IVGCVSW-6294 Added support for LRN to TfLiteParser

 * Added support for LRN to TfLiteParser

Signed-off-by: Mike Kelly <mike.kelly@arm.com>
Change-Id: Ia34441a4adeecd1f17c65af047d6c207729703ec

1 files changed, 46 insertions, 0 deletions

diff --git a/src/armnnTfLiteParser/TfLiteParser.cpp b/src/armnnTfLiteParser/TfLiteParser.cpp
index 2ac325c08c..5c7cb9b0b8 100644
--- a/src/armnnTfLiteParser/TfLiteParser.cpp
+++ b/src/armnnTfLiteParser/TfLiteParser.cpp
@@ -657,6 +657,8 @@ TfLiteParserImpl::TfLiteParserImpl(const Optional<ITfLiteParser::TfLiteParserOpt
     m_ParserFunctions[tflite::BuiltinOperator_LEAKY_RELU]              = &TfLiteParserImpl::ParseLeakyRelu;
     m_ParserFunctions[tflite::BuiltinOperator_LESS]                    = &TfLiteParserImpl::ParseLess;
     m_ParserFunctions[tflite::BuiltinOperator_LESS_EQUAL]              = &TfLiteParserImpl::ParseLessOrEqual;
+    m_ParserFunctions[tflite::BuiltinOperator_LOCAL_RESPONSE_NORMALIZATION]
+            = &TfLiteParserImpl::ParseLocalResponseNormalization;
     m_ParserFunctions[tflite::BuiltinOperator_LOGICAL_NOT]             = &TfLiteParserImpl::ParseLogicalNot;
     m_ParserFunctions[tflite::BuiltinOperator_LOGISTIC]                = &TfLiteParserImpl::ParseLogistic;
     m_ParserFunctions[tflite::BuiltinOperator_L2_NORMALIZATION]        = &TfLiteParserImpl::ParseL2Normalization;
@@ -3401,6 +3403,50 @@ void TfLiteParserImpl::ParseExp(size_t subgraphIndex, size_t operatorIndex)
     ParseElementwiseUnary(subgraphIndex, operatorIndex, armnn::UnaryOperation::Exp);
 }
 
+void TfLiteParserImpl::ParseLocalResponseNormalization(size_t subgraphIndex, size_t operatorIndex)
+{
+    CHECK_MODEL(m_Model, subgraphIndex, operatorIndex);
+
+    auto inputs = GetInputs(m_Model, subgraphIndex, operatorIndex);
+    CHECK_VALID_SIZE(inputs.size(), 1);
+
+    auto outputs = GetOutputs(m_Model, subgraphIndex, operatorIndex);
+    CHECK_VALID_SIZE(outputs.size(), 1);
+
+    auto layerName = fmt::format("LRN:{}:{}", subgraphIndex, operatorIndex);
+    std::string layerNameFormatted = fmt::format(layerName, subgraphIndex, operatorIndex);
+
+    armnn::TensorInfo inputTensorInfo  = ToTensorInfo(inputs[0]);
+
+    const auto& operatorPtr = m_Model->subgraphs[subgraphIndex]->operators[operatorIndex];
+    const auto* options = operatorPtr->builtin_options.AsLocalResponseNormalizationOptions();
+
+    armnn::NormalizationDescriptor descriptor;
+    descriptor.m_DataLayout      = armnn::DataLayout::NHWC;
+    descriptor.m_NormChannelType = armnn::NormalizationAlgorithmChannel::Across;
+    descriptor.m_NormMethodType  = armnn::NormalizationAlgorithmMethod::LocalBrightness;
+    descriptor.m_NormSize = static_cast<uint32_t>(options->radius);
+    descriptor.m_K = options->bias;
+    descriptor.m_Alpha = options->alpha;
+    descriptor.m_Beta = options->beta;
+
+    // ArmNN expects normSize to be the full size of the normalization
+    // window rather than the radius as in TfLite.
+    descriptor.m_NormSize = 1 + (2 * descriptor.m_NormSize);
+
+    IConnectableLayer* layer = m_Network->AddNormalizationLayer(descriptor, layerNameFormatted.c_str());
+    ARMNN_ASSERT(layer != nullptr);
+
+    TensorInfo outputTensorInfo = ToTensorInfo(outputs[0], true);
+    layer->GetOutputSlot(0).SetTensorInfo(outputTensorInfo);
+
+    auto inputTensorIndexes = AsUnsignedVector(GetInputTensorIds(m_Model, subgraphIndex, operatorIndex));
+    RegisterInputSlots(subgraphIndex, operatorIndex, layer, {inputTensorIndexes[0]});
+
+    auto outputTensorIndexes = AsUnsignedVector(GetOutputTensorIds(m_Model, subgraphIndex, operatorIndex));
+    RegisterOutputSlots(subgraphIndex, operatorIndex, layer, {outputTensorIndexes[0]});
+}
+
 void TfLiteParserImpl::ParseLogicalNot(size_t subgraphIndex, size_t operatorIndex)
 {
     ParseElementwiseUnary(subgraphIndex, operatorIndex, armnn::UnaryOperation::LogicalNot);