Extract all bounding boxes using OpenCV Python

问题

I have an image that contains more than one bounding box.

I need to extract everything that has bounding boxes in them. So far, from this site I've gotten this answer:

y = img[by:by+bh, bx:bx+bw]
cv2.imwrite(string + '.png', y)

It works, however, it only gets one. How should I modify the code? I tried putting it in the loop for contours but it still spews out one image instead of multiple ones.

Thank you so much in advance.

回答1:

there you go:

import cv2

im = cv2.imread('c:/data/ph.jpg')
gray=cv2.cvtColor(im,cv2.COLOR_BGR2GRAY)
contours, hierarchy = cv2.findContours(gray,cv2.RETR_LIST,cv2.CHAIN_APPROX_SIMPLE)[-2:]
idx =0 
for cnt in contours:
    idx += 1
    x,y,w,h = cv2.boundingRect(cnt)
    roi=im[y:y+h,x:x+w]
    cv2.imwrite(str(idx) + '.jpg', roi)
    #cv2.rectangle(im,(x,y),(x+w,y+h),(200,0,0),2)
cv2.imshow('img',im)
cv2.waitKey(0)    

来源：https://stackoverflow.com/questions/21104664/extract-all-bounding-boxes-using-opencv-python