填充过滤轮廓的内部 OpenCV Python

Question

I have an image that has green borders which encapsulates the items that has to be deleted. I have filtered the only green part of the image so my next step is to fill inside of the filtered contour with a different color then I will remove that part from the image? I am very open the any suggestions. Here is my code

import cv2
import numpy as np
import imageio

## Read
img = cv2.imread("test.png",-1)
img2 = imageio.imread("test.png")
## convert to hsv
hsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV)

## mask of green (36,25,25) ~ (86, 255,255)
# mask = cv2.inRange(hsv, (36, 25, 25), (86, 255,255))
mask = cv2.inRange(hsv, (36, 25, 25), (70, 255,255))

## slice the green
imask = mask>0
green = np.zeros_like(img, np.uint8)
green[imask] = img[imask]

green_filter=img[100,100,0]
print(green_filter)


## save 
cv2.imshow('image', green)
cv2.imshow('  ',img)
cv2.waitKey(0)
print(img)
print(green)

image i have: https://ibb.co/vJX1jM4 image i reached currently: https://ibb.co/FnScYHc

Answer 1

import cv2
import numpy as np
import matplotlib.pyplot as plt
import imageio

## Read
img = cv2.imread("test.png",-1)
## convert to hsv
hsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV)

mask = cv2.inRange(hsv, (36, 25, 25), (70, 255,255))
contours, _ = cv2.findContours(mask, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_NONE) 
idx = 0 
mask1 = np.zeros_like(img) 

cv2.drawContours(mask1, contours, idx, (255,255,255), -1) 
out = np.zeros_like(img)
out[mask1 == (255,255,255)] = img[mask1 == 255]

fig, axs = plt.subplots(1, 3, figsize=(16, 4))
for ax, image in zip(axs, ['img', 'mask1', 'out']):
    ax.imshow(eval(image))
    ax.set_title(image)
    ax.grid(True)

plt.show()

=>

I let you play around with this snippet, especially if you want to remove your green contour.

If you want to reverse the kept area, you need to replace:
out[mask1 == (255,255,255)] = img[mask1 == 255]
by:
out[mask1 == (0,0,0)] = img[mask1 == 0]
(see second figure below)

I just imported matplotlib for convenience here.

Answer 2

Sorry for the quick and dirty sudo code here, but this is generally how you would go about it.

Load in image
Convert to grayscale
Find Contours
Find the index of the contour you want to fill
Use fillConvexPoly to fill the specific contour with the index found above.

Here is some code that can guide you in the right direction.

#Read in the image
img = cv2.imread("test.png")

#Convert to grayscale
grayImg = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

#Find contours
contours = cv2.findContours(edged, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_NONE)

#Find contour index that you want
#I didn't put code here because I don't know what index would work for your image,
#But you can manually find it by just drawing each contour found one by one until
#You get the contour you want, then use that index to fill it.

#Fill the contour
#NOTE: You will have to adjust this function for your own code
cv2.fillConvexPoly(img, contours[index], lineType=8, shift=0)