how to find the points of the contour parts of the images using opencv python?

Asked May 12 '21 at 14:01

Active May 12 '21 at 16:56

Viewed 224 times

I am trying to find the points of the contours parts(4 points) of the images (not related to the width and height of whole images).input image point are (0,0) (1300,0), (1800,0), and (1300,1800) and output image ( 0,0),(1300,0),(1600,0),(1300,1600) . My expected output should be for the bottom-left (100,1630) that mean x will be start from 130.
my code is :

      contours, hierarcy=cv2.findContours(thresh_img, cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)
      cv2.drawContours(original_img, contours, -1, (255,120,0), 2, cv2.LINE_AA)
      max_contours=max(contours, key=cv2.contourArea)
      x,y,w,g=cv2.boundingRect(max_contours)
      cv2.rectangle(original_img, (x,y), (x+w, y+h),(0.255,0),5)
      cropped_image1=original_img[y:y+h, x:x+w]
      plt.imshow(cropped_image1)

How to get this type of points of the images.I have used the getperspective transform (4 points transform )I do not get the expected result. Please tell me how to do ? Thanks....

edited May 12 '21 at 16:56

asked May 12 '21 at 14:01

Amit Saini

Generally the external contour can be reduced to it 4 points using cv2.approxPolyDP(). But your page is cropped and does not show the top left corner of the page. So you will have 5 points here. – fmw42 May 12 '21 at 15:44
Thanks for the comments , I am trying to solve that. – Amit Saini May 12 '21 at 16:56
Do you have an example that shows all 4 corners? If so, please post that. – fmw42 May 12 '21 at 17:47
I have no such example that show 4 corners of the images. – Amit Saini May 13 '21 at 04:33
You need 4 corresponding sets of points to do perspective warp. So you need the proper corners. – fmw42 May 13 '21 at 04:36
Okay . Thanks you.... – Amit Saini May 13 '21 at 09:17

how to find the points of the contour parts of the images using opencv python?

0 Answers0