Extract picture from picture

Python
1

I want to extract picture from picture
from below link I come up my code

import cv2

image = cv2.imread('/home/joy/桌面/test_11_2/split_img/original.png', cv2.IMREAD_UNCHANGED)

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

kernel = cv2.getStructuringElement(cv2.MORPH_RECT, (5,5))
gradient = cv2.morphologyEx(gray, cv2.MORPH_GRADIENT, kernel)

contours = cv2.findContours(gradient, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)[1]

for cnt in contours:
    (x,y,w,h) = cv2.boundingRect(cnt)
    cv2.rectangle(image, (x,y), (x+w,y+h), (0,0,255))
    yyy = cv2.rectangle(image, (x,y), (x+w,y+h), (0,0,255))
    
    
cv2.imshow("output", yyy)
cv2.imwrite("/home/joy/桌面/test_11_2/split_img/yyy.png", yyy)

but looks like below

I want to extract each sticker 5x6 and to total 30 sticker
like below , how do I do so
螢幕快照 2022-11-03 15-37-32
(without gray part is fine)

2

I’m trying to extract pictures from an big image in python

Environment: Python 3.9.12 with CV2 4.6.0 on Ubuntu 22.04.1 LTS

I faced cv2.error :‘pointSetBoundingRect’

import cv2

image = cv2.imread('/home/joy/桌面/test_11_2/split_img/original.png', cv2.IMREAD_UNCHANGED)

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

kernel = cv2.getStructuringElement(cv2.MORPH_RECT, (5,5))
gradient = cv2.morphologyEx(gray, cv2.MORPH_GRADIENT, kernel)

contours = cv2.findContours(gradient, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)[1]

for cnt in contours:
    (x,y,w,h) = cv2.boundingRect(cnt)
    cv2.rectangle(image, (x,y), (x+w,y+h), (0,0,255))
    
cv2.imwrite("/home/joy/桌面/test_11_2/split_img/original.png", contours)
cv2.imshow("output", contours)
  • the error:
Traceback (most recent call last):
  File "/home/joy/桌面/test_11_2/split_img/split_image.py", line 14, in <module>
    (x,y,w,h) = cv2.boundingRect(cnt)
cv2.error: OpenCV(4.6.0) /io/opencv/modules/imgproc/src/shapedescr.cpp:874: error: (-215:Assertion failed) npoints >= 0 && (depth == CV_32F || depth == CV_32S) in function 'pointSetBoundingRect'

I tried to solved by this link
python - OpenCV Assertion failed: (-215:Assertion failed) npoints >= 0 && (depth == CV_32F || depth == CV_32S) - Stack Overflow

using _, contours, _ = cv2.findContours(img,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_NONE) and other way still not work

(base) joy@joy-System-Product-Name:~/桌面/test_11_2/split_img$ python split_image.py
Traceback (most recent call last):
  File "/home/joy/桌面/test_11_2/split_img/split_image.py", line 14, in <module>
    (x,y,w,h) = cv2.boundingRect(cnt)
cv2.error: OpenCV(4.6.0) /io/opencv/modules/imgproc/src/shapedescr.cpp:874: error: (-215:Assertion failed) npoints >= 0 && (depth == CV_32F || depth == CV_32S) in function 'pointSetBoundingRect'

(base) joy@joy-System-Product-Name:~/桌面/test_11_2/split_img$ python split_image.py
Traceback (most recent call last):
  File "/home/joy/桌面/test_11_2/split_img/split_image.py", line 11, in <module>
    _ , contours = cv2.findContours(gradient, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)[1]
ValueError: not enough values to unpack (expected 2, got 1)

Therefor, I try as far as I could, pls give me a hand

3

duplicate of Extract picture from picture

(@ton02_j , please dont do this, and stick to a single account on this site, thank you)

4

please, take the tutorials tour, instead of blindly copypasting (outdated bs) from SO.