Machine Learning for iOS

Last Update: January 12, 2018.

Curated list of resources for iOS developers in following topics:

• Core ML
• Machine Learning Libraries
• Deep Learning Libraries
  • Deep Learning: Model Compression
• Computer Vision
• Natural Language Processing
• Speech Recognition (TTS) and Generation (STT)
• Text Recognition (OCR)
• Other AI
• Machine Learning Web APIs
• Opensource ML Applications
• Game AI
• Other related staff
  • Linear algebra
  • Statistics, random numbers
  • Mathematical optimization
  • Feature extraction
  • Data Visualization
  • Bioinformatics (kinda)
  • Big Data (not really)
• iOS ML Blogs
• Mobile ML books
• GPU Computing Blogs
• Learn Machine Learning
• Other Lists

Most of the de-facto standard tools in AI-related domains are written in iOS-unfriendly languages (Python/Java/R/Matlab) so finding something appropriate for your iOS application may be a challenging task.

This list consists mainly of libraries written in Objective-C, Swift, C, C++, JavaScript and some other languages that can be easily ported to iOS. Also, I included links to some relevant web APIs, blog posts, videos and learning materials.

Resources are sorted alphabetically or randomly. The order doesn't reflect my personal preferences or anything else. Some of the resources are awesome, some are great, some are fun, and some can serve as an inspiration.

Have fun!

Pull-requests are welcome here.

Core ML

• coremltools is a Python package. It contains converters from some popular machine learning libraries to the Apple format.
• Core ML is an Apple framework to run inference on device. It is highly optimized to Apple hardware.

Currently CoreML is compatible (partially) with the following machine learning packages via coremltools python package:

• Caffe
• Keras
• libSVM
• scikit-learn
• XGBoost

Third-party converters to CoreML format are also available for some models from:

• Turicreate
• TensorFlow
• MXNet
• Torch7
• CatBoost

There are many curated lists of pre-trained neural networks in Core ML format: [1], [2], [3].

Core ML currently doesn't support training models, but still, you can replace model by downloading a new one from a server in runtime. Here is a demo of how to do it. It uses generator part of MNIST GAN as Core ML model.

General-Purpose Machine Learning Libraries

Library	Algorithms	Language	License	Code	Dependency manager
AIToolbox	Graphs/Trees Depth-first search Breadth-first search Hill-climb search Beam Search Optimal Path search Alpha-Beta (game tree) Genetic Algorithms Constraint Propogation Linear Regression Non-Linear Regression parameter-delta Gradient-Descent Gauss-Newton Logistic Regression Neural Networks multiple layers, several non-linearity models on-line and batch training feed-forward or simple recurrent layers can be mixed in one network LSTM network layer implemented - needs more testing gradient check routines Support Vector Machine K-Means Principal Component Analysis Markov Decision Process Monte-Carlo (every-visit, and first-visit) SARSA Single and Multivariate Gaussians Mixture Of Gaussians Model validation Deep Network Convolution layers Pooling layers Fully-connected NN layers	Swift	Apache 2.0	GitHub
dlib	Deep Learning Support Vector Machines Reduced-rank methods for large-scale classification and regression Relevance vector machines for classification and regression A Multiclass SVM Structural SVM A large-scale SVM-Rank An online kernel RLS regression An online SVM classification algorithm Semidefinite Metric Learning An online kernelized centroid estimator/novelty detector and offline support vector one-class classification Clustering algorithms: linear or kernel k-means, Chinese Whispers, and Newman clustering Radial Basis Function Networks Multi layer perceptrons	C++	Boost	GitHub
FANN	Multilayer Artificial Neural Network Backpropagation (RPROP, Quickprop, Batch, Incremental) Evolving topology training	C++	GNU LGPL 2.1	GitHub	Cocoa Pods
lbimproved	k-nearest neighbors and Dynamic Time Warping	C++	Apache 2.0	GitHub
MAChineLearning	Neural Networks Activation functions: Linear, ReLU, Step, sigmoid, TanH Cost functions: Squared error, Cross entropy Backpropagation: Standard, Resilient (a.k.a. RPROP). Training by sample or by batch. Bag of Words Word Vectors	Objective-C	BSD 3-clause	GitHub
MLKit	Linear Regression: simple, ridge, polynomial Multi-Layer Perceptron, & Adaline ANN Architectures K-Means Clustering Genetic Algorithms	Swift	MIT	GitHub	Cocoa Pods
Mendel	Evolutionary/genetic algorithms	Swift	?	GitHub
multilinear-math	Linear algebra and tensors Principal component analysis Multilinear subspace learning algorithms for dimensionality reduction Linear and logistic regression Stochastic gradient descent Feedforward neural networks Sigmoid ReLU Softplus activation functions	Swift	Apache 2.0	GitHub	Swift Package Manager
OpenCV	Multi-Layer Perceptrons Boosted tree classifier decision tree Expectation Maximization K-Nearest Neighbors Logistic Regression Bayes classifier Random forest Support Vector Machines Stochastic Gradient Descent SVM classifier Grid search Hierarchical k-means Deep neural networks	C++	3-clause BSD	GitHub	Cocoa Pods
Shark	Supervised: Linear discriminant analysis (LDA) Fisher–LDA Linear regression SVMs FF NN RNN Radial basis function networks Regularization networks Gaussian processes for regression Iterative nearest neighbor classification and regression Decision trees Random forest Unsupervised: PCA Restricted Boltzmann machines Hierarchical clustering Data structures for efficient distance-based clustering Optimization: Evolutionary algorithms Single-objective optimization (e.g., CMA–ES) Multi-objective optimization Basic linear algebra and optimization algorithms	C++	GNU LGPL	GitHub	Cocoa Pods
YCML	Gradient Descent Backpropagation Resilient Backpropagation (RProp) Extreme Learning Machines (ELM) Forward Selection using Orthogonal Least Squares (for RBF Net), also with the PRESS statistic Binary Restricted Boltzmann Machines (CD & PCD) Optimization algorithms: Gradient Descent (Single-Objective, Unconstrained) RProp Gradient Descent (Single-Objective, Unconstrained) NSGA-II (Multi-Objective, Constrained)	Objective-C	GNU GPL 3.0	GitHub
Kalvar Lin's libraries	ios-KRHebbian-Algorithm - Hebbian Theory ios-KRKmeans-Algorithm - K-Means clustering method. ios-KRFuzzyCMeans-Algorithm - Fuzzy C-Means, the fuzzy clustering algorithm. ios-KRGreyTheory - Grey Theory / Grey system theory-based models in time series prediction ios-KRSVM - Support Vector Machine and SMO. ios-KRKNN - kNN implementation. ios-KRRBFNN - Radial basis function neural network and OLS.	Objective-C	MIT	GitHub

Multilayer perceptron implementations:

• Brain.js - JS
• SNNeuralNet - Objective-C port of brain.js
• MLPNeuralNet - Objective-C, Accelerate
• Swift-AI - Swift
• SwiftSimpleNeuralNetwork - Swift
• ios-BPN-NeuralNetwork - Objective-C
• ios-Multi-Perceptron-NeuralNetwork- Objective-C
• ios-KRDelta - Objective-C
• ios-KRPerceptron - Objective-C

Deep Learning Libraries:

On-Device training and inference

• Birdbrain - RNNs and FF NNs on top of Metal and Accelerate. Not ready for production.
• BrainCore - simple but fast neural network framework written in Swift. It uses Metal framework to be as fast as possible. ReLU, LSTM, L2 ...
• Caffe - A deep learning framework developed with cleanliness, readability, and speed in mind. GitHub. [BSD]
  • iOS port
  • caffe-mobile - another iOS port.
  • C++ examples: Classifying ImageNet, Extracting Features
  • Caffe iOS sample
• Caffe2 - a cross-platform framework made with expression, speed, and modularity in mind.
  • Cocoa Pod
  • iOS demo app
• Convnet.js - ConvNetJS is a Javascript library for training Deep Learning models by Andrej Karpathy. GitHub
  • ConvNetSwift - Swift port [work in progress].
• Deep Belief SDK - The SDK for Jetpac's iOS Deep Belief image recognition framework
• TensorFlow - an open source software library for numerical computation using data flow graphs. Nodes in the graph represent mathematical operations, while the graph edges represent the multidimensional data arrays (tensors) communicated between them. The flexible architecture allows you to deploy computation to one or more CPUs or GPUs in a desktop, server, or mobile device with a single API.
  • iOS examples
  • another example
  • Perfect-TensorFlow - TensorFlow binding for Perfect (server-side Swift framework). Includes only C TF API.
• tiny-dnn - header only, dependency-free deep learning framework in C++11.
  • iOS example
• Torch is a scientific computing framework with wide support for machine learning algorithms.
  • Torch4iOS
  • Torch-iOS

Deep Learning: Running pre-trained models on device

These libraries doesn't support training, so you need to pre-train models in some ML framework.

• Bender - Framework for building fast NNs. Supports TensorFlow models. It uses Metal under the hood.
• Core ML
• DeepLearningKit - Open Source Deep Learning Framework from Memkite for Apple's tvOS, iOS and OS X.
• Espresso - A minimal high performance parallel neural network framework running on iOS.
• Forge - A neural network toolkit for Metal.
• Keras.js - run Keras models in a web view.
• KSJNeuralNetwork - A Neural Network Inference Library Built atop BNNS and MPS
  • Converter for Torch models
• MXNet - MXNet is a deep learning framework designed for both efficiency and flexibility.
  • Deploying pre-trained mxnet model to a smartphone
• Quantized-CNN - compressed convolutional neural networks for Mobile Devices
• WebDNN - You can run deep learning model in a web view if you want. Three modes: WebGPU acceleration, WebAssembly acceleration and pure JS (on CPU). No training, inference only.

Deep Learning: Low-level routines libraries

• BNNS - Apple Basic neural network subroutines (BNNS) is a collection of functions that you use to implement and run neural networks, using previously obtained training data.
  • BNNS usage examples in iOS 10 sampler.
  • An example of a neural network trained by tensorflow and executed using BNNS
• MetalPerformanceShaders - CNNs on GPU from Apple.
  • MetalCNNWeights - a Python script to convert Inception v3 for MPS.
  • MPSCNNfeeder - Keras to MPS models conversion.
• NNPACK - Acceleration package for neural networks on multi-core CPUs. Prisma uses this library in the mobile app.
• STEM - Swift Tensor Engine for Machine-learning
  • Documentation

Deep Learning: Model Compression

• TensorFlow implementation of knowledge distilling method
• MobileNet-Caffe - Caffe Implementation of Google's MobileNets
• keras-surgeon - Pruning for trained Keras models.

Computer Vision

• ccv - C-based/Cached/Core Computer Vision Library, A Modern Computer Vision Library
  • iOS demo app
• OpenCV – Open Source Computer Vision Library. [BSD]
  • OpenCV crash course
  • OpenCVSwiftStitch
  • Tutorial: using and building openCV on iOS devices
  • A Collection of OpenCV Samples For iOS
• OpenFace – a state-of-the art open source tool intended for facial landmark detection, head pose estimation, facial action unit recognition, and eye-gaze estimation.
  • iOS port
  • iOS demo
• trackingjs – Object tracking in JS
• Vision is an Apple framework for computer vision.

Natural Language Processing

• CoreLinguistics - POS tagging (HMM), ngrams, Naive Bayes, IBM alignment models.
• GloVe Swift package. Vector words representations.
• NSLinguisticTagger
• Parsimmon
• Twitter text - An Objective-C implementation of Twitter's text processing library. The library includes methods for extracting user names, mentions headers, hashtags, and more – all the tweet specific language syntax you could ever want.
• Verbal expressions for Swift, like regexps for humans.
• Word2Vec - Original C implementation of Word2Vec Deep Learning algorithm. Works on iPhone like a charm.

Speech Recognition (TTS) and Generation (STT)

• Kaldi-iOS framework - on-device speech recognition using deep learning.
  • Proof of concept app
• MVSpeechSynthesizer
• OpenEars™: free speech recognition and speech synthesis for the iPhone - OpenEars™ makes it simple for you to add offline speech recognition and synthesized speech/TTS to your iPhone app quickly and easily. It lets everyone get the great results of using advanced speech UI concepts like statistical language models and finite state grammars in their app, but with no more effort than creating an NSArray or NSDictionary.
  • Tutorial (Russian)
• TLSphinx, Tutorial

Text Recognition (OCR)

• ocrad.js - JS OCR
• Tesseract
  • Install and Use Tesseract on iOS
  • tesseract-ios-lib
  • tesseract-ios
  • Tesseract-OCR-iOS
  • OCR-iOS-Example

Other AI

• Axiomatic - Swift unification framework for logic programming.
• Build Your Own Lisp In Swift
• Logician - Logic programming in Swift
• Swiftlog - A simple Prolog-like language implemented entirely in Swift.

Machine Learning Web APIs

• IBM Watson - Enable Cognitive Computing Features In Your App Using IBM Watson's Language, Vision, Speech and Data APIs.
  • Introducing the (beta) IBM Watson iOS SDK
• AlchemyAPI - Semantic Text Analysis APIs Using Natural Language Processing. Now part of IBM Watson.
• Microsoft Project Oxford
• Google Prediction engine
  • Objective-C API
• Google Translate API
• Google Cloud Vision API
• Amazon Machine Learning - Amazon ML is a cloud-based service for developers. It provides visualization tools to create machine learning models. Obtain predictions for application using APIs.
  • iOS developer guide.
  • iOS SDK
• PredictionIO - opensource machine learning server for developers and ML engineers. Built on Apache Spark, HBase and Spray.
  • Swift SDK
  • Tapster iOS Demo - This demo demonstrates how to use the PredictionIO Swift SDK to integrate an iOS app with a PredictionIO engine to make your mobile app more interesting.
  • Tutorial on using Swift with PredictionIO.
• Wit.AI - NLP API
• Yandex SpeechKit Text-to-speech and speech-to-text for Russian language. iOS SDK available.
• Abbyy OCR SDK
• Clarifai - deep learning web api for image captioning. iOS starter project
• MetaMind - deep learning web api for image captioning.
• Api.AI - Build intelligent speech interfaces for apps, devices, and web
• CloudSight.ai - deep learning web API for fine grained object detection or whole screen description, including natural language object captions. Objective-C API client is available.

Opensource ML Applications

Deep Learning

• DeepDreamer - Deep Dream application
• DeepDreamApp - Deep Dream Cordova app.
• Texture Networks, Lua implementation
• Feedforward style transfer, Lua implementation
• TensorFlow implementation of Neural Style
• Corrosion detection app
• ios_camera_object_detection - Realtime mobile visualize based Object Detection based on TensorFlow and YOLO model
• TensorFlow MNIST iOS demo - Getting Started with Deep MNIST and TensorFlow on iOS
• Drummer App with RNN and Swift
• What'sThis
• enVision - Deep Learning Models for Vision Tasks on iOS\
• GoogLeNet on iOS demo
• Neural style in Android
• mnist-bnns - TensorFlow MNIST demo port to BNNS
• Benchmark of BNNS vs. MPS
• VGGNet on Metal
• A Sudoku Solver that leverages TensorFlow and iOS BNNS for deep learning.
• HED CoreML Implementation is a demo with tutorial on how to use Holistically-Nested Edge Detection on iOS with CoreML and Swift

Traditional Computer Vision

• SwiftOCR
• GrabCutIOS - Image segmentation using GrabCut algorithm for iOS

NLP

• Classical ELIZA chatbot in Swift
• InfiniteMonkeys - A Keras-trained RNN to emulate the works of a famous poet, powered by BrainCore

Other

• Swift implementation of Joel Grus's "Data Science from Scratch"
• Neural Network built in Apple Playground using Swift

Game AI

• Introduction to AI Programming for Games
• dlib is a library which has many useful tools including machine learning.
• MicroPather is a path finder and A* solver (astar or a-star) written in platform independent C++ that can be easily integrated into existing code.
• Here is a list of some AI libraries suggested on OGRE3D website. Seems they are mostly written in C++.
• GameplayKit Programming Guide

Other related staff

Linear algebra

• Accelerate-in-Swift - Swift example codes for the Accelerate.framework
• cuda-swift - Swift binding to CUDA. Not iOS, but still interesting.
• Dimensional - Swift matrices with friendly semantics and a familiar interface.
• Eigen - A high-level C++ library of template headers for linear algebra, matrix and vector operations, numerical solvers and related algorithms. [MPL2]
• Matrix - convenient matrix type with different types of subscripts, custom operators and predefined matrices. A fork of Surge.
• NDArray - Float library for Swift, accelerated with Accelerate Framework.
• Swift-MathEagle - A general math framework to make using math easy. Currently supports function solving and optimisation, matrix and vector algebra, complex numbers, big int, big frac, big rational, graphs and general handy extensions and functions.
• SwiftNum - linear algebra, fft, gradient descent, conjugate GD, plotting.
• Swix - Swift implementation of NumPy and OpenCV wrapper.
• Surge from Mattt
• Upsurge - generic tensors, matrices on top of Accelerate. A fork of Surge.
• YCMatrix - A flexible Matrix library for Objective-C and Swift (OS X / iOS)

Statistics, random numbers

• SigmaSwiftStatistics - A collection of functions for statistical calculation written in Swift.
• SORandom - Collection of functions for generating psuedorandom variables from various distributions
• RandKit - Swift framework for random numbers & distributions.

Mathematical optimization

• fmincg-c - Conjugate gradient implementation in C
• libLBFGS - a C library of Limited-memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS)
• SwiftOptimizer - QuantLib Swift port.

Feature extraction

• IntuneFeatures framework contains code to generate features from audio files and feature labels from the respective MIDI files.
• matchbox - Mel-Frequency-Cepstral-Coefficients and Dynamic-Time-Warping for iOS/OSX. Warning: the library was updated last time when iOS 4 was still hot.
• LibXtract is a simple, portable, lightweight library of audio feature extraction functions.

Data Visualization

• Charts - The Swift port of the MPAndroidChart.
• iOS-Charts
• Core Plot
• Awesome iOS charts
• JTChartView
• VTK
  • VTK in action
• D3.js iOS binding

Bioinformatics (kinda)

• BioJS - a set of tools for bioinformatics in the browser. BioJS builds a infrastructure, guidelines and tools to avoid the reinvention of the wheel in life sciences. Community builds modules than can be reused by anyone.
• BioCocoa - BioCocoa is an open source OpenStep (GNUstep/Cocoa) framework for bioinformatics written in Objective-C. [Dead project].
• iBio - A Bioinformatics App for iPhone.

Big Data (not really)

• HDF5Kit - This is a Swift wrapper for the HDF5 file format. HDF5 is used in the scientific comunity for managing large volumes of data. The objective is to make it easy to read and write HDF5 files from Swift, including playgrounds.

IPython + Swift

• iSwift - Swift kernel for IPython notebook.

iOS ML Blogs

Regular mobile ML

• The "Machine, think!" blog by Matthijs Hollemans
  • The “hello world” of neural networks - Swift and BNNS
  • Convolutional neural networks on the iPhone with VGGNet
• Pete Warden's blog
  • How to Quantize Neural Networks with TensorFlow

Accidental mobile ML

• Google research blog
• Apple Machine Learning Journal
• Invasive Code blog
  • Machine Learning for iOS
  • Convolutional Neural Networks in iOS 10 and macOS
• Big Nerd Ranch - Use TensorFlow and BNNS to Add Machine Learning to your Mac or iOS App

Other

• Intelligence in Mobile Applications
• An exclusive inside look at how artificial intelligence and machine learning work at Apple
• Presentation on squeezing DNNs for mobile
• Curated list of papers on deep learning models compression and acceleration

GPU Computing Blogs

• OpenCL for iOS - just a test.

• Exploring GPGPU on iOS.

  • Article
  • Code

• GPU-accelerated video processing for Mac and iOS. Article.

• Concurrency and OpenGL ES - Apple programming guide.

• OpenCV on iOS GPU usage - SO discussion.

Metal

• Simon's Gladman (aka flexmonkey) blog
  • Talk on iOS GPU programming with Swift and Metal at Realm Altconf.
  • The Supercomputer In Your Pocket: Metal & Swift - a video from the Swift Summit Conference 2015
  • https://github.com/FlexMonkey/MetalReactionDiffusion
  • https://github.com/FlexMonkey/ParticleLab
• Memkite blog - startup intended to create deep learning library for iOS.
  • Swift and Metal example for General Purpose GPU Processing on Apple TVOS 9.0
  • Data Parallel Processing with Swift and Metal on GPU for iOS8
  • Example of Sharing Memory between GPU and CPU with Swift and Metal for iOS8
• Metal by Example blog
• objc-io article on Metal

Mobile ML Books

• Building Mobile Applications with TensorFlow by Pete Warden. Book page. Free download

Learn Machine Learning

Please note that in this section, I'm not trying to collect another list of ALL machine learning study resources, but only composing a list of things that I found useful.

• Academic Torrents. Sometimes awesome courses or datasets got deleted from their sites. But this doesn't mean, that they are lost.
• Arxiv Sanity Preserver - a tool to keep pace with the ML research progress.

Free Books

• Immersive Linear Algebra interactive book by J. Ström, K. Åström, and T. Akenine-Möller.
• "Natural Language Processing with Python" - free online book.
• Probabilistic Programming & Bayesian Methods for Hackers - An intro to Bayesian methods and probabilistic programming from a computation/understanding-first, mathematics-second point of view.
• "Deep learning" - the book by Ian Goodfellow and Yoshua Bengio and Aaron Courville

Free Courses

• Original Machine Learning Coursera course by Andrew Ng.
• Machine learning playlist on Youtube.
• Free online interactive book "Neural Networks and Deep Learning".
• Heterogeneous Parallel Programming course.
• Deep Learning for Perception by Virginia Tech, Electrical and Computer Engineering, Fall 2015: ECE 6504
• CAP 5415 - Computer Vision by UCF
• CS224d: Deep Learning for Natural Language Processing by Stanford
• Machine Learning: 2014-2015 Course materials by Oxford
• Stanford CS class CS231n: Convolutional Neural Networks for Visual Recognition.
• Deep Learning for Natural Language Processing (without Magic)
• Videos from Deep Learning Summer School, Montreal 2015.
• Deep Learning Summer School, Montreal 2016

Other Lists

• Awesome Machine Learning
• Machine Learning Courses
• Awesome Data Science
• Awesome Computer Vision
• Speech and language processing
• The Rise of Chat Bots: Useful Links, Articles, Libraries and Platforms by Pavlo Bashmakov.
• Awesome Machine Learning for Cyber Security