left_image.set_shape([None, None, 3])
left_label.set_shape([None, None, 1])    
self.offset_height = np.random.randint(self.params.height -   self.params.patch_height)
self.offset_width = np.random.randint(self.params.width - self.params.patch_width)
# self.offset_height = 256
# self.offset_width = 320
target_height = self.params.patch_height
target_width = self.params.patch_width
crops = tf.image.crop_to_bounding_box(tf.concat([left_image, left_label], -1),self.offset_height, self.offset_width, target_height, target_width)

# crops = tf.random_crop(tf.concat([left_image, right_image, left_label, right_label], -1), [self.params.patch_height, self.params.patch_width, 8])
left_image, left_label = tf.split(crops, [3, 1], axis=2)