Examples

The following are code example snippets and full examples of using Core ML Tools to convert models.

For a Quick Start

Full example:

• Getting Started: Demonstrates how to convert an image classifier model trained using the TensorFlow Keras API to the Core ML format.

ML Program with Typed Execution

Full example:

• Typed Execution Workflow Example: Demonstrates a workflow for checking accuracy using ML Programs with Typed Execution.

TensorFlow 2

• Load and Convert Model Workflow

• TensorFlow 2 Workflow

• Convert a Pre-trained Model

• Convert a User-defined Model

Full examples:

• Getting Started: Demonstrates how to convert an image classifier model trained using the TensorFlow Keras API to the Core ML format.

• Converting TensorFlow 2 BERT Transformer Models: Converts an object of the tf.keras.Model class and a SavedModel in the TensorFlow 2 format.

TensorFlow 1

• Convert From TensorFlow 1.

• Export as Frozen Graph and Convert.

• Convert a Pre-trained Model.

Full examples:

• Converting a TensorFlow 1 Image Classifier: Demonstrates the importance of setting the image preprocessing parameters correctly during conversion to get the right results.

• Converting a TensorFlow 1 DeepSpeech Model: Demonstrates automatic handling of flexible shapes using automatic speech recognition.

PyTorch

• Convert from PyTorch.

• PyTorch Conversion Workflow.

• Model Tracing.

• Model Scripting

Full examples:

• Converting a Natural Language Processing Model: Combines tracing and scripting to convert a PyTorch natural language processing model.

• Converting a torchvision Model from PyTorch: Traces a torchvision MobileNetV2 model, adds preprocessing for image input, and then converts it to Core ML.

• Converting a PyTorch Segmentation Model: Converts a PyTorch segmentation model that takes an image and outputs a class prediction for each pixel of the image.

Model Intermediate Language (MIL)

Full example:

• Model Intermediate Language: Construct a MIL program using the Python builder.”

Conversion Options

Image Inputs

• Use an MLMultiArray.

• Use an ImageType.

• Add Image Preprocessing Options.

Classifiers

• Produce a Classifier Model.

Flexible Input Shapes

• Select from Predetermined Shapes.

• Set the Range for Each Dimension.

• Update a Core ML Model to Use Flexible Input shapes

Composite and Custom Operators

• Composite Operators: Defining a composite operation by decomposing it into MIL operations.

Full example:

• Custom Operators: Augment Core ML with your own operators and implement them in Swift.

Optimization

Full examples:

• Training-Time Compression Examples: Use magnitude pruning, linear quantization, or palettization while training your model, or start from a pre-trained model and fine-tune it with training data.

• Compressing Neural Network Weights: Reduce the size of a neural network by reducing the number of bits that represent a number.

Trees and Linear Models

• LibSVM

• Scikit-learn

• XGBoost

MLModel

MLModel Overview

• Load and save the MLModel.

• Use the MLModel for Prediction.

• Work with the Spec.

• Update the Metadata and Input/output Descriptions.

Model Prediction

• Make Predictions

• Multi-array Prediction

• Image Prediction

• Image Prediction for a Multi-array Model

• Predict From the Compiled Model

Full example:

• Compiled Model Timing Example: Demonstrates timing differences with calling a large model.

Xcode Model Preview Types

Full examples:

• Segmentation Example

• Body Pose Example

MLModel Utilities

• Rename a Feature.

• Convert All Double Multi-array Feature Descriptions to Float.

• Evaluate Classifier, Regressor, and Transformer models.

Updatable Models

Full examples:

• Nearest Neighbor Classifier: Create an updatable empty k-nearest neighbor.

• Neural Network Classifier: Create a simple convolutional model with Keras, convert the model to Core ML, and make the model updatable.

• Pipeline Classifier: Use a pipeline composed of a drawing-embedding model and a nearest neighbor classifier to create a model for training a sketch classifier. If you have a code example you’d like to submit, see Contributing.