How To Delete The Other Object From Figure By Using Opencv?

I tried to detect the yellow lines in the following picture but the logo(yellow color) will be marked as well. My question is that how to mask the logo? I use the standard code

Solution 1:

You can use multi-scale template matching approach.

You want to remove the following image:

• 1. Detect the image

  import cv2
  import imutils
  import numpy as np
  
  template = cv2.imread("template/template.jpg")
  template = cv2.cvtColor(template, cv2.COLOR_BGR2GRAY)
  template = cv2.Canny(template, 50, 200)
  (h, w) = template.shape[:2]
  
  image = cv2.imread('nnEGw.jpg')
  gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
  found = Nonefor scale in np.linspace(0.2, 1.0, 20)[::-1]:
       resized = imutils.resize(gray, width=int(gray.shape[1] * scale))
       r = gray.shape[1] / float(resized.shape[1])
  
       if resized.shape[0] < h or resized.shape[1] < w:
           break
  
       edged = cv2.Canny(resized, 50, 200)
       result = cv2.matchTemplate(edged, template, cv2.TM_CCOEFF)
       (_, maxVal, _, maxLoc) = cv2.minMaxLoc(result)
  
       if found isNoneor maxVal > found[0]:
           found = (maxVal, maxLoc, r)
  
  (_, maxLoc, r) = found
  (startX, startY) = (int(maxLoc[0] * r), int(maxLoc[1] * r))
  (endX, endY) = (int((maxLoc[0] + w) * r), int((maxLoc[1] + h) * r))
  
  cv2.rectangle(image, (startX, startY), (endX, endY), (0, 0, 255), 2)
  cv2.imwrite("result/edges2.png", image)
  

  

  • 2. Fill the rectangle

  cv2.rectangle(image, (startX, startY), (endX, endY), (255, 255, 255), -1)
  

  

  • 3. Apply Hough Transform

  hsv = cv2.cvtColor(image, cv2.COLOR_BGR2HSV)
  
  low_yellow = np.array([18, 94, 140])
  up_yellow = np.array([48, 255, 255])
  mask = cv2.inRange(hsv, low_yellow, up_yellow)
  edges = cv2.Canny(mask, 75, 150)
  
  lines = cv2.HoughLinesP(edges, 1, np.pi / 180, 50, maxLineGap=250)
  for line in lines:
      x1, y1, x2, y2 = line[0]
      cv2.line(image, (x1, y1), (x2, y2), (0, 255, 0), 5)
  
      # cv2.imshow('image', img)
      cv2.imwrite("result/edges3.png", edges)