Get the coordinates of any screenshot with PyScreeze and OpenCV.

cv_region_crop.py

import cv2 as cv

from numpy import asarray, ndarray
from pyscreeze import screenshot

IntVector2 = tuple[int, int]


class NoRegionSelected(Exception):
    """Raised when the user ends the selection without selecting a region."""


class RegionOfInterest:

    def __init__(self, screen: ndarray, window_name: str):
        
        self.original_screen = screen
        self.screen = screen.copy()
        self.window_name = window_name
        
        self.colour = (0, 255, 0)
        self.thickness = 1
        
        self.bounds = []
        self.hold = False
        

    def get_region_bounds(self) -> tuple[IntVector2, IntVector2]:
        
        if not self.bounds:
            raise NoRegionSelected('No region has been selected.')

        unsorted_bounds          = asarray(self.bounds, dtype=object).T
        top_left_coordinates     = (unsorted_bounds[0].min(), unsorted_bounds[1].min())
        bottom_right_coordinates = (unsorted_bounds[0].max(), unsorted_bounds[1].max())

        return top_left_coordinates, bottom_right_coordinates


    def select_region_of_interest(self, event, x: int, y: int, *args):

        if event == cv.EVENT_LBUTTONDOWN:
            self.hold = True
            self.screen = self.original_screen.copy()
            self.bounds.clear()
            self.bounds.append([x, y])

        elif event == cv.EVENT_MOUSEMOVE and self.hold:
            self.screen = self.original_screen.copy()
            cv.rectangle(self.screen, self.bounds[0], (x, y), self.colour, self.thickness)
            cv.imshow(self.window_name, self.screen)

        elif event == cv.EVENT_LBUTTONUP:
            self.hold = False
            self.bounds.append([x, y])
            cv.rectangle(self.screen, self.bounds[0], self.bounds[1], self.colour, self.thickness)
            cv.imshow(self.window_name, self.screen)


def cv_region_crop(window_name: str) -> tuple[IntVector2, IntVector2]:
    
    screen = cv.cvtColor(asarray(screenshot()), cv.COLOR_RGB2BGR)
    roi = RegionOfInterest(screen, window_name)
    
    cv.namedWindow(window_name, cv.WINDOW_GUI_NORMAL)
    cv.setMouseCallback(window_name, roi.select_region_of_interest)
    cv.imshow(window_name, screen)

    while True:
        key = cv.waitKey(1)

        if key == ord('q'):
            break

        if cv.getWindowProperty(window_name, cv.WND_PROP_VISIBLE) < 1:
            break

    return roi.get_region_bounds()


def region_crop(window_name: str) -> tuple[IntVector2, IntVector2]:

    region = cv_region_crop(window_name)
    cv.destroyWindow(window_name)

    return region