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How to find contours of white object having little bit of black object?

I have white background with a black filled rectangle in the center. I need to have three contours of white regions. cv2.findContours gives one full contour of the whole image. How to use this cv2.findContours function?

import numpy as np

import cv2

white_img = np.ones((190, 640, 3), np.uint8) * 255

(rows, cols, channels) = white_img.shape

gray = cv2.cvtColor(white_img, cv2.COLOR_BGR2GRAY)

cv2.rectangle(gray, (320, 100), (380, 190), (0, 0, 0), cv2.FILLED)

contours, hierarchy = cv2.findContours(gray, cv2.RETR_TREE, cv2.CHAIN_APPROX_NONE)

print(len(contours))

for c in contours:

x, y, w, h = cv2.boundingRect(c)

cv2.rectangle(white_img, (x, y), (x + w, y + h), (0, 0, 255), 3)

cv2.imshow('white_img', white_img)

cv2.waitKey(0)

Input Image

image description

Output should be like this

image description

How to find contours of white object having little bit of black object?

import numpy as npnp import cv2 import cv2 white_img = np.ones((190, 640, 3), np.uint8) * 255255 (rows, cols, channels) = white_img.shapewhite_img.shape gray = cv2.cvtColor(white_img, cv2.COLOR_BGR2GRAY)cv2.COLOR_BGR2GRAY) cv2.rectangle(gray, (320, 100), (380, 190), (0, 0, 0), cv2.FILLED)cv2.FILLED) contours, hierarchy = cv2.findContours(gray, cv2.RETR_TREE, cv2.CHAIN_APPROX_NONE)cv2.CHAIN_APPROX_NONE) print(len(contours)) print(len(contours)) for c in contours:contours: x, y, w, h = cv2.boundingRect(c) cv2.rectangle(white_img, (x, y), (x + w, y + h), (0, 0, 255), 3) cv2.imshow('white_img', white_img) cv2.waitKey(0) cv2.imshow('white_img', white_img) cv2.waitKey(0) Input Image Output should be like this

          3    None 
      updated 
        2019-02-16 20:49:40 -0600
     
 
 
  
 
 
 
  How to find contours of white object having little bit of black object?
 I have white background with a black filled rectangle in the center. I need to have three contours of white regions. cv2.findContours gives one full contour of the whole image. How to use this cv2.findContours function?
 import numpy as np

import cv2

white_img = np.ones((190, 640, 3), np.uint8) * 255

(rows, cols, channels) = white_img.shape

gray = cv2.cvtColor(white_img, cv2.COLOR_BGR2GRAY)

cv2.rectangle(gray, (320, 100), (380, 190), (0, 0, 0), cv2.FILLED)

contours, hierarchy = cv2.findContours(gray, cv2.RETR_TREE, cv2.CHAIN_APPROX_NONE)

print(len(contours))

for c in contours:

    x, y, w, h = cv2.boundingRect(c)

    cv2.rectangle(white_img, (x, y), (x + w, y + h), (0, 0, 255), 3)

cv2.imshow('white_img', white_img)

cv2.waitKey(0)
 Input Image
 
 Output should be like this
 
  Other input could be like
 
 Its output should be
 
 
 
 
          4    None 
      updated 
        2019-02-16 20:51:21 -0600
     
 
 
  
 
 
 
  How to find contours of white object having little bit of black object?
 I have white background with a black filled rectangle in the center. I need to have three contours of white regions. cv2.findContours gives one full contour of the whole image. How to use this cv2.findContours function?
 import numpy as np

import cv2

white_img = np.ones((190, 640, 3), np.uint8) * 255

(rows, cols, channels) = white_img.shape

gray = cv2.cvtColor(white_img, cv2.COLOR_BGR2GRAY)

cv2.rectangle(gray, (320, 100), (380, 190), (0, 0, 0), cv2.FILLED)

contours, hierarchy = cv2.findContours(gray, cv2.RETR_TREE, cv2.CHAIN_APPROX_NONE)

print(len(contours))

for c in contours:

    x, y, w, h = cv2.boundingRect(c)

    cv2.rectangle(white_img, (x, y), (x + w, y + h), (0, 0, 255), 3)

cv2.imshow('white_img', white_img)

cv2.waitKey(0)
 Input Image
 
 Output should be like this
 
 Other input could be like
 
 Its output should be