python基于opencv 实现图像时钟

import cv2 as cv
import math
import datetime
import numpy as np

margin = 5 # 上下左右边距
radius = 220 # 圆的半径
center = (center_x, center_y) = (225, 225) # 圆心

# 1. 新建一个画板并填充成白色
img = np.zeros((450, 450, 3), np.uint8)
img[:] = (255, 255, 255)

# 2. 画出圆盘
cv.circle(img, center, radius, (0, 0, 0), thickness=5)

pt1 = []

# 3. 画出60条秒和分钟的刻线
for i in range(60):
  # 最外部圆，计算A点
  x1 = center_x+(radius-margin)*math.cos(i*6*np.pi/180.0)
  y1 = center_y+(radius-margin)*math.sin(i*6*np.pi/180.0)
  pt1.append((int(x1), int(y1)))

  # 同心小圆，计算B点
  x2 = center_x+(radius-15)*math.cos(i*6*np.pi/180.0)
  y2 = center_y+(radius-15)*math.sin(i*6*np.pi/180.0)

  cv.line(img, pt1[i], (int(x2), int(y2)), (0, 0, 0), thickness=2)

# 4. 画出12条小时的刻线
for i in range(12):
  # 12条小时刻线应该更长一点
  x = center_x+(radius-25)*math.cos(i*30*np.pi/180.0)
  y = center_y+(radius-25)*math.sin(i*30*np.pi/180.0)
  # 这里用到了前面的pt1
  cv.line(img, pt1[i*5], (int(x), int(y)), (0, 0, 0), thickness=5)


# 到这里基本的表盘图就已经画出来了

while(1):
  # 不断拷贝表盘图，才能更新绘制，不然会重叠在一起
  temp = np.copy(img)

  # 5. 获取系统时间，画出动态的时-分-秒三条刻线
  now_time = datetime.datetime.now()
  hour, minute, second = now_time.hour, now_time.minute, now_time.second

  # 画秒刻线
  # 参见博客，OpenCV中的角度是顺时针计算的，所以需要转换下
  sec_angle = second*6+270 if second <= 15 else (second-15)*6
  sec_x = center_x+(radius-margin)*math.cos(sec_angle*np.pi/180.0)
  sec_y = center_y+(radius-margin)*math.sin(sec_angle*np.pi/180.0)
  cv.line(temp, center, (int(sec_x), int(sec_y)), (255, 0, 0), 2)

  # 画分刻线
  min_angle = minute*6+270 if minute <= 15 else (minute-15)*6
  min_x = center_x+(radius-35)*math.cos(min_angle*np.pi/180.0)
  min_y = center_y+(radius-35)*math.sin(min_angle*np.pi/180.0)
  cv.line(temp, center, (int(min_x), int(min_y)), (0, 255, 0), 8)

  # 画时刻线
  hour_angle = hour*30+270 if hour <= 3 else (hour-3)*30
  hour_x = center_x+(radius-75)*math.cos(hour_angle*np.pi/180.0)
  hour_y = center_y+(radius-75)*math.sin(hour_angle*np.pi/180.0)
  cv.line(temp, center, (int(hour_x), int(hour_y)), (0, 0, 255), 20)

  # 6. 添加当前日期文字
  font = cv.FONT_HERSHEY_SIMPLEX
  time_str = now_time.strftime("%d/%m/%Y")
  cv.putText(img, time_str, (135, 275), font, 1, (0, 0, 0), 2)

  cv.imshow('clocking', temp)
  if cv.waitKey(1) == 27: # 按下ESC键退出
    break