Python:マウスコールバック関数

Python:マウスコールバック関数

1. マウスコールバック関数拡大縮小画像

1.マウスコールバック関数による画像の拡大・縮小

import cv2


class Param:
    def __init__(self, img):
        self.img = img
        self.scale = 0.8
        self.src = cv2.resize(img,
                              (int(img.shape[1] * self.scale), int(img.shape[0] * self.scale)),
                              cv2.INTER_AREA)

    def lbuttondown(self, x, y):
        self.lmove_from = (x, y)
        print("-lbuttondown>", round(x / self.scale), round(y / self.scale))

    def rbuttondown(self):
        print("->rbuttondown")

    def mousewheel(self, flags):
        self.scale += flags / abs(flags) / 50
        if self.scale < 0.5:
            self.scale = 0.5
        elif self.scale > 2:
            self.scale = 2
        w = int(self.img.shape[1] * self.scale)
        h = int(self.img.shape[0] * self.scale)
        #       ，          
        self.src = cv2.resize(self.img, (w, h), cv2.INTER_AREA)
        #if w < int(img.shape[1]):
            #cv2.resizeWindow('ABC', w, h)
        #     (self.src.shape[1], self.src.shape[0])      (self.img.shape[1], self.img.shape[0])
        else:
            src_cropped = self.src[0 : self.img.shape[1], 0 : self.img.shape[0]]
            cv2.imshow('ABC', src_cropped)

    def flag_lbutton(self, x, y):
        pass
        self.lmove_to = (x, y)
        move_vector = tuple(map(lambda x: x[0]-x[1], zip(self.lmove_to, self.lmove_from)))
        right_boundary = self.src.shape[1] - move_vector[1]
        top_boundary = self.src.shape[0] - move_vector[0]
        if right_boundary < 0:
            right_boundary = 0
        elif right_boundary > self.src.shape[1] - self.img.shape[1]:
            right_boundary = self.src.shape[1] - self.img.shape[1]
        if top_boundary < 0:
            top_boundary = 0
        elif top_boundary > self.src.shape[0] - self.img.shape[0]:
            top_boundary = self.src.shape[0] - self.img.shape[0]
        src_moved = self.src[right_boundary : (right_boundary + self.img.shape[1]),
                             top_boundary : (top_boundary + self.img.shape[0])]
        print("->flag_lbutton:", move_vector)
        cv2.imshow('ABC', src_moved)


def mouse(event, x, y, flags, param):
    if event == cv2.EVENT_LBUTTONDOWN:
        param.lbuttondown(x, y)
    elif event == cv2.EVENT_RBUTTONDOWN:
        param.rbuttondown()
    elif event == cv2.EVENT_MOUSEWHEEL:
        param.mousewheel(flags)
    elif flags == cv2.EVENT_FLAG_LBUTTON:
        param.flag_lbutton(x, y)
    

if __name__ == '__main__':
    img = cv2.imread('1.jpg')
    param = Param(img)
    cv2.namedWindow('ABC', cv2.WINDOW_NORMAL)
    cv2.setMouseCallback('ABC', mouse, param)
    #cv2.imshow('ABC', param.src)
    cv2.waitKey(0)
    cv2.destroyAllWindows()