augmentation.py 文件源码

def rotate_bboxes(image, obj_list, angle):
        '''
        Rotates the bounding boxes of the given objects by the given angle. The bounding box will be
        translated into absolute coordinates. Therefore the image (resp. its shape) is needed.
        '''

        rotated_obj_list = []
        cosOfAngle = np.cos(2 * np.pi / 360 * -angle)
        sinOfAngle = np.sin(2 * np.pi / 360 * -angle)
        image_shape = np.array(np.atleast_3d(image).shape[0:2][::-1])
        rot_mat = np.array([[cosOfAngle, -sinOfAngle], [sinOfAngle, cosOfAngle]])
        for obj in obj_list:
            obj_name = obj[0]
            upper_left = obj[1]['upper_left'] * image_shape
            lower_right = obj[1]['lower_right'] * image_shape
            upper_left = AugmentationCreator._rotate_vector_around_point(image_shape/2, upper_left, rot_mat) / image_shape
            lower_right = AugmentationCreator._rotate_vector_around_point(image_shape/2, lower_right, rot_mat) / image_shape
            rotated_obj_list.append((obj_name, {'upper_left' : upper_left, 'lower_right' : lower_right}))

        return rotated_obj_list