在opencv python中矫正轮廓矩形

1 回答

• 1

  这里是解决您问题的代码：

  import cv2
  import numpy as np
  
  # get the minimum bounding box for the chip image
  image = cv2.imread("./chip1.png", cv2.IMREAD_COLOR)
  image = image[10:-10,10:-10]
  imgray = cv2.cvtColor(image, cv2.COLOR_BGR2LAB)[...,0]
  ret, thresh = cv2.threshold(imgray, 20, 255, cv2.THRESH_BINARY|cv2.THRESH_OTSU)
  mask = 255 - thresh
  _, contours, _ = cv2.findContours(mask, cv2.RETR_TREE, cv2.CHAIN_APPROX_NONE)
  
  maxArea = 0
  best = None
  for contour in contours:
    area = cv2.contourArea(contour)
    if area > maxArea :
      maxArea = area
      best = contour
  
  rect = cv2.minAreaRect(best)
  box = cv2.boxPoints(rect)
  box = np.int0(box)
  
  #crop image inside bounding box
  scale = 1  # cropping margin, 1 == no margin
  W = rect[1][0]
  H = rect[1][1]
  
  Xs = [i[0] for i in box]
  Ys = [i[1] for i in box]
  x1 = min(Xs)
  x2 = max(Xs)
  y1 = min(Ys)
  y2 = max(Ys)
  
  angle = rect[2]
  rotated = False
  if angle < -45:
      angle += 90
      rotated = True
  
  center = (int((x1+x2)/2), int((y1+y2)/2))
  size = (int(scale*(x2-x1)), int(scale*(y2-y1)))
  
  M = cv2.getRotationMatrix2D((size[0]/2, size[1]/2), angle, 1.0)
  
  cropped = cv2.getRectSubPix(image, size, center)
  cropped = cv2.warpAffine(cropped, M, size)
  
  croppedW = W if not rotated else H
  croppedH = H if not rotated else W
  
  image = cv2.getRectSubPix(
      cropped, (int(croppedW*scale), int(croppedH*scale)), (size[0]/2, size[1]/2))
  
  # show result
  while True:
    cv2.imshow("result", image)
    k = cv2.waitKey(30) & 0xff
    if k == 27:
        break
  

  这里结果图片：
  

  回复于 2024-05-15T09:13:08+08:00