def rotateImage(self):
        ForwardMap = np.zeros((self.width,self.height),dtype="uint8")
        BackwardMap = np.zeros((self.width,self.height),dtype="uint8")

        for i in range(self.width):
            for j in range(self.height):
                # forward mapping
                for_x = (i - self.x) * math.cos(self.angle*(math.pi/180)) - (j - self.y) * math.sin(self.angle*(math.pi/180)) + self.x
                for_y = (i - self.x) * math.sin(self.angle*(math.pi/180)) + (j - self.y) * math.cos(self.angle*(math.pi/180)) + self.x
                for_x = int(for_x)
                for_y = int(for_y)
                # backward mapping
                back_x = (i - self.x) * math.cos(self.angle*(math.pi/180)) + (j - self.y) * math.sin(self.angle*(math.pi/180)) + self.x
                back_y = -(i - self.x) * math.sin(self.angle*(math.pi/180)) + (j - self.y) * math.cos(self.angle*(math.pi/180)) + self.x
                back_x = int(back_x)
                back_y = int(back_y)
                if for_x in range(self.width) and for_y in range(self.height):
                    ForwardMap[i, j] = self.img[for_x, for_y]
                else:
                    pass
                if back_x in range(self.width) and back_y in range(self.height):
                    BackwardMap[i, j] = self.img[back_x, back_y]
                else:
                    pass
        cv2.imshow('Forward Mapping', ForwardMap)
        cv2.imshow('Backward Mapping', BackwardMap)