Streamlining the Machine Learning Workflow with ONNX and ONNX Runtime

Tamanna
4 min readMar 1, 2023

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Open Neural Network Exchange

Open Neural Network Exchange (ONNX) is an open-source framework that allows developers to create and deploy machine learning models across multiple platforms and hardware configurations. ONNX provides a standardized format for representing trained models, making it easier to share models between different frameworks and tools.

Usage: ONNX can be used in various applications, including computer vision, natural language processing, and speech recognition. It is compatible with popular machine learning frameworks such as PyTorch, TensorFlow, and Keras. To use ONNX, you first need to convert your trained model into the ONNX format using a conversion tool provided by ONNX. Once you have an ONNX model, you can use it for inference, optimization, and deployment across different platforms and hardware configurations.

Benefits: ONNX helps to streamline the machine learning workflow by enabling the transfer of models between different frameworks and tools. It also allows for more efficient model deployment, making it easier to optimize models for specific hardware configurations.

Versions: Currently, there are three versions of ONNX available: ONNX v1.10, ONNX v1.9, and ONNX v1.8. Each version adds new features and improves compatibility with different machine learning frameworks.

Installation: To install ONNX, you can use pip, the package manager for Python. Simply run the command pip install onnx to install the latest version of ONNX.

ONNX Runtime: ONNX Runtime is a high-performance engine for executing ONNX models on various hardware platforms, including CPUs, GPUs, and FPGAs. It provides an optimized and efficient runtime environment for inference and allows developers to deploy ONNX models on a variety of devices.

To use ONNX Runtime for inferencing machine learning models, you first need to load the ONNX model using the onnxruntime.InferenceSession class. This class takes the path to the ONNX model file as an argument and creates a runtime session for executing the model.

Here is an example of using ONNX Runtime to execute an ONNX model for image classification:

import onnxruntime
import numpy as np
from PIL import Image

# Load the ONNX model
session = onnxruntime.InferenceSession('model.onnx')

# Load and preprocess the image
image = Image.open('image.jpg').resize((224, 224))
image_data = np.asarray(image).astype('float32')
image_data = np.transpose(image_data, [2, 0, 1])
image_data = np.expand_dims(image_data, axis=0)

# Execute the model
output = session.run(None, {'input': image_data})

# Print the output probabilities
print(output[0])

This code loads an ONNX model from a file, preprocesses an image for classification, executes the model using ONNX Runtime, and prints the output probabilities.

ONNX Runtime provides a variety of inference runtime APIs for executing ONNX models, including the C++ API, C# API, and Python API. These APIs provide a low-level interface for integrating ONNX models into custom applications and workflows.

Open Neural Network Compiler (ONNC) is another open-source tool for optimizing and compiling ONNX models for specific hardware platforms. ONNC provides a modular and extensible framework for optimizing and transforming ONNX models, making it easier to deploy models on a variety of devices.

To convert a model into ONNX format, you can use a conversion tool provided by ONNX. For example, to convert a PyTorch model into ONNX format, you can use the torch.onnx.export function. Here is an example:

import torch
import onnx

# Load the PyTorch model
model = torch.load('model.pt')

# Convert the model to ONNX format
input_shape = (1, 3, 224, 224)
input_data = torch.randn(input_shape)
output_path = 'model.onnx'
torch.onnx.export(model, input_data, output_path, verbose=True)

This code loads a PyTorch model from a file, creates a sample input tensor, and exports the model to ONNX format using the torch.onnx.export function. The resulting ONNX model is saved to a file named 'model.onnx'.

In conclusion, ONNX is an important tool for creating and deploying machine learning models across different platforms and hardware configurations. It provides a standardized format for representing trained models and allows for more efficient model deployment and optimization. ONNX Runtime is a high-performance engine for executing ONNX models on various hardware platforms, and Open Neural Network Compiler (ONNC) is a tool for optimizing and compiling ONNX models for specific hardware platforms. By leveraging these tools, developers can create more efficient and scalable machine learning workflows and applications.

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Tamanna

Numbers have an important story to tell. They rely on you to give them a voice.