想把彩色图像灰度化，但是RGB三通道灰度化之后，shape少了一维，feed_dic shape维数不匹配了
Traceback (most recent call last):
File "trainModel.py", line 75, in
kernel_initializer=tf.glorot_normal_initializer())
File "/usr/lib/python2.7/site-packages/tensorflow/python/layers/convolutional.py", line 608, in conv2d
return layer.apply(inputs)
File "/usr/lib/python2.7/site-packages/tensorflow/python/layers/base.py", line 671, in apply
return self.__call__(inputs, *args, **kwargs)
File "/usr/lib/python2.7/site-packages/tensorflow/python/layers/base.py", line 550, in call
self._assert_input_compatibility(inputs)
File "/usr/lib/python2.7/site-packages/tensorflow/python/layers/base.py", line 1044, in _assert_input_compatibility
str(x.get_shape().as_list()))
ValueError: Input 0 of layer conv2d_1 is incompatible with the layer: expected ndim=4, found ndim=3. Full shape received: [None, 100, 100]
似乎是因为灰度化操作之后读取的图片数据的通道那一维就没了，有没有办法解决啊，新手不是很懂
