如何在python中的感兴趣区域周围绘制一个矩形

2 回答

• 79

  请不要尝试旧的cv模块，使用cv2：

  import cv2
  
  cv2.rectangle(img, (x1, y1), (x2, y2), (255,0,0), 2)
  
  
  x1,y1 ------
  |          |
  |          |
  |          |
  --------x2,y2
  

  [编辑]追加以下后续问题：

  cv2.imwrite("my.png",img)
  
  cv2.imshow("lalala", img)
  k = cv2.waitKey(0) # 0==wait forever
  

  回复于 2024-05-03T11:57:49+08:00
• 1

  你可以使用cv2.rectangle()：

  cv2.rectangle(img, pt1, pt2, color, thickness, lineType, shift)
  
  Draws a simple, thick, or filled up-right rectangle.
  
  The function rectangle draws a rectangle outline or a filled rectangle
  whose two opposite corners are pt1 and pt2.
  
  Parameters
      img   Image.
      pt1   Vertex of the rectangle.
      pt2    Vertex of the rectangle opposite to pt1 .
      color Rectangle color or brightness (grayscale image).
      thickness  Thickness of lines that make up the rectangle. Negative values,
      like CV_FILLED , mean that the function has to draw a filled rectangle.
      lineType  Type of the line. See the line description.
      shift   Number of fractional bits in the point coordinates.
  

  我有一个PIL Image对象，我想在这个图像上绘制矩形，但是PIL的ImageDraw.rectangle()方法无法指定线宽 . I need to convert Image object to opencv2's image format and draw rectangle and convert back to Image object . 我是这样做的：

  # im is a PIL Image object
  im_arr = np.asarray(im)
  # convert rgb array to opencv's bgr format
  im_arr_bgr = cv2.cvtColor(im_arr, cv2.COLOR_RGB2BGR)
  # pts1 and pts2 are the upper left and bottom right coordinates of the rectangle
  cv2.rectangle(im_arr_bgr, pts1, pts2),
                color=(0, 255, 0), thickness=3)
  im_arr = cv2.cvtColor(im_arr_bgr, cv2.COLOR_BGR2RGB)
  # convert back to Image object
  im = Image.fromarray(im_arr)
  

  回复于 2024-05-03T11:57:49+08:00