Can anyone please explain image pixel coordinate plane?

3

Here is the full code. so what this code does is it will open an imagewindow and when we left click anywhere in the image it will show the point where we leftclicked and its coordinate. I hope this helps

import cv2
import numpy as np

counter = 0
points = []
def MouseCallback(event, x, y, flags, userdata):
    global counter
    if(event == cv2.EVENT_LBUTTONDOWN):
        if(counter < 4):
            cv2.circle(dst, (x,y), 3, (0,255,255), 4, cv2.LINE_AA)
            cv2.putText(dst, "x: {x},y:{y}".format(x=x,y=y), (x-250,y), cv2.FONT_HERSHEY_SIMPLEX, 1,(0,100,255),2,cv2.LINE_AA)
            cv2.imshow("Destination Image", dst)
            points.append((x,y))
            counter += 1
            #print(x,y)
            #print(points)
        if(len(points) == 4):
            #roi = dst[:,541:1018]
            #cv2.imshow("winname", roi)
            #print(points)
            array_points = np.array(points)
            #new_points = order_points(array_points)
            print(array_points)
            cv2.imwrite("saved.jpg", dst)
            #top_left_x = min(points, key=itemgetter(1))[0]
            #top_left_y = min(points, key=itemgetter(0))[0]
            #bot_right_x = max(points, key=itemgetter(1))[0]
            #bot_right_y = max(points, key=itemgetter(0))[0]
            
            #height = top_left_y - bot_right_y
            #width = top_left_x - bot_right_x
            #print(y1,x1,y2,x2)
            #roi = dst[top_left_y:bot_right_y+1,top_left_x:bot_right_x+1]
            #cv2.imshow("roi", roi)
dst = cv2.imread("times_square.jpg")
mask = np.zeros((dst.shape[:2]),dtype='uint8')
cv2.imshow("mask", mask)
cv2.imshow("Destination Image", dst)
print(cv2.EVENT_RBUTTONDOWN,"hello")
cv2.setMouseCallback("Destination Image", MouseCallback)
key = cv2.waitKey(0)
if( key == ord('q') ):
    cv2.destroyAllWindows()