openvino/docs/IE_DG/Graph_debug_capabilities.md

Graph Debug Capabilities

Inference Engine supports two different objects for a graph representation: the nGraph function and CNNNetwork. Both representations provide an API to get detailed information about the graph structure.

nGraph Function

To receive additional messages about applied graph modifications, rebuild the nGraph library with the -DNGRAPH_DEBUG_ENABLE=ON option.

To enable serialization and deserialization of the nGraph function to a JSON file, rebuild the nGraph library with the -DNGRAPH_JSON_ENABLE=ON option. To serialize or deserialize the nGraph function, call the nGraph function as follows:

#include <ngraph/serializer.hpp>

std::shared_ptr<ngraph::Function> nGraph;
...
ngraph::serialize("test_json.json", nGraph);        // For graph serialization
std::ifstream file("test_json.json");               // Open a JSON file
nGraph = ngraph::deserialize(file);                 // For graph deserialization

To visualize the nGraph function to the xDot format or to an image file, use the ngraph::pass::VisualizeTree graph transformation pass:

#include <ngraph/pass/visualize_tree.hpp>

std::shared_ptr<ngraph::Function> nGraph;
...
std::vector<std::shared_ptr<ngraph::Function>> g2{nGraph};
ngraph::pass::VisualizeTree("after.png").run_on_module(g2);     // Visualize the nGraph function to an image

CNNNetwork

To serialize the CNNNetwork to the Inference Engine Intermediate Representation (IR) format, use the CNNNetwork::serialize(...) method:

std::shared_ptr<ngraph::Function> nGraph;
...
CNNNetwork network(nGraph);
network.serialize("test_ir.xml", "test_ir.bin");

NOTE: CNNNetwork created from the nGraph function might differ from the original nGraph function because the Inference Engine applies some graph transformation.