python - Reg：根据 blob 大小的区域复制 blob

Question

目标：在另一个蒙版图像中复制较大的斑点

我有一个带有斑点的阈值图像，如图所示：

我怎样才能将较大的斑点复制到蒙版图像中并省略一个像素的斑点？

我的代码（但我没有得到想要的结果）：

import numpy as np
import cv2

ref_img = cv2.imread('threshold.jpg', 0)
thresh = np.copy(ref_img)
cnts,_ = cv2.findContours(ref_img, cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)
mask = np.zeros(ref_img.shape, dtype="uint8")
for c in cnts:
   (x,y),radius = cv2.minEnclosingCircle(c)
   area = cv2.contourArea(c)
   if int(area) < 1:
      cv2.circle(mask, (int(x), int(y)), int(radius), (255, 255, 255), -1)

cv2.imshow('img', mask)
cv2.waitKey(0)

注意：使用 OpenCV 2.4.x

Answer 1

这是您可以用来实现目标的方法之一。代码注释中提供了解释

import numpy as np
import cv2

ref_img = cv2.imread('threshold.jpg', 0)


img, cnts,_ = cv2.findContours(ref_img, cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)
mask = np.zeros(ref_img.shape, dtype="uint8")
for c in cnts:
   # Get the bounding rect surrounding your blobs
   x,y,w,h = cv2.boundingRect(c) 

   # Calculating the area of the rect is similar to the area of the blob minus the complexity
   area = w*h

   # For box area bigger than one, copy the information from the source image to the mask. 
   # Since the bounding box contains all the relevant information, just copy the entire box to the mask.
   if int(area) > 1 :
    mask[y:y+h,x:x+w] = ref_img[y:y+h,x:x+w]




cv2.imshow('img', mask)
cv2.waitKey(0)