import cv2
import numpy as np


cnt=0
list=[(0,0),(0,0),(0,0),(0,0)]

# mouse callback function
def draw_circle(event,x,y,flags,param):
    if event == cv2.EVENT_LBUTTONUP:
        global list, cnt
        if cnt ==4:
            cnt=0
        cv2.circle(img_resized, (x, y), 1, (0, 255, 0), -1)
        list[cnt]=(x,y)
        cnt+=1


img = cv2.imread('road.jpg')
height, width=img.shape[:2]
# resize
img_resized=cv2.resize(img,None, fx=0.4,fy=0.4,interpolation=cv2.INTER_AREA)
result=img_resized.copy()


# mouse function
cv2.namedWindow('before')
cv2.setMouseCallback('before',draw_circle)

# height & width
h,w=img_resized.shape[:2]

# before

while(1):

    cv2.imshow('before', img_resized)

    if cnt==4:
        print(list)
        pts1 = np.float32([list[0], list[1], list[2], list[3]])
        pts2 = np.float32([[0, 0], [w, 0], [0, h], [w, h]])
        M = cv2.getPerspectiveTransform(pts1, pts2)
        dst = cv2.warpPerspective(result, M, (w, h))
        cv2.imshow('after', dst)
        #zeby te kropki zielone zniknely
        img_resized=result.copy()

    if cv2.waitKey(20) & 0xFF == 27:
        break
cv2.destroyAllWindows()