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Can anyone give me advice on how to crop the two rectangular boxes and save it?

sample image

I already tried this code, but it does not crop very well

import cv2;
import numpy as np;

# Run the code with the image name, keep pressing space bar

# Change the kernel, iterations, Contour Area, position accordingly
# These values work for your present image

img = cv2.imread("your_image.jpg", 0);
h, w = img.shape[:2]
kernel = np.ones((15,15),np.uint8)

e = cv2.erode(img,kernel,iterations = 2)  
d = cv2.dilate(e,kernel,iterations = 1)
ret, th = cv2.threshold(d, 150, 255, cv2.THRESH_BINARY_INV)

mask = np.zeros((h+2, w+2), np.uint8)
cv2.floodFill(th, mask, (200,200), 255); # position = (200,200)
out = cv2.bitwise_not(th)
out= cv2.dilate(out,kernel,iterations = 3)
cnt, h = cv2.findContours(out,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)
for i in range(len(cnt)):
            area = cv2.contourArea(cnt[i])
            if(area>10000 and area<100000):
                  mask = np.zeros_like(img)
                  cv2.drawContours(mask, cnt, i, 255, -1)
                  x,y,w,h = cv2.boundingRect(cnt[i])
                  crop= img[ y:h+y,x:w+x]
                  cv2.imshow("snip",crop )
                  if(cv2.waitKey(0))==27:break

cv2.destroyAllWindows()

This is the result. It only crops the smaller box. What I want is for it to crop the two squares.

sampled crop

JonathanDavidArndt
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Crispolo Bernardino
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    your 'area<100000' it is too small for the big rectangle, your image is 960x720 and this covers like 50% of it, that is at least 345000... i would suggest to put even bigger or remove it – api55 Mar 07 '18 at 06:27
  • thank you for that tip it work as i used trial and error method changing the size.. but i have this one problem again. it don't crop perfectly as i wanted can you help me with that too? sampled crop is attach and it does not crop perfectly. i'm working with this transform method and warp but i'm just a beginner so i'ts hard for me. thanks you i'll appreciate it – Crispolo Bernardino Mar 08 '18 at 12:46

1 Answers1

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if you have the coordinates of the rectangles you can try:

cropped = img [y1:y2, x1:x2]

cv2.imwrite('cropped.png', cropped)

The first line crops the image base on the given coordinates assuming (y1

mpour
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  • thanks on your response but the coordinates changes as i change the picture because i'm working in cropping by the pattern and that pattern is the square box in the image. unfortunately I can't use the coordinate cropping because as i use the code to different image the coordinate of the box is changes because i don't have a fixed coordinate with the different images. – Crispolo Bernardino Mar 08 '18 at 12:38