Add mean IOU op. (#10519)

* Add mean_iou op.

* Add unitest for mean iou op.

* Add optional collections of confusion matrix and mean_iou.

* Fix cuda kernel.

* Refine code.
1. Merge computing in GPU to two kernel.
2. Use wrong array and correct array instead of confusion matrix.

* Add python api and fix cuda kernel.

* Fix comments.

* Small fix.

* Small fix.

paddle/fluid/operators/mean_iou_op.cc

+/* Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License. */
+
+#include "paddle/fluid/operators/mean_iou_op.h"
+
+namespace paddle {
+namespace operators {
+
+class MeanIoUOp : public framework::OperatorWithKernel {
+ public:
+  using framework::OperatorWithKernel::OperatorWithKernel;
+
+  void InferShape(framework::InferShapeContext* ctx) const override {
+    PADDLE_ENFORCE(ctx->HasInput("Predictions"),
+                   "Input (Predictions) of MeanIoU op should not be null.");
+    PADDLE_ENFORCE(ctx->HasInput("Labels"),
+                   "Input (labels) of MeanIoU op should not be null.");
+    PADDLE_ENFORCE(ctx->HasOutput("OutMeanIou"),
+                   "Output (OutMeanIou) of MeanIoU op should not be null.");
+    PADDLE_ENFORCE(ctx->HasOutput("OutWrong"),
+                   "Output (OutWrong) of MeanIoU op should not be null.");
+    PADDLE_ENFORCE(ctx->HasOutput("OutCorrect"),
+                   "Output (OutWrong) of MeanIoU op should not be null.");
+
+    int64_t num_classes =
+        static_cast<int64_t>(ctx->Attrs().Get<int>("num_classes"));
+
+    ctx->SetOutputDim("OutMeanIou", {1});
+    ctx->SetOutputDim("OutWrong", {num_classes});
+    ctx->SetOutputDim("OutCorrect", {num_classes});
+  }
+
+ protected:
+  framework::OpKernelType GetExpectedKernelType(
+      const framework::ExecutionContext& ctx) const override {
+    return framework::OpKernelType(
+        framework::ToDataType(ctx.Input<Tensor>("Predictions")->type()),
+        ctx.GetPlace());
+  }
+};
+
+class MeanIoUOpMaker : public framework::OpProtoAndCheckerMaker {
+ public:
+  void Make() override {
+    AddInput("Predictions",
+             "(Tensor), A Tensor of prediction results for semantic labels"
+             " with type int32 or int64. The rank should be greater than 1.");
+    AddInput(
+        "Labels",
+        "(Tensor), A Tensor of ground truth labels with type int32 or int64."
+        "Its shape should be the same as Input(Predictions).");
+    AddInput("InWrongs",
+             "(vector<Tensor>), A list of Tensor with shape "
+             "[num_classes]. They are used to collect wrong number among "
+             "batches. Empty list is also valid here.")
+        .AsDuplicable()
+        .AsDispensable();
+    AddInput(
+        "InCorrects",
+        "(vector<Tensor>), A list of Tensor with shape "
+        "[num_classes]. They are used to collect correct number among batches. "
+        "Empty list is also valid here.")
+        .AsDuplicable()
+        .AsDispensable();
+    AddInput("InMeanIou",
+             "(vector<Tensor>), A list of Tensor that Output(mean_iou) should "
+             "be added to. Empty list is also valid here.")
+        .AsDuplicable()
+        .AsDispensable();
+    AddOutput("OutMeanIou",
+              "(vector<Tensor>), A Tensor representing the"
+              " mean intersection-over-union with shape [1].");
+    AddOutput("OutWrong", "(Tensor), A Tensor with shape [num_classes]. ");
+    AddOutput("OutCorrect", "(Tensor), A Tensor with shape [num_classes]. ");
+    AddAttr<int>("num_classes", "(int), The possible number of labels.");
+
+    AddComment(R"DOC(
+mean-IOU Operator.
+Mean Intersection-Over-Union is a common evaluation metric for
+semantic image segmentation, which first computes the IOU for each
+semantic class and then computes the average over classes. 
+IOU is defined as follows: 
+    IOU = true_positive / (true_positive + false_positive + false_negative).
+It is based on pixel level area while "IOU Similarity Operator" 
+is based on area of rectangle.
+
+)DOC");
+  }
+};
+
+}  // namespace operators
+}  // namespace paddle
+
+namespace ops = paddle::operators;
+REGISTER_OPERATOR(mean_iou, ops::MeanIoUOp, ops::MeanIoUOpMaker,
+                  paddle::framework::EmptyGradOpMaker);
+REGISTER_OP_CPU_KERNEL(mean_iou, ops::MeanIoUKernel<int>,
+                       ops::MeanIoUKernel<int32_t>,
+                       ops::MeanIoUKernel<int64_t>);

paddle/fluid/operators/mean_iou_op.cu

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License. */
+
+#include "paddle/fluid/operators/math/math_function.h"
+#include "paddle/fluid/operators/mean_iou_op.h"
+#include "paddle/fluid/platform/cuda_primitives.h"
+#include "paddle/fluid/platform/gpu_info.h"
+
+namespace paddle {
+namespace operators {
+
+using platform::PADDLE_CUDA_NUM_THREADS;
+
+#define CUDA_1D_KERNEL_LOOP(i, n)                              \
+  for (int i = blockIdx.x * blockDim.x + threadIdx.x; i < (n); \
+       i += blockDim.x * gridDim.x)
+
+template <typename T>
+__global__ void CountCUDAKernel(const int num_classes, const int count,
+                                const T* predictions, const T* labels,
+                                int* wrong, int* correct) {
+  extern __shared__ int blcok_cache[];
+  int* wrong_c = blcok_cache;
+  int* correct_c = blcok_cache + num_classes;
+  // init cache
+  for (int i = threadIdx.x; i < num_classes * 2; i += blockDim.x) {
+    blcok_cache[i] = 0;
+  }
+  __syncthreads();
+
+  T pred;
+  T label;
+  CUDA_1D_KERNEL_LOOP(i, count) {
+    pred = predictions[i];
+    label = labels[i];
+    if (pred == label) {
+      atomicAdd(correct_c + pred, 1);
+    } else {
+      atomicAdd(wrong_c + pred, 1);
+      atomicAdd(wrong_c + label, 1);
+    }
+  }
+
+  __syncthreads();
+
+  for (int i = threadIdx.x; i < num_classes; i += blockDim.x) {
+    atomicAdd(wrong + i, wrong_c[i]);
+    atomicAdd(correct + i, correct_c[i]);
+  }
+}
+
+__global__ void ComputeIoUCUDAKernel(const int num_classes, int* wrong,
+                                     int* correct, float* ious, float* iou) {
+  __shared__ int valid_count_c;
+  if (threadIdx.x == 0) {
+    valid_count_c = 0;
+  }
+  __syncthreads();
+  CUDA_1D_KERNEL_LOOP(i, num_classes) {
+    int wrong_n = wrong[i];
+    int correct_n = correct[i];
+    int denominator = wrong_n + correct_n;
+    if (denominator > 0) {
+      atomicAdd(&valid_count_c, 1);
+      ious[i] = static_cast<float>(correct_n) / denominator;
+    } else {
+      ious[i] = 0;
+    }
+  }
+  __syncthreads();
+  if (threadIdx.x == 0) {
+    float iou_sum = 0;
+    for (int i = 0; i < num_classes; ++i) {
+      iou_sum += ious[i];
+    }
+    iou[0] += iou_sum / valid_count_c;
+  }
+}
+
+template <typename T>
+class MeanIoUCUDAOpKernel : public framework::OpKernel<T> {
+ public:
+  void Compute(const framework::ExecutionContext& ctx) const override {
+    auto& place = *ctx.template device_context<platform::CUDADeviceContext>()
+                       .eigen_device();
+    // get input and output tensor
+    auto* predictions = ctx.Input<Tensor>("Predictions");
+    auto* labels = ctx.Input<Tensor>("Labels");
+    auto* out_mean_iou = ctx.Output<Tensor>("OutMeanIou");
+    auto* out_wrong = ctx.Output<Tensor>("OutWrong");
+    auto* out_correct = ctx.Output<Tensor>("OutCorrect");
+    int num_classes = static_cast<int>(ctx.Attr<int>("num_classes"));
+
+    // Get data ptr
+    const T* predictions_data = predictions->data<T>();
+    const T* labels_data = labels->data<T>();
+    int* out_wrong_data = out_wrong->mutable_data<int>(ctx.GetPlace());
+    int* out_correct_data = out_correct->mutable_data<int>(ctx.GetPlace());
+    float* out_mean_iou_data =
+        out_mean_iou->mutable_data<float>(ctx.GetPlace());
+
+    // Get Eigen tensor
+    auto out_mean_iou_t = EigenTensor<float, 1>::From(*out_mean_iou);
+    auto out_wrong_t = EigenTensor<int, 1>::From(*out_wrong);
+    auto out_correct_t = EigenTensor<int, 1>::From(*out_correct);
+
+    // Temporary tensor
+    Tensor ious;
+    float* ious_data = ious.mutable_data<float>(
+        {static_cast<int64_t>(num_classes)}, ctx.GetPlace());
+    auto ious_t = EigenTensor<float, 1>::From(ious);
+
+    // Init out_wrong, out_correct and out_mean_iou
+    out_wrong_t.device(place) = out_wrong_t.constant(0);
+    out_correct_t.device(place) = out_correct_t.constant(0);
+    out_mean_iou_t.device(place) = out_mean_iou_t.constant(0.0f);
+
+    // collect pre wrong, correct and mean_iou
+    auto in_mean_ious = ctx.MultiInput<Tensor>("InMeanIou");
+    for (int i = 0; i < in_mean_ious.size(); ++i) {
+      out_mean_iou_t.device(place) +=
+          EigenTensor<float, 1>::From(*in_mean_ious[i]);
+    }
+    auto in_wrongs = ctx.MultiInput<Tensor>("InWrongs");
+    for (int i = 0; i < in_wrongs.size(); ++i) {
+      out_wrong_t.device(place) += EigenTensor<int, 1>::From(*in_wrongs[i]);
+    }
+    auto in_corrects = ctx.MultiInput<Tensor>("InCorrects");
+    for (int i = 0; i < in_corrects.size(); ++i) {
+      out_correct_t.device(place) += EigenTensor<int, 1>::From(*in_corrects[i]);
+    }
+    // compute
+    auto stream = ctx.cuda_device_context().stream();
+    int block = PADDLE_CUDA_NUM_THREADS;
+    int grid = (predictions->numel() + block - 1) / block;
+    int cache_size = (num_classes * 2 + 1) * sizeof(int);
+    CountCUDAKernel<T><<<grid, block, cache_size, stream>>>(
+        num_classes, predictions->numel(), predictions_data, labels_data,
+        out_wrong_data, out_correct_data);
+    ctx.device_context().Wait();
+    ComputeIoUCUDAKernel<<<1, block, 0, stream>>>(num_classes, out_wrong_data,
+                                                  out_correct_data, ious_data,
+                                                  out_mean_iou_data);
+  }
+};
+
+}  // namespace operators
+}  // namespace paddle
+
+namespace ops = paddle::operators;
+REGISTER_OP_CUDA_KERNEL(mean_iou, ops::MeanIoUCUDAOpKernel<int>,
+                        ops::MeanIoUCUDAOpKernel<int64_t>,
+                        ops::MeanIoUCUDAOpKernel<int32_t>);

paddle/fluid/operators/mean_iou_op.h

+/* Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License. */
+
+#pragma once
+#include <algorithm>
+#include "paddle/fluid/framework/op_registry.h"
+
+namespace paddle {
+namespace operators {
+using Tensor = framework::Tensor;
+
+template <typename T, int D, int MajorType = Eigen::RowMajor,
+          typename IndexType = Eigen::DenseIndex>
+using EigenTensor = framework::EigenTensor<T, D, MajorType, IndexType>;
+
+template <typename T>
+class MeanIoUKernel : public framework::OpKernel<T> {
+ public:
+  void Compute(const framework::ExecutionContext& ctx) const override {
+    auto& place = *ctx.template device_context<platform::CPUDeviceContext>()
+                       .eigen_device();
+    // get input and output tensor
+    auto* predictions = ctx.Input<Tensor>("Predictions");
+    auto* labels = ctx.Input<Tensor>("Labels");
+    auto* out_mean_iou = ctx.Output<Tensor>("OutMeanIou");
+    auto* out_wrong = ctx.Output<Tensor>("OutWrong");
+    auto* out_correct = ctx.Output<Tensor>("OutCorrect");
+    int num_classes = static_cast<int>(ctx.Attr<int>("num_classes"));
+
+    // get data ptr
+    const T* predictions_data = predictions->data<T>();
+    const T* labels_data = labels->data<T>();
+    float* out_mean_iou_data =
+        out_mean_iou->mutable_data<float>(ctx.GetPlace());
+    int* out_wrong_data = out_wrong->mutable_data<int>(ctx.GetPlace());
+    int* out_correct_data = out_correct->mutable_data<int>(ctx.GetPlace());
+
+    // get eigen tensor
+    auto out_mean_iou_t = EigenTensor<float, 1>::From(*out_mean_iou);
+    auto out_wrong_t = EigenTensor<int, 1>::From(*out_wrong);
+    auto out_correct_t = EigenTensor<int, 1>::From(*out_correct);
+
+    // Tmp tensor
+    Tensor denominator;
+    Tensor valid_count;
+    Tensor iou_sum;
+
+    // get data ptr of tmp tensor
+    int* denominator_data = denominator.mutable_data<int>(
+        {static_cast<int64_t>(num_classes)}, ctx.GetPlace());
+    int* valid_count_data = valid_count.mutable_data<int>({1}, ctx.GetPlace());
+    float* iou_sum_data = iou_sum.mutable_data<float>({1}, ctx.GetPlace());
+
+    // get eigen tensor of tmp tensor
+    auto denominator_t = EigenTensor<int, 1>::From(denominator);
+    auto valid_count_t = EigenTensor<int, 1>::From(valid_count);
+    auto iou_sum_t = EigenTensor<float, 1>::From(iou_sum);
+
+    // init out_wrong, out_correct and out_mean_iou
+    out_wrong_t = out_wrong_t.constant(0);
+    out_correct_t = out_correct_t.constant(0);
+    out_mean_iou_t = out_mean_iou_t.constant(0);
+
+    // collect pre wrong, correct and mean_iou
+    auto in_mean_ious = ctx.MultiInput<Tensor>("InMeanIou");
+    for (size_t i = 0; i < in_mean_ious.size(); ++i) {
+      out_mean_iou_t.device(place) +=
+          EigenTensor<float, 1>::From(*in_mean_ious[i]);
+    }
+    auto in_wrongs = ctx.MultiInput<Tensor>("InWrongs");
+    for (size_t i = 0; i < in_wrongs.size(); ++i) {
+      out_wrong_t.device(place) += EigenTensor<int, 1>::From(*in_wrongs[i]);
+    }
+    auto in_corrects = ctx.MultiInput<Tensor>("InCorrects");
+    for (size_t i = 0; i < in_corrects.size(); ++i) {
+      out_correct_t.device(place) += EigenTensor<int, 1>::From(*in_corrects[i]);
+    }
+
+    // compute
+    for (int64_t i = 0; i < predictions->numel(); ++i) {
+      if (predictions_data[i] == labels_data[i]) {
+        out_correct_data[predictions_data[i]] += 1;
+      } else {
+        out_wrong_data[labels_data[i]] += 1;
+        out_wrong_data[predictions_data[i]] += 1;
+      }
+    }
+
+    denominator_t = out_wrong_t + out_correct_t;
+    valid_count_t =
+        (denominator_t > denominator_t.constant(0.0f)).cast<int>().sum();
+
+    for (int i = 0; i < num_classes; ++i) {
+      if (denominator_data[i] == 0) {
+        denominator_data[i] = 1;
+      }
+    }
+
+    iou_sum_t =
+        (out_correct_t.cast<float>() / denominator_t.cast<float>()).sum();
+    out_mean_iou_data[0] += (iou_sum_data[0] / valid_count_data[0]);
+  }
+};
+
+}  // namespace operators
+}  // namespace paddle

python/paddle/fluid/layers/nn.py

@@ -25,68 +25,20 @@ import utils
 import random
 
 __all__ = [
-    'fc',
-    'embedding',
-    'dynamic_lstm',
-    'dynamic_lstmp',
-    'dynamic_gru',
-    'gru_unit',
-    'linear_chain_crf',
-    'crf_decoding',
-    'cos_sim',
-    'cross_entropy',
-    'square_error_cost',
-    'chunk_eval',
-    'sequence_conv',
-    'conv2d',
-    'sequence_pool',
-    'sequence_softmax',
-    'softmax',
-    'pool2d',
-    'batch_norm',
-    'beam_search_decode',
-    'conv2d_transpose',
-    'sequence_expand',
-    'lstm_unit',
-    'reduce_sum',
-    'reduce_mean',
-    'reduce_max',
-    'reduce_min',
-    'reduce_prod',
-    'sequence_first_step',
-    'sequence_last_step',
-    'dropout',
-    'split',
-    'ctc_greedy_decoder',
-    'edit_distance',
-    'l2_normalize',
-    'matmul',
-    'topk',
-    'warpctc',
-    'sequence_reshape',
-    'transpose',
-    'im2sequence',
-    'nce',
-    'beam_search',
-    'row_conv',
-    'multiplex',
-    'layer_norm',
-    'softmax_with_cross_entropy',
-    'smooth_l1',
-    'one_hot',
-    'autoincreased_step_counter',
-    'reshape',
-    'lod_reset',
-    'lrn',
-    'pad',
-    'label_smooth',
-    'roi_pool',
-    'dice_loss',
-    'image_resize',
-    'image_resize_short',
-    'resize_bilinear',
-    'gather',
-    'random_crop',
+    'fc', 'embedding', 'dynamic_lstm', 'dynamic_lstmp', 'dynamic_gru',
+    'gru_unit', 'linear_chain_crf', 'crf_decoding', 'cos_sim', 'cross_entropy',
+    'square_error_cost', 'chunk_eval', 'sequence_conv', 'conv2d',
+    'sequence_pool', 'sequence_softmax', 'softmax', 'pool2d', 'batch_norm',
+    'beam_search_decode', 'conv2d_transpose', 'sequence_expand', 'lstm_unit',
+    'reduce_sum', 'reduce_mean', 'reduce_max', 'reduce_min', 'reduce_prod',
+    'sequence_first_step', 'sequence_last_step', 'dropout', 'split',
+    'ctc_greedy_decoder', 'edit_distance', 'l2_normalize', 'matmul', 'topk',
+    'warpctc', 'sequence_reshape', 'transpose', 'im2sequence', 'nce',
+    'beam_search', 'row_conv', 'multiplex', 'layer_norm',
+    'softmax_with_cross_entropy', 'smooth_l1', 'one_hot',
+    'autoincreased_step_counter', 'reshape', 'lod_reset', 'lrn', 'pad',
+    'label_smooth', 'roi_pool', 'dice_loss', 'image_resize',
+    'image_resize_short', 'resize_bilinear', 'gather', 'random_crop', 'mean_iou'
 ]
 
 
@@ -4231,6 +4183,7 @@ def gather(input, index):
         output (Variable): The output is a tensor with the same rank as input.
 
     Examples:
+
         .. code-block:: python
 
             output = fluid.layers.gather(x, index)
@@ -4295,3 +4248,53 @@ def random_crop(x, shape, seed=None):
                  "SeedOut": seed_out},
         attrs={"shape": shape})
     return out
+
+
+def mean_iou(input, label, num_classes):
+    """
+    Mean Intersection-Over-Union is a common evaluation metric for
+    semantic image segmentation, which first computes the IOU for each 
+    semantic class and then computes the average over classes. 
+    IOU is defined as follows: 
+    
+    .. math::
+        
+        IOU = true_positive / (true_positive + false_positive + false_negative). 
+
+    The predictions are accumulated in a confusion matrix and mean-IOU 
+    is then calculated from it.
+
+
+    Args:
+        input (Variable): A Tensor of prediction results for semantic labels with type int32 or int64.
+        label (Variable):  A Tensor of ground truth labels with type int32 or int64. 
+                           Its shape should be the same as input.
+
+    Returns:
+        mean_iou (Variable): A Tensor representing the mean intersection-over-union with shape [1].
+        out_wrong(Variable): A Tensor with shape [num_classes]. The wrong numbers of each class.
+        out_correct(Variable): A Tensor with shape [num_classes]. The correct numbers of each class. 
+
+
+    Examples:
+
+        .. code-block:: python
+
+            iou, wrongs, corrects = fluid.layers.mean_iou(predict, label, num_classes)
+    """
+    helper = LayerHelper('mean_iou', **locals())
+    dtype = helper.input_dtype()
+    out_mean_iou = helper.create_tmp_variable(dtype='float32')
+    out_wrong = helper.create_tmp_variable(dtype='int32')
+    out_correct = helper.create_tmp_variable(dtype='int32')
+    helper.append_op(
+        type="mean_iou",
+        inputs={"predictions": input,
+                "labels": label},
+        outputs={
+            "out_mean_iou": out_mean_iou,
+            "out_wrong": out_wrong,
+            "out_correct": out_correct
+        },
+        attrs={"num_classes": num_classes})
+    return out_mean_iou, out_wrong, out_correct

python/paddle/fluid/tests/unittests/test_mean_iou.py

+#   Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import division
+import unittest
+import numpy as np
+from op_test import OpTest
+
+
+def compute_mean_iou(predictions, labels, num_classes, in_wrongs, in_corrects,
+                     in_mean_ious):
+    assert predictions.shape == labels.shape
+    predictions = predictions.flatten()
+    labels = labels.flatten()
+
+    out_wrong = np.zeros([num_classes]).astype("int32")
+    for _, wrong in in_wrongs:
+        out_wrong += wrong
+    out_correct = np.zeros([num_classes]).astype("int32")
+    for _, correct in in_corrects:
+        out_correct += correct
+
+    for pred, label in zip(predictions, labels):
+        if pred == label:
+            out_correct[pred] += 1
+        else:
+            out_wrong[pred] += 1
+            out_wrong[label] += 1
+
+    denominator = out_wrong + out_correct
+    valid_count = (denominator != 0).sum()
+    denominator = np.where(denominator > 0, denominator,
+                           np.ones(denominator.shape))
+    mean_iou = (out_correct / denominator).sum() / valid_count
+
+    for _, in_mean_iou in in_mean_ious:
+        mean_iou += in_mean_iou
+    return mean_iou, out_wrong, out_correct
+
+
+class TestMeanIOUOp(OpTest):
+    def setUp(self):
+        self.config()
+        self.op_type = "mean_iou"
+        predictions = np.random.randint(0, self.num_classes,
+                                        self.image_size).astype("int32")
+        labels = np.random.randint(0, self.num_classes,
+                                   self.image_size).astype("int32")
+
+        in_wrongs = []
+        for i in range(self.in_wrong_num):
+            in_wrongs.append(("in_wrong_%d" % i, np.random.randint(
+                0, 10, [self.num_classes]).astype("int32")))
+
+        in_corrects = []
+        for i in range(self.in_correct_num):
+            in_corrects.append(("in_correct_%d" % i, np.random.randint(
+                0, 10, [self.num_classes]).astype("int32")))
+
+        in_mean_ious = []
+        for i in range(self.in_mean_iou_num):
+            in_mean_ious.append(("in_mean_iou_%d" % i, np.random.uniform(
+                0, 1, [1]).astype("float32")))
+
+        self.inputs = {
+            'Predictions': predictions,
+            'Labels': labels,
+            'InWrongs': in_wrongs,
+            'InCorrects': in_corrects,
+            'InMeanIou': in_mean_ious
+        }
+        self.attrs = {'num_classes': long(self.num_classes)}
+        mean_iou, out_wrong, out_correct = compute_mean_iou(
+            predictions, labels, self.num_classes, in_wrongs, in_corrects,
+            in_mean_ious)
+        self.outputs = {
+            'OutMeanIou': mean_iou,
+            'OutWrong': out_wrong,
+            'OutCorrect': out_correct
+        }
+
+    def config(self):
+        self.num_classes = 10
+        self.image_size = [128, 128]
+        self.in_wrong_num = 0
+        self.in_correct_num = 0
+        self.in_mean_iou_num = 0
+
+    def test_check_output(self):
+        self.check_output()
+
+
+class TestCase1(TestMeanIOUOp):
+    def config(self):
+        self.num_classes = 5
+        self.image_size = [100, 128]
+        self.in_wrong_num = 2
+        self.in_correct_num = 2
+        self.in_mean_iou_num = 2
+
+
+if __name__ == '__main__':
+    unittest.main()