边形
def create_pentagon(a,b,c,d,e,isClosed=True,color=(0,0,255),fill=False,fillColor=(255,0,0)):
  img = np.ones((200, 200, 3), np.uint8)*255
  pts = np.array([a,b,c,d,e])
  # 向左上角移动100像素原点
  pts[:,:] += 100
  cv.polylines(img, [pts], isClosed, color,1)
  # 判断是否填充多边形
  if fill:
    cv.fillPoly(img,[pts],fillColor)
  return img

def create_five_pointed_star(a,b,c,d,e,
isClosed=True,
color=(0,0,255),
fill=False,
fillColor=(255,0,0)):
  img = np.ones((200, 200, 3), np.uint8)*255
  pts = np.array([a,c,e,b,d])
  # 向左上角移动100像素原点
  pts[:,:] += 100
  cv.polylines(img, [pts], isClosed, color,1)
  # 判断是否填充多边形
  if fill:
    cv.fillPoly(img,[pts],fillColor)
  return img

def create_five_pointed_star_all(
  a,b,c,d,e,
  in_a,in_b,in_c,in_d,in_e,
  isClosed=True,
  color=(0,0,255),
  fill=False,
  fillColor=(255,0,0)):
  img = np.ones((200, 200, 3), np.uint8)*255
  pts = np.array([a,in_a,b,in_b,c,in_c,d,in_d,e,in_e])
  # 向左上角移动100像素原点
  pts[:,:] += 100
  cv.polylines(img, [pts], isClosed, color,1)
  # 判断是否填充多边形
  if fill:
    cv.fillPoly(img,[pts],fillColor)
  return img

def create_demo():
  # 以五角星长轴半径计算各点坐标，注意计算坐标需要倒转
  star_points = get_star_point(60)
  [a,b,c,d,e] = list(map(lambda items: list(map(lambda val: - int(val), items)), star_points.get("out")))
  [in_a, in_b, in_c, in_d, in_e] = list(map(lambda items: list(map(lambda val: - int(val), items)), star_points.get("in")))
  # 
  img = np.ones((600, 600, 3), np.uint8)*255
  # 不闭合折线
  # 五角星【线交叉】
  img[0:200,0:200] = create_five_pointed_star(a,b,c,d,e,isClosed=False)
  # 五边形
  img[200:400,0:200] = create_pentagon(a,b,c,d,e,isClosed=False)
  # 五角星【十点】
  img[400:600,0:200] = create_five_pointed_star_all(a,b,c,d,e,in_a,in_b,in_c,in_d,in_e,isClosed=False)

  # 闭合多边形
  # 五角星【线交叉】
  img[0:200,200:400] = create_five_pointed_star(a,b,c,d,e)
  # 五边形
  img[200:400,200:400] = create_pentagon(a,b,c,d,e)
  # 五角星【十点】
  img[400:600,200:400] = create_five_pointed_star_all(a,b,c,d,e,in_a,in_b,in_c,in_d,in_e)

  # # 闭合填充多边形
  # # 五角星【线交叉】
  img[0:200,400:600] = create_five_pointed_star(a,b,c,d,e,fill=True)
  # 五边形
  img[200:400,400:600] = create_pentagon(a,b,c,d,e,fill=True)
  # 五角星【十点】
  img[400:600,400:600] = create_five_pointed_star_all(a,b,c,d,e,in_a,in_b,in_c,in_d,in_e,fill=True)

  cv.imshow("img", img)
  cv.waitKey(0)
  cv.destroyAllWindows()

if __name__ == "__main__":
  create_demo()