添加挑战任务1内容 2018年1月29日

挑战任务1：画动态时钟/cv2_time_clock.py

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+# ex2tron's blog:
+# http://ex2tron.wang
+
+import cv2
+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
+cv2.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)
+
+    cv2.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
+    cv2.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)
+    cv2.line(temp, center, (int(sec_x), int(sec_y)), (203, 222, 166), 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)
+    cv2.line(temp, center, (int(min_x), int(min_y)), (186, 199, 137), 8)
+
+    # 画时刻线
+    hour_angle = hour*30+270 if hour <= 3 else (hour-3)*30
+    hour_x = center_x+(radius-65)*math.cos(hour_angle*np.pi/180.0)
+    hour_y = center_y+(radius-65)*math.sin(hour_angle*np.pi/180.0)
+    cv2.line(temp, center, (int(hour_x), int(hour_y)), (169, 198, 26), 15)
+
+    # 6. 添加当前日期文字
+    font = cv2.FONT_HERSHEY_SIMPLEX
+    time_str = now_time.strftime("%d/%m/%Y")
+    cv2.putText(img, time_str, (135, 275), font, 1, (0, 0, 0), 2)
+
+    cv2.imshow('clocking', temp)
+    if cv2.waitKey(1) == 27:  # 按下ESC键退出
+        break