python 에서 mouse click 하여 image 상 영역 선택하는 함수

참조: http://stackoverflow.com/questions/23596511/how-to-save-mouse-position-in-variable-using-opencv-and-python
참조: http://www.pyimagesearch.com/2015/03/09/capturing-mouse-click-events-with-python-and-opencv/

위 두 참조의 코드를 조합하여 만듬.

함수

class MouseControl:
    def __init__(self):
        # self.points = []        self.refPt = []
        self.cropping = False        self.retRect = []

    # def getPoint(self, event, x, y, flags, params):    #     if event == cv2.EVENT_LBUTTONCLK:    #         self.points = [x, y]
    def click_and_crop(self, event, x, y, flags, param):
        if event == cv2.EVENT_LBUTTONDOWN:
            self.refPt = [(x, y)]
            self.cropping = True
        elif event == cv2.EVENT_LBUTTONUP:
            self.refPt.append((x, y))
            self.cropping = False
            #   left, top, right, bottom            self.retRect = [mousectrl.refPt[0][1], mousectrl.refPt[0][0], mousectrl.refPt[1][1], mousectrl.refPt[1][0]]
            self.refPt = []

        return self.retRect

실제사용

# if mouse has an input,cv2.namedWindow('img1')
cv2.setMouseCallback('img1', mousectrl.click_and_crop)

# for t in range(2):while(1):
    cv2.imshow('img1', img1)
    k = cv2.waitKey(20) & 0xFF    # print mousectrl.refPt    if k == ord('n'):
        break    if len(mousectrl.retRect) == 4:
        break
mousectrl.retRect[0] << left
mousectrl.retRect[2] << right
mousectrl.retRect[1] << top
mousectrl.retRect[3] << bottom

mousectrl.retRect = []