我运行了官方网站提供的示例cifar10_train.py，但在行summary_str=sess.run(summary_op)中出现错误：
Tensor must be 4-D with last dim 1, 3, or 4, not []
[[Node: conv1/conv1/conv1/sparsity = ImageSummary[T=DT_FLOAT, bad_color=Tensor<type: uint8 shape: [4] values: 255 0 0...>, max_images=3, _device="/job:localhost/replica:0/task:0/device:CPU:0"](conv1/conv1/conv1/sparsity/tag, conv1/zero_fraction/Mean/_251)]]
[[Node: conv2/conv2-2-1-TransposeNCHWToNHWC-LayoutOptimizer/_240 = _Send[T=DT_FLOAT, client_terminated=false, recv_device="/job:localhost/replica:0/task:0/device:CPU:0", send_device="/job:localhost/replica:0/task:0/device:GPU:0", send_device_incarnation=1, tensor_name="edge_322_conv2/conv2-2-1-TransposeNCHWToNHWC-LayoutOptimizer", _device="/job:localhost/replica:0/task:0/device:GPU:0"](conv2/conv2-2-1-TransposeNCHWToNHWC-LayoutOptimizer)]]
我不知道。你能帮我吗？