• 影像處理課程(以 OpenCV 為例)

畫圖

• 講義

• 畫直線

  程式碼

  import numpy as np
  import cv2 as cv
   
  # Create a black image
  img = np.zeros((512,512,3), np.uint8)
   
  # Draw a diagonal blue line with thickness of 5 px
  cv.line(img,(0,0),(511,511),(255,0,0),5)

  畫長方形

  程式碼

  cv.rectangle(img,(384,0),(510,128),(0,255,0),3)

  畫圓形

  程式碼

  cv.circle(img,(447,63), 63, (0,0,255), -1)

  畫橢圓形

  程式碼

  cv.ellipse(img,(256,256),(100,50),0,0,180,255,-1)

  畫多邊形

  程式碼

  pts = np.array([[10,5],[20,30],[70,20],[50,10]], np.int32)
  pts = pts.reshape((-1,1,2))
  cv.polylines(img,[pts],True,(0,255,255))

  寫文字

  程式碼

  font = cv.FONT_HERSHEY_SIMPLEX
  cv.putText(img,'OpenCV',(10,500), font, 4,(255,255,255),2,cv.LINE_AA)