cv_view.py

#-*- coding: utf-8 -*-

import cv2
from collections import defaultdict


class ImageFlip(object):
    def __init__(self):
        self._observers = []

    def attach(self, observer):
        if not observer in self._observers:
            self._observers.append(observer)

    def detach(self, observer):
        self._observers.remove(observer)

    def notify(self, modifier=None):
        for observer in self._observers:
            if modifier != observer:
                observer.update(self)


class CvImageFlip(ImageFlip):
    def __init__(self, flip_code):
        ImageFlip.__init__(self)
        self._flip_code = flip_code

    @property
    def img(self):
        return self._img

    @img.setter
    def img(self, image_file):
        self._img = cv2.imread(image_file)
        self.notify()

    def execute(self):
        self._img = cv2.flip(self._img, self._flip_code)
        self.notify()


class CvViewer:
    def __init__(self, window_name):
        self._window_name = window_name

    def update(self, subject):
        cv2.imshow(self._window_name, subject._img)

    def close(self, subject):
        cv2.destroyWindow(self._window_name)


### Key Definition
UP_KEY = 63232
DOWN_KEY = 63233
LEFT_KEY = 63234
RIGHT_KEY = 63235
ESC_KEY = 27

### Flip Definition
FLIP_Y = 1
FLIP_X = 0


def main():
    img1 = CvImageFlip(FLIP_Y)
    view1 = CvViewer('TEST')
    img1.attach(view1)
    img1.img = 'test.jpg'

    img2 = CvImageFlip(FLIP_X)
    view2 = CvViewer('TEST2')
    img2.attach(view2)
    img2.img = 'test2.jpg'

    while True:
        key = cv2.waitKey(33)
        if key == UP_KEY or key == DOWN_KEY:
            img1.execute()
        elif key == LEFT_KEY or key == RIGHT_KEY:
            img2.execute()
        elif key == ESC_KEY:
            break

if __name__ == '__main__':
    main()