COMPMID-1750: Add PriorBox operator to graph API.

Change-Id: I5d2ed5dcc342abff8124762f7bdee587cdf20032

10 files changed, 303 insertions, 52 deletions

diff --git a/arm_compute/graph/GraphBuilder.h b/arm_compute/graph/GraphBuilder.h
index 22fc041684..57ce349984 100644
--- a/arm_compute/graph/GraphBuilder.h
+++ b/arm_compute/graph/GraphBuilder.h
@@ -308,6 +308,17 @@ public:
      * @return Node ID of the created node, EmptyNodeID in case of error
      */
     static NodeID add_pooling_node(Graph &g, NodeParams params, NodeIdxPair input, PoolingLayerInfo pool_info);
+    /** Adds a priorbox layer node to the graph
+     *
+     * @param[in] g          Graph to add the node to
+     * @param[in] params     Common node parameters
+     * @param[in] input0     First input to the priorbox layer node as a NodeID-Index pair
+     * @param[in] input1     Second input to the priorbox layer node as a NodeID-Index pair
+     * @param[in] prior_info PriorBox parameters
+     *
+     * @return Node ID of the created node, EmptyNodeID in case of error
+     */
+    static NodeID add_priorbox_node(Graph &g, NodeParams params, NodeIdxPair input0, NodeIdxPair input1, PriorBoxLayerInfo prior_info);
     /** Adds a reorg layer node to the graph
      *
      * @param[in] g      Graph to add the node to
diff --git a/arm_compute/graph/INodeVisitor.h b/arm_compute/graph/INodeVisitor.h
index a21c9b2d48..2df2574d62 100644
--- a/arm_compute/graph/INodeVisitor.h
+++ b/arm_compute/graph/INodeVisitor.h
@@ -111,6 +111,11 @@ public:
      * @param[in] n Node to visit.
      */
     virtual void visit(PoolingLayerNode &n) = 0;
+    /** Visit PriorBoxLayerNode.
+     *
+     * @param[in] n Node to visit.
+     */
+    virtual void visit(PriorBoxLayerNode &n) = 0;
     /** Visit ReshapeLayerNode.
      *
      * @param[in] n Node to visit.
@@ -201,6 +206,10 @@ public:
     {
         default_visit();
     }
+    virtual void visit(PriorBoxLayerNode &n) override
+    {
+        default_visit();
+    }
     virtual void visit(ReshapeLayerNode &n) override
     {
         default_visit();
diff --git a/arm_compute/graph/TypePrinter.h b/arm_compute/graph/TypePrinter.h
index c66f9cb374..d633091d16 100644
--- a/arm_compute/graph/TypePrinter.h
+++ b/arm_compute/graph/TypePrinter.h
@@ -113,6 +113,9 @@ inline ::std::ostream &operator<<(::std::ostream &os, const NodeType &node_type)
         case NodeType::PoolingLayer:
             os << "PoolingLayer";
             break;
+        case NodeType::PriorBoxLayer:
+            os << "PriorBoxLayer";
+            break;
         case NodeType::ReorgLayer:
             os << "ReorgLayer";
             break;
diff --git a/arm_compute/graph/Types.h b/arm_compute/graph/Types.h
index 24c24d328f..b6803c89bc 100644
--- a/arm_compute/graph/Types.h
+++ b/arm_compute/graph/Types.h
@@ -51,6 +51,7 @@ using arm_compute::FullyConnectedLayerInfo;
 using arm_compute::PadStrideInfo;
 using arm_compute::PoolingLayerInfo;
 using arm_compute::PoolingType;
+using arm_compute::PriorBoxLayerInfo;
 using arm_compute::DimensionRoundingType;
 using arm_compute::InterpolationPolicy;
 
@@ -141,6 +142,7 @@ enum class NodeType
     PadLayer,
     PermuteLayer,
     PoolingLayer,
+    PriorBoxLayer,
     ReorgLayer,
     ReshapeLayer,
     ResizeLayer,
diff --git a/arm_compute/graph/backends/FunctionHelpers.h b/arm_compute/graph/backends/FunctionHelpers.h
index e556e2f284..0d7210f7f8 100644
--- a/arm_compute/graph/backends/FunctionHelpers.h
+++ b/arm_compute/graph/backends/FunctionHelpers.h
@@ -72,9 +72,9 @@ template <typename TargetInfo>
 void validate_node(const INode &node, size_t num_expected_inputs, size_t num_expected_outputs)
 {
     ARM_COMPUTE_LOG_GRAPH_VERBOSE("Creating " << node.type()
-                                  << " Target : " << TargetInfo::TargetType
-                                  << " ID : " << node.id()
-                                  << " Name: " << node.name()
+                                  << " Target: " << TargetInfo::TargetType
+                                  << " ID: " << node.id()
+                                  << node.name()
                                   << std::endl);
 
     ARM_COMPUTE_ERROR_ON(TargetInfo::TargetType != node.assigned_target());
@@ -105,7 +105,9 @@ std::unique_ptr<IFunction> create_activation_layer(ActivationLayerNode &node)
     auto func = support::cpp14::make_unique<ActivationLayerFunction>();
     func->configure(input, output, act_info);
 
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << node.type()
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << node.type()
                                << " Target " << TargetInfo::TargetType
                                << " Data Type: " << input->info()->data_type()
                                << " Shape: " << input->info()->tensor_shape()
@@ -147,13 +149,15 @@ std::unique_ptr<IFunction> create_batch_normalization_layer(BatchNormalizationLa
     func->configure(input, output, mean, var, beta, gamma, epsilon, fused_act);
 
     // Log info
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << node.type()
-                               << " Target " << TargetInfo::TargetType
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << node.type()
+                               << " Target: " << TargetInfo::TargetType
                                << " Data Type: " << input->info()->data_type()
                                << " Shape: " << input->info()->tensor_shape()
                                << " Epsilon: " << epsilon << " "
                                << (fused_act.enabled() ? to_string(fused_act.activation()) : "")
-                               << " InPlace : " << is_in_place_operation(input, output)
+                               << " InPlace: " << is_in_place_operation(input, output)
                                << std::endl);
 
     return std::move(func);
@@ -218,8 +222,10 @@ std::unique_ptr<IFunction> create_channel_shuffle_layer(ChannelShuffleLayerNode
     auto func = support::cpp14::make_unique<ChannelShuffleLayerFunction>();
     func->configure(input, output, num_groups);
 
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << node.type()
-                               << " Target " << TargetInfo::TargetType
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << node.type()
+                               << " Target: " << TargetInfo::TargetType
                                << " Data Type: " << input->info()->data_type()
                                << " Shape: " << input->info()->tensor_shape()
                                << " Num groups: " << num_groups
@@ -263,8 +269,10 @@ std::unique_ptr<arm_compute::IFunction> create_concatenate_layer(ConcatenateLaye
     func->configure(inputs, output, concat_axis);
 
     // Log info
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << node.type()
-                               << " Target " << TargetInfo::TargetType
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << node.type()
+                               << " Target: " << TargetInfo::TargetType
                                << " Data Type: " << output->info()->data_type()
                                << " Shape: " << output->info()->tensor_shape()
                                << " Num Inputs: " << inputs.size()
@@ -350,8 +358,10 @@ std::unique_ptr<IFunction> create_convolution_layer(ConvolutionLayerNode &node,
             << " Weights QuantInfo: " << weights->info()->quantization_info()
             << " Output QuantInfo: " << output->info()->quantization_info();
     }
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << func_name
-                               << " Target " << TargetInfo::TargetType
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << func_name
+                               << " Target: " << TargetInfo::TargetType
                                << " Data Type: " << input->info()->data_type()
                                << " Groups: " << num_groups
                                << qss.str()
@@ -396,8 +406,10 @@ std::unique_ptr<IFunction> create_deconvolution_layer(DeconvolutionLayerNode &no
                                       input, weights, biases, output, deconv_info, inner_border.x(), inner_border.y());
 
     // Log info
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << node.type()
-                               << " Target " << TargetInfo::TargetType
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << node.type()
+                               << " Target: " << TargetInfo::TargetType
                                << " Data Type: " << input->info()->data_type()
                                << " Input shape: " << input->info()->tensor_shape()
                                << " Weights shape: " << weights->info()->tensor_shape()
@@ -462,8 +474,10 @@ std::unique_ptr<IFunction> create_depthwise_convolution_layer(DepthwiseConvoluti
             << " Weights QuantInfo: " << weights->info()->quantization_info()
             << " Output QuantInfo: " << output->info()->quantization_info();
     }
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << func_name
-                               << " Target " << TargetInfo::TargetType
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << func_name
+                               << " Target: " << TargetInfo::TargetType
                                << " Data Type: " << input->info()->data_type()
                                << qss.str()
                                << " Input shape: " << input->info()->tensor_shape()
@@ -524,11 +538,13 @@ std::unique_ptr<IFunction> create_eltwise_layer(EltwiseLayerNode &node)
     }
 
     // Log info
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << node.type()
-                               << " Target " << TargetInfo::TargetType
-                               << " Operation " << func_name
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << node.type()
+                               << " Target: " << TargetInfo::TargetType
+                               << " Operation: " << func_name
                                << " Data Type: " << input1->info()->data_type()
-                               << " Shape : " << input1->info()->tensor_shape()
+                               << " Shape: " << input1->info()->tensor_shape()
                                << std::endl);
 
     return func;
@@ -560,8 +576,10 @@ std::unique_ptr<IFunction> create_flatten_layer(FlattenLayerNode &node)
     func->configure(input, output);
 
     // Log info
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << node.type()
-                               << " Target " << TargetInfo::TargetType
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << node.type()
+                               << " Target: " << TargetInfo::TargetType
                                << " Data Type: " << input->info()->data_type()
                                << " Input shape: " << input->info()->tensor_shape()
                                << " Output shape: " << output->info()->tensor_shape()
@@ -610,8 +628,10 @@ std::unique_ptr<IFunction> create_fully_connected_layer(FullyConnectedLayerNode
             << " Weights QuantInfo: " << weights->info()->quantization_info()
             << " Output QuantInfo: " << output->info()->quantization_info();
     }
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << node.type()
-                               << " Target " << TargetInfo::TargetType
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << node.type()
+                               << " Target: " << TargetInfo::TargetType
                                << " Data Type: " << input->info()->data_type()
                                << qss.str()
                                << " Input shape: " << input->info()->tensor_shape()
@@ -700,8 +720,10 @@ std::unique_ptr<IFunction> create_normalization_layer(NormalizationLayerNode &no
     func->configure(input, output, norm_info);
 
     // Log info
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << node.type()
-                               << " Target " << TargetInfo::TargetType
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << node.type()
+                               << " Target: " << TargetInfo::TargetType
                                << " Data Type: " << input->info()->data_type()
                                << " Input shape: " << input->info()->tensor_shape()
                                << " Output shape: " << output->info()->tensor_shape()
@@ -740,8 +762,10 @@ std::unique_ptr<IFunction> create_normalize_planar_yuv_layer(NormalizePlanarYUVL
     func->configure(input, output, mean, std);
 
     // Log info
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << node.type()
-                               << " Target " << TargetInfo::TargetType
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << node.type()
+                               << " Target: " << TargetInfo::TargetType
                                << " Data Type: " << input->info()->data_type()
                                << " Shape: " << input->info()->tensor_shape()
                                << std::endl);
@@ -775,8 +799,10 @@ std::unique_ptr<IFunction> create_pad_layer(PadLayerNode &node)
     func->configure(input, output, padding);
 
     // Log info
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << node.type()
-                               << " Target " << TargetInfo::TargetType
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << node.type()
+                               << " Target: " << TargetInfo::TargetType
                                << " Data Type: " << input->info()->data_type()
                                << " Input shape: " << input->info()->tensor_shape()
                                << " Output shape: " << output->info()->tensor_shape()
@@ -811,8 +837,10 @@ std::unique_ptr<IFunction> create_permute_layer(PermuteLayerNode &node)
     func->configure(input, output, perm);
 
     // Log info
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << node.type()
-                               << " Target " << TargetInfo::TargetType
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << node.type()
+                               << " Target: " << TargetInfo::TargetType
                                << " Data Type: " << input->info()->data_type()
                                << " Input shape: " << input->info()->tensor_shape()
                                << " Output shape: " << output->info()->tensor_shape()
@@ -848,8 +876,10 @@ std::unique_ptr<IFunction> create_pooling_layer(PoolingLayerNode &node)
     func->configure(input, output, pool_info);
 
     // Log info
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << node.type()
-                               << " Target " << TargetInfo::TargetType
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << node.type()
+                               << " Target: " << TargetInfo::TargetType
                                << " Data Type: " << input->info()->data_type()
                                << " Input shape: " << input->info()->tensor_shape()
                                << " Output shape: " << output->info()->tensor_shape()
@@ -859,6 +889,48 @@ std::unique_ptr<IFunction> create_pooling_layer(PoolingLayerNode &node)
     return std::move(func);
 }
 
+/** Create a backend priorbox layer function
+ *
+ * @tparam PriorBoxLayerFunction Backend priorbox function
+ * @tparam TargetInfo           Target-specific information
+ *
+ * @param[in] node Node to create the backend function for
+ *
+ * @return Backend priorbox layer function
+ */
+template <typename PriorBoxLayerFunction, typename TargetInfo>
+std::unique_ptr<IFunction> create_priorbox_layer(PriorBoxLayerNode &node)
+{
+    validate_node<TargetInfo>(node, 2 /* expected inputs */, 1 /* expected outputs */);
+
+    // Extract IO and info
+    typename TargetInfo::TensorType *input0     = get_backing_tensor<TargetInfo>(node.input(0));
+    typename TargetInfo::TensorType *input1     = get_backing_tensor<TargetInfo>(node.input(1));
+    typename TargetInfo::TensorType *output     = get_backing_tensor<TargetInfo>(node.output(0));
+    const PriorBoxLayerInfo          prior_info = node.priorbox_info();
+    ARM_COMPUTE_ERROR_ON(input0 == nullptr);
+    ARM_COMPUTE_ERROR_ON(input1 == nullptr);
+    ARM_COMPUTE_ERROR_ON(output == nullptr);
+
+    // Create and configure function
+    auto func = support::cpp14::make_unique<PriorBoxLayerFunction>();
+    func->configure(input0, input1, output, prior_info);
+
+    // Log info
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << node.type()
+                               << " Target: " << TargetInfo::TargetType
+                               << " Data Type: " << input0->info()->data_type()
+                               << " Input0 shape: " << input0->info()->tensor_shape()
+                               << " Input1 shape: " << input1->info()->tensor_shape()
+                               << " Output shape: " << output->info()->tensor_shape()
+                               << " PriorBoxLayer info: " << prior_info
+                               << std::endl);
+
+    return std::move(func);
+}
+
 /** Create a backend reorg layer function
  *
  * @tparam ReorgLayerFunction Backend reorg function
@@ -884,8 +956,10 @@ std::unique_ptr<IFunction> create_reorg_layer(ReorgLayerNode &node)
     func->configure(input, output, node.stride());
 
     // Log info
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << node.type()
-                               << " Target " << TargetInfo::TargetType
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << node.type()
+                               << " Target: " << TargetInfo::TargetType
                                << " Data Type: " << input->info()->data_type()
                                << " Input shape: " << input->info()->tensor_shape()
                                << " Output shape: " << output->info()->tensor_shape()
@@ -919,8 +993,10 @@ std::unique_ptr<IFunction> create_reshape_layer(ReshapeLayerNode &node)
     func->configure(input, output);
 
     // Log info
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << node.type()
-                               << " Target " << TargetInfo::TargetType
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << node.type()
+                               << " Target: " << TargetInfo::TargetType
                                << " Data Type: " << input->info()->data_type()
                                << " Input shape: " << input->info()->tensor_shape()
                                << " Output shape: " << output->info()->tensor_shape()
@@ -955,8 +1031,10 @@ std::unique_ptr<IFunction> create_resize_layer(ResizeLayerNode &node)
     func->configure(input, output, policy, BorderMode::CONSTANT);
 
     // Log info
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << node.type()
-                               << " Target " << TargetInfo::TargetType
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << node.type()
+                               << " Target: " << TargetInfo::TargetType
                                << " Data Type: " << input->info()->data_type()
                                << " Input shape: " << input->info()->tensor_shape()
                                << " Output shape: " << output->info()->tensor_shape()
@@ -1034,8 +1112,10 @@ std::unique_ptr<IFunction> create_slice_layer(SliceLayerNode &node)
     func->configure(input, output, node.starts(), node.ends());
 
     // Log info
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << node.type()
-                               << " Target " << TargetInfo::TargetType
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << node.type()
+                               << " Target: " << TargetInfo::TargetType
                                << " Data Type: " << input->info()->data_type()
                                << " Input shape: " << input->info()->tensor_shape()
                                << " Output shape: " << output->info()->tensor_shape()
@@ -1071,8 +1151,10 @@ std::unique_ptr<IFunction> create_softmax_layer(SoftmaxLayerNode &node, GraphCon
     func->configure(input, output, beta);
 
     // Log info
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << node.type()
-                               << " Target " << TargetInfo::TargetType
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << node.type()
+                               << " Target: " << TargetInfo::TargetType
                                << " Data Type: " << input->info()->data_type()
                                << " Input shape: " << input->info()->tensor_shape()
                                << " Output shape: " << output->info()->tensor_shape()
@@ -1110,8 +1192,10 @@ std::unique_ptr<IFunction> create_upsample_layer(UpsampleLayerNode &node, GraphC
     func->configure(input, output, info, upsampling_policy);
 
     // Log info
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << node.type()
-                               << " Target " << TargetInfo::TargetType
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << node.type()
+                               << " Target: " << TargetInfo::TargetType
                                << " Data Type: " << input->info()->data_type()
                                << " Input shape: " << input->info()->tensor_shape()
                                << " Output shape: " << output->info()->tensor_shape()
@@ -1150,8 +1234,10 @@ std::unique_ptr<IFunction> create_yolo_layer(YOLOLayerNode &node, GraphContext &
     func->configure(input, output, act_info, num_classes);
 
     // Log info
-    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << node.type()
-                               << " Target " << TargetInfo::TargetType
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "
+                               << node.name()
+                               << " Type: " << node.type()
+                               << " Target: " << TargetInfo::TargetType
                                << " Data Type: " << input->info()->data_type()
                                << " Input shape: " << input->info()->tensor_shape()
                                << " Output shape: " << output->info()->tensor_shape()
diff --git a/arm_compute/graph/backends/ValidateHelpers.h b/arm_compute/graph/backends/ValidateHelpers.h
index 7c31a80967..a6864c2286 100644
--- a/arm_compute/graph/backends/ValidateHelpers.h
+++ b/arm_compute/graph/backends/ValidateHelpers.h
@@ -300,6 +300,29 @@ Status validate_permute_layer(PermuteLayerNode &node)
 
     return PermuteLayer::validate(input, output, perm);
 }
+/** Validates a priorbox layer node
+ *
+ * @tparam PriorBoxLayer PriorBox layer type
+ *
+ * @param[in] node Node to validate
+ *
+ * @return Status
+ */
+template <typename PriorBoxLayer>
+Status validate_priorbox_layer(PriorBoxLayerNode &node)
+{
+    ARM_COMPUTE_LOG_GRAPH_VERBOSE("Validating PriorBoxLayer node with ID : " << node.id() << " and Name: " << node.name() << std::endl);
+    ARM_COMPUTE_RETURN_ERROR_ON(node.num_inputs() != 2);
+    ARM_COMPUTE_RETURN_ERROR_ON(node.num_outputs() != 1);
+
+    // Extract IO and info
+    arm_compute::ITensorInfo *input0     = get_backing_tensor_info(node.input(0));
+    arm_compute::ITensorInfo *input1     = get_backing_tensor_info(node.input(1));
+    arm_compute::ITensorInfo *output     = get_backing_tensor_info(node.output(0));
+    const PriorBoxLayerInfo   prior_info = node.priorbox_info();
+
+    return PriorBoxLayer::validate(input0, input1, output, prior_info);
+}
 
 /** Validates a Reorg layer node
  *
diff --git a/arm_compute/graph/frontend/Layers.h b/arm_compute/graph/frontend/Layers.h
index 7ed448e3f2..78a3f20f1f 100644
--- a/arm_compute/graph/frontend/Layers.h
+++ b/arm_compute/graph/frontend/Layers.h
@@ -225,7 +225,27 @@ public:
      */
     template <typename... Ts>
     ConcatLayer(SubStream &&sub_stream1, SubStream &&sub_stream2, Ts &&... rest_sub_streams)
-        : _sub_streams()
+        : _sub_streams(), _axis(DataLayoutDimension::CHANNEL)
+    {
+        _sub_streams.push_back(arm_compute::support::cpp14::make_unique<SubStream>(std::move(sub_stream1)));
+        _sub_streams.push_back(arm_compute::support::cpp14::make_unique<SubStream>(std::move(sub_stream2)));
+
+        utility::for_each([&](SubStream && sub_stream)
+        {
+            _sub_streams.push_back(arm_compute::support::cpp14::make_unique<SubStream>(std::move(sub_stream)));
+        },
+        std::move(rest_sub_streams)...);
+    }
+    /** Construct a concatenation layer
+     *
+     * @param[in] axis             Axis over the concatenation will be performed
+     * @param[in] sub_stream1      First graph branch
+     * @param[in] sub_stream2      Second graph branch
+     * @param[in] rest_sub_streams Rest sub-graph branches
+     */
+    template <typename... Ts>
+    ConcatLayer(DataLayoutDimension axis, SubStream &&sub_stream1, SubStream &&sub_stream2, Ts &&... rest_sub_streams)
+        : _sub_streams(), _axis(axis)
     {
         _sub_streams.push_back(arm_compute::support::cpp14::make_unique<SubStream>(std::move(sub_stream1)));
         _sub_streams.push_back(arm_compute::support::cpp14::make_unique<SubStream>(std::move(sub_stream2)));
@@ -242,7 +262,7 @@ public:
      */
     template <typename... Ts>
     ConcatLayer(SubStream &&sub_stream)
-        : _sub_streams()
+        : _sub_streams(), _axis(DataLayoutDimension::CHANNEL)
     {
         _sub_streams.push_back(arm_compute::support::cpp14::make_unique<SubStream>(std::move(sub_stream)));
     }
@@ -269,13 +289,14 @@ public:
                     }
                 }
             }
-            nid = GraphBuilder::add_concatenate_node(s.graph(), common_params, nodes, DataLayoutDimension::CHANNEL);
+            nid = GraphBuilder::add_concatenate_node(s.graph(), common_params, nodes, _axis);
         }
         return nid;
     }
 
 private:
     std::vector<std::unique_ptr<SubStream>> _sub_streams;
+    DataLayoutDimension                     _axis;
 };
 
 /** Convolution Layer */
@@ -724,6 +745,33 @@ private:
     PoolingLayerInfo _pool_info;
 };
 
+/** PriorBox Layer */
+class PriorBoxLayer final : public ILayer
+{
+public:
+    /** Construct a priorbox layer.
+     *
+     * @param[in] sub_stream First graph sub-stream
+     * @param[in] prior_info PriorBox parameters.
+     */
+    PriorBoxLayer(SubStream &&sub_stream, PriorBoxLayerInfo prior_info)
+        : _ss(std::move(sub_stream)), _prior_info(prior_info)
+    {
+    }
+
+    NodeID create_layer(IStream &s) override
+    {
+        NodeParams  common_params = { name(), s.hints().target_hint };
+        NodeIdxPair input0        = { s.tail_node(), 0 };
+        NodeIdxPair input1        = { _ss.tail_node(), 0 };
+        return GraphBuilder::add_priorbox_node(s.graph(), common_params, input0, input1, _prior_info);
+    }
+
+private:
+    SubStream         _ss;
+    PriorBoxLayerInfo _prior_info;
+};
+
 /** Reorg Layer */
 class ReorgLayer final : public ILayer
 {
diff --git a/arm_compute/graph/nodes/Nodes.h b/arm_compute/graph/nodes/Nodes.h
index 342ecbfd3b..5c7599fbfd 100644
--- a/arm_compute/graph/nodes/Nodes.h
+++ b/arm_compute/graph/nodes/Nodes.h
@@ -45,6 +45,7 @@
 #include "arm_compute/graph/nodes/PadLayerNode.h"
 #include "arm_compute/graph/nodes/PermuteLayerNode.h"
 #include "arm_compute/graph/nodes/PoolingLayerNode.h"
+#include "arm_compute/graph/nodes/PriorBoxLayerNode.h"
 #include "arm_compute/graph/nodes/ROIAlignLayerNode.h"
 #include "arm_compute/graph/nodes/ReorgLayerNode.h"
 #include "arm_compute/graph/nodes/ReshapeLayerNode.h"
diff --git a/arm_compute/graph/nodes/NodesFwd.h b/arm_compute/graph/nodes/NodesFwd.h
index 8d9bad3771..f956b54c66 100644
--- a/arm_compute/graph/nodes/NodesFwd.h
+++ b/arm_compute/graph/nodes/NodesFwd.h
@@ -51,6 +51,7 @@ class OutputNode;
 class PadLayerNode;
 class PermuteLayerNode;
 class PoolingLayerNode;
+class PriorBoxLayerNode;
 class ReorgLayerNode;
 class ReshapeLayerNode;
 class ResizeLayerNode;
diff --git a/arm_compute/graph/nodes/PriorBoxLayerNode.h b/arm_compute/graph/nodes/PriorBoxLayerNode.h
new file mode 100644
index 0000000000..901fa0817a
--- /dev/null
+++ b/arm_compute/graph/nodes/PriorBoxLayerNode.h
@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2018 ARM Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#ifndef __ARM_COMPUTE_GRAPH_PRIORBOX_LAYER_NODE_H__
+#define __ARM_COMPUTE_GRAPH_PRIORBOX_LAYER_NODE_H__
+
+#include "arm_compute/graph/INode.h"
+
+namespace arm_compute
+{
+namespace graph
+{
+/** PriorBox Layer node */
+class PriorBoxLayerNode final : public INode
+{
+public:
+    /** Constructor
+     *
+     * @param[in] prior_info PriorBox Layer information
+     */
+    PriorBoxLayerNode(PriorBoxLayerInfo prior_info);
+    /** PriorBox metadata accessor
+     *
+     * @return PriorBox Layer info
+     */
+    PriorBoxLayerInfo priorbox_info() const;
+    /** Computes priorbox output descriptor
+     *
+     * @param[in] input_descriptor Input descriptor
+     * @param[in] info             PriorBox operation attributes
+     *
+     * @return Output descriptor
+     */
+    static TensorDescriptor compute_output_descriptor(const TensorDescriptor &input_descriptor, const PriorBoxLayerInfo &info);
+
+    // Inherited overridden methods:
+    NodeType         type() const override;
+    bool             forward_descriptors() override;
+    TensorDescriptor configure_output(size_t idx) const override;
+    void accept(INodeVisitor &v) override;
+
+private:
+    PriorBoxLayerInfo _info;
+};
+} // namespace graph
+} // namespace arm_compute
+#endif /* __ARM_COMPUTE_GRAPH_PRIORBOX_LAYER_NODE_H__ */