Tag Archives: ML

ML Kit Pose Detection Makes Staying Active at Home Easier

Posted by Kenny Sulaimon, Product Manager, ML Kit; Chengji Yan and Areeba Abid, Software Engineers, ML Kit

ML Kit logo

Two months ago we introduced the standalone version of the ML Kit SDK, making it even easier to integrate on-device machine learning into mobile apps. Since then we’ve launched the Digital Ink Recognition API, and also introduced the ML Kit early access program. Our first two early access APIs were Pose Detection and Entity Extraction. We’ve received an overwhelming amount of interest in these new APIs and today, we are thrilled to officially add Pose Detection to the ML Kit lineup.

ML Kit Overview

A New ML Kit API, Pose Detection


Examples of ML Kit Pose Detection

ML Kit Pose Detection is an on-device, cross platform (Android and iOS), lightweight solution that tracks a subject's physical actions in real time. With this technology, building a one-of-a-kind experience for your users is easier than ever.

The API produces a full body 33 point skeletal match that includes facial landmarks (ears, eyes, mouth, and nose), along with hands and feet tracking. The API was also trained on a variety of complex athletic poses, such as Yoga positions.

Skeleton image detailing all 33 landmark points

Skeleton image detailing all 33 landmark points

Under The Hood

Diagram of the ML Kit Pose Detection Pipeline

The power of the ML Kit Pose Detection API is in its ease of use. The API builds on the cutting edge BlazePose pipeline and allows developers to build great experiences on Android and iOS, with little effort. We offer a full body model, support for both video and static image use cases, and have added multiple pre and post processing improvements to help developers get started with only a few lines of code.

The ML Kit Pose Detection API utilizes a two step process for detecting poses. First, the API combines an ultra-fast face detector with a prominent person detection algorithm, in order to detect when a person has entered the scene. The API is capable of detecting a single (highest confidence) person in the scene and requires the face of the user to be present in order to ensure optimal results.

Next, the API applies a full body, 33 landmark point skeleton to the detected person. These points are rendered in 2D space and do not account for depth. The API also contains a streaming mode option for further performance and latency optimization. When enabled, instead of running person detection on every frame, the API only runs this detector when the previous frame no longer detects a pose.

The ML Kit Pose Detection API also features two operating modes, “Fast” and “Accurate”. With the “Fast” mode enabled, you can expect a frame rate of around 30+ FPS on a modern Android device, such as a Pixel 4 and 45+ FPS on a modern iOS device, such as an iPhone X. With the “Accurate” mode enabled, you can expect more stable x,y coordinates on both types of devices, but a slower frame rate overall.

Lastly, we’ve also added a per point “InFrameLikelihood” score to help app developers ensure their users are in the right position and filter out extraneous points. This score is calculated during the landmark detection phase and a low likelihood score suggests that a landmark is outside the image frame.

Real World Applications


Examples of a pushup and squat counter using ML Kit Pose Detection

Keeping up with regular physical activity is one of the hardest things to do while at home. We often rely on gym buddies or physical trainers to help us with our workouts, but this has become increasingly difficult. Apps and technology can often help with this, but with existing solutions, many app developers are still struggling to understand and provide feedback on a user’s movement in real time. ML Kit Pose Detection aims to make this problem a whole lot easier.

The most common applications for Pose detection are fitness and yoga trackers. It’s possible to use our API to track pushups, squats and a variety of other physical activities in real time. These complex use cases can be achieved by using the output of the API, either with angle heuristics, tracking the distance between joints, or with your own proprietary classifier model.

To get you jump started with classifying poses, we are sharing additional tips on how to use angle heuristics to classify popular yoga poses. Check it out here.

Learning to Dance Without Leaving Home

Learning a new skill is always tough, but learning to dance without the aid of a real time instructor is even tougher. One of our early access partners, Groovetime, has set out to solve this problem.

With the power of ML Kit Pose Detection, Groovetime allows users to learn their favorite dance moves from popular short-form dance videos, while giving users automated real time feedback on their technique. You can join their early access beta here.

Groovetime App using ML Kit Pose Detection

Staying Active Wherever You Are

Our Pose Detection API is also helping adidas Training, another one of our early access partners, build a virtual workout experience that will help you stay active no matter where you are. This one-of-a-kind innovation will help analyze and give feedback on the user’s movements, using nothing more than just your phone. Integration into the adidas Training app is still in the early phases of the development cycle, but stay tuned for more updates in the future.

How to get started?

If you would like to start using the Pose Detection API in your mobile app, head over to the developer documentation or check out the sample apps for Android and iOS to see the API in action. For questions or feedback, please reach out to us through one of our community channels.

Digital Ink Recognition in ML Kit

Posted by Mircea Trăichioiu, Software Engineer, Handwriting Recognition

A month ago, we announced changes to ML Kit to make mobile development with machine learning even easier. Today we're announcing the addition of the Digital Ink Recognition API on both Android and iOS to allow developers to create apps where stylus and touch act as first class inputs.

Digital ink recognition: the latest addition to ML Kit’s APIs

Digital Ink Recognition is different from the existing Vision and Natural Language APIs in ML Kit, as it takes neither text nor images as input. Instead, it looks at the user's strokes on the screen and recognizes what they are writing or drawing. This is the same technology that powers handwriting recognition in Gboard - Google’s own keyboard app, which we described in detail in a 2019 blog post. It's also the same underlying technology used in the Quick, Draw! and AutoDraw experiments.

Handwriting input in Gboard

Turning doodles into art with Autodraw

With the new Digital Ink Recognition API, developers can now use this technology in their apps as well, for everything from letting users input text and figures with a finger or stylus to transcribing handwritten notes to make them searchable; all in near real time and entirely on-device.

Supports many languages and character sets

Digital Ink Recognition supports 300+ languages and 25+ writing systems including all major Latin languages, as well as Chinese, Japanese, Korean, Arabic, Cyrillic, and more. Classifiers parse written text into a string of characters

Recognizes shapes

Other classifiers can describe shapes, such as drawings and emojis, by the class to which they belong (circle, square, happy face, etc). We currently support an autodraw sketch recognizer, an emoji recognizer, and a basic shape recognizer.

Works offline

Digital Ink Recognition API runs on-device and does not require a network connection. However, you must download one or more models before you can use a recognizer. Models are downloaded on demand and are around 20MB in size. Refer to the model download documentation for more information.

Runs fast

The time to perform a recognition call depends on the exact device and the size of the input stroke sequence. On a typical mobile device recognizing a line of text takes about 100 ms.

How to get started

If you would like to start using Digital Ink Recognition in your mobile app, head over to the documentation or check out the sample apps for Android and iOS to see the API in action. For questions or feedback, please reach out to us through one of our community channels.

Full spectrum of on-device machine learning tools on Android

Posted by Hoi Lam, Android Machine Learning



This blog post is part of a weekly series for #11WeeksOfAndroid. Each week we’re diving into a key area of Android so you don’t miss anything. Throughout this week, we covered various aspects of Android on-device machine learning (ML). Whichever stage of development be it starting out or an established app; whatever role you play in design, product and engineering; whatever your skill level from beginner to experts, we have a wide range of ML tools for you.

Design - ML as a differentiator

“Focus on the user and all else will follow” is a Google mantra that becomes even more relevant in our machine learning age. Our Design Advocate, Di Dang, highlighted the importance of finding the unique intersection of user problems and ML strengths. Too often, teams are so keen on the idea of machine learning that they lose sight of their user needs.



Di outlined how the People + AI Guidebook can help you make ML product decisions and used the example of the Read Along app to illustrate topics like precision and recall, which are unique to ML design and development. Check out her interview with the Read Along team together with your team for more inspiration.

New ML Kit fully focused on on-device

When you decide that on-device machine learning is the solution, the easiest way to implement it will be through turnkey SDKs like ML Kit. Sophisticated Google-trained models and processing pipelines are offered through an easy to use interface in Kotlin / Java. ML Kit is designed and built for on-device ML: it works offline, offers enhanced privacy, unlocks high performance for real-time use cases and it is free. We recently made ML Kit a standalone SDK and it no longer requires a Firebase account. Just one line in your build.gradle file and you can start bringing ML functionality into your app.



The team has also added new functionalities such as Jetpack lifecycle support and the option to use the face contour models via Google Play Services saving as much as 20MB in app size. Another much anticipated addition is the support for swapping Google models with your own for both Image Labeling as well as Object Detection and Tracking. This provides one of the easiest ways to add TensorFlow Lite models to your applications without interacting with ByteArray!

Customise with TensorFlow Lite and Android tools

If the base model provided by ML Kit doesn’t quite fit the bill, what should developers do? The first port of call should be TensorFlow Hub where ready-to-use TensorFlow Lite models from both Google and the wider community can be downloaded. From 100,000 US Supermarket products to tomato plant diseases classifiers, the choice is yours.



In addition to Firebase AutoML Vision Edge, you can also build your own model using TensorFlow Model Maker (image classification / text classification) with just a few lines of Python. Once you have a TensorFlow Lite model from either TensorFlow Hub, or the Model Maker, you can easily integrate it with your Android app using ML Kit Image Labelling or Object Detection and Tracking. If you prefer an open source solution, Android Studio 4.1 beta introduces ML model binding that helps wrap around the TensorFlow Lite model with an easy to use Kotlin / Java wrapper. Adding a custom model to your Android app has never been easier. Check out this blog for more details.

Time for on-device ML is now

From the examples of the Android Developer Challenge winners, it is obvious that on-device machine learning has come of age and ML functionalities once reserved for the cloud or supercomputers are now available on your Android phone. Take a step forward with us by trying out our codelabs of the day:

Also checkout the ML Week learning pathway and take the quiz to get your very own ML badge.

Android on-device machine learning is a rapidly evolving platform, if you have any enhancement requests or feedback on how it could be improved, please let us know together with your use-case (TensorFlow Lite / ML Kit). Time for on-device ML is now.

Resources

You can find the entire playlist of #11WeeksOfAndroid video content here, and learn more about each week here. We’ll continue to spotlight new areas each week, so keep an eye out and follow us on Twitter and YouTube. Thanks so much for letting us be a part of this experience with you!

New tools for finding, training, and using custom machine learning models on Android

Posted by Hoi Lam, Android Machine Learning

Yesterday, we talked about turnkey machine learning (ML) solutions with ML Kit. But what if that doesn’t completely address your needs and you need to tweak it a little? Today, we will discuss how to find alternative models, and how to train and use custom ML models in your Android app.

Find alternative ML models

Crop disease models from the wider research community available on tfhub.dev

If the turnkey ML solutions don't suit your needs, TensorFlow Hub should be your first port of call. It is a repository of ML models from Google and the wider research community. The models on the site are ready for use in the cloud, in a web-browser or in an app on-device. For Android developers, the most exciting models are the TensorFlow Lite (TFLite) models that are optimized for mobile.

In addition to key vision models such as MobileNet and EfficientNet, the repository also boast models powered by the latest research such as:

Many of these solutions were previously only available in the cloud, as the models are too large and too power intensive to run on-device. Today, you can run them on Android on-device, offline and live.

Train your own custom model

Besides the large repository of base models, developers can also train their own models. Developer-friendly tools are available for many common use cases. In addition to Firebase’s AutoML Vision Edge, the TensorFlow team launched TensorFlow Lite Model Maker earlier this year to give developers more choices over the base model that support more use cases. TensorFlow Lite Model Maker currently supports two common ML tasks:

The TensorFlow Lite Model Maker can run on your own developer machine or in Google Colab online machine learning notebooks. Going forward, the team plans to improve the existing offerings and to add new use cases.

Using custom model in your Android app

New TFLite Model import screen in Android Studio 4.1 beta

Once you have selected a model or trained your model there are new easy-to-use tools to help you integrate them into your Android app without having to convert everything into ByteArrays. The first new tool is ML Model binding with Android Studio 4.1. This lets developers import any TFLite model, read the input / output signature of the model, and use it with just a few lines of code that calls the open source TensorFlow Lite Android Support Library.

Another way to implement a TensorFlow Lite model is via ML Kit. Starting in June, ML Kit no longer requires a Firebase project for on-device functionality. In addition, the image classification and object detection and tracking (ODT) APIs support custom models. The latter ODT offering is especially useful in use-cases where you need to separate out objects from a busy scene.

So how should you choose between these three solutions? If you are trying to detect a product on a busy supermarket shelf, ML Kit object detection and tracking can help your user select a specific product for processing. The API then performs image classification on just the part of the image that contains the product, which results in better detection performance. On the other hand, if the scene or the object you are trying to detect takes up most of the input image, for example, a landmark such as Big Ben, using ML Model binding or the ML Kit image classification API might be more appropriate.

TensorFlow Hub bird detection model with ML Kit Object Detection & Tracking AP

Two examples of how these tools can fit together

Here are some resources to help you get started:

Customizing your model is easier than ever

Finding, building and using custom models on Android has never been easier. As both Android and TensorFlow teams increase the coverage of machine learning use cases, please let us know how we can improve these tools for your use cases by filing an enhancement request with TensorFlow Lite or ML Kit.

Tomorrow, we will take a step back and focus on how to appropriately use and design for a machine learning first Android app. The content will be appropriate for the entire development team, so bring your product manager and designers along. See you next time.

On-device machine learning solutions with ML Kit, now even easier to use

Posted by Christiaan Prins, Product Manager, ML Kit and Shiyu Hu, Tech Lead Manager, ML Kit

ML Kit logo

Two years ago at I/O 2018 we introduced ML Kit, making it easier for mobile developers to integrate machine learning into your apps. Today, more than 25,000 applications on Android and iOS make use of ML Kit’s features. Now, we are introducing some changes that will make it even easier to use ML Kit. In addition, we have a new feature and a set of improvements we’d like to discuss.

A new ML Kit SDK, fully focused on on-device ML

ML Kit API Overview

ML Kit's APIs are built to help you tackle common challenges in the Vision and Natural Language domains. We make it easy to recognize text, scan barcodes, track and classify objects in real-time, do translation of text, and more.

The original version of ML Kit was tightly integrated with Firebase, and we heard from many of you that you wanted more flexibility when implementing it in your apps. As a result, we are now making all the on-device APIs available in a new standalone ML Kit SDK that no longer requires a Firebase project. You can still use both ML Kit and Firebase to get the best of both products if you choose to.

With this change, ML Kit is now fully focused on on-device machine learning, giving you access to the unique benefits that on-device versus cloud ML offers:

  • It’s fast, unlocking real-time use cases- since processing happens on the device, there is no network latency. This means, we can do inference on a stream of images / video or multiple times a second on text strings.
  • Works offline - you can rely on our APIs even when the network is spotty or your app’s end-user is in an area without connectivity.
  • Privacy is retained: since all processing is performed locally, there is no need to send sensitive user data over the network to a server.

Naturally, you still get access to Google’s on-device models and processing pipelines, all accessible through easy-to-use APIs, and offered at no cost.

All ML Kit resources can now be found on our new website where we made it a lot easier to access sample apps, API reference docs and our community channels that are there to help you if you have questions.

Object detection & tracking gif Text recognition + Language ID + Translate gif

What does this mean if I already use ML Kit today?

If you are using ML Kit for Firebase’s on-device APIs in your app today, we recommend you to migrate to the new standalone ML Kit SDK to benefit from new features and updates. For more information and step-by-step instructions to update your app, please follow our Migration guide. The cloud-based APIs, model deployment and AutoML Vision Edge remain available through Firebase Machine Learning.

Shrink your app footprint with Google Play Services

Apart from making ML Kit easier to use, developers also asked if we can ship ML Kit through Google Play Services resulting in a smaller app footprint and the model can be reused between apps. Apart from Barcode scanning and Text recognition, we have now added Face detection / contour (model size: 20MB) to the list of APIs that support this functionality.

// Face detection / Face contour model
// Delivered via Google Play Services outside your app's APK…
implementation 'com.google.android.gms:play-services-mlkit-face-detection:16.0.0'

// …or bundled with your app's APK
implementation 'com.google.mlkit:face-detection:16.0.0'

Jetpack Lifecycle / CameraX support

Android Jetpack Lifecycle support has been added to all APIs. Developers can use addObserver to automatically manage teardown of ML Kit APIs as the app goes through screen rotation or closure by the user / system. This makes CameraX integration easier. With this release, we are also recommending that developers adopt CameraX in their apps due to the ease of integration and image quality improvements (compared to Camera1) on a wide range of devices.

// ML Kit now supports Lifecycle
val recognizer = TextRecognizer.newInstance()
lifecycle.addObserver(recognizer)

// ...

// Just like CameraX
val camera = cameraProvider.bindToLifecycle( /* lifecycleOwner= */this,
    cameraSelector, previewUseCase, analysisUseCase)

For an overview of all recent changes, check out the release notes for the new SDK.

Codelab of the day - ML Kit x CameraX

To help you get started with the new ML Kit and its support for CameraX, we have created this code lab to Recognize, Identify Language and Translate text. If you have any questions regarding this code lab, please raise them at StackOverflow and tag it with [google-mlkit]. Our team will monitor this.

screenshot of app running

Early access program

Through our early access program, developers have an opportunity to partner with the ML Kit team and get access to upcoming features. Two new APIs are now available as part of this program:

  • Entity Extraction - Detect entities in text & make them actionable. We have support for phone numbers, addresses, payment numbers, tracking numbers, date/time and more.
  • Pose Detection - Low-latency pose detection supporting 33 skeletal points, including hands and feet tracking.

If you are interested, head over to our early access page for details.

pose detection on man jumping rope

Tomorrow - Support for custom models

ML Kit's turn-key solutions are built to help you take common challenges. However, if you needed to have a more tailored solution, one that required custom models, you typically needed to build an implementation from scratch. To help, we are now providing the option to swap out the default Google models with a custom TensorFlow Lite model. We’re starting with the Image Labeling and Object Detection and Tracking APIs, that now support custom image classification models.

Tomorrow, we will dive a bit deeper into how to find or train a TensorFlow Lite model and use it either with ML Kit, or with Android Studio’s new ML binding functionality.

On-device machine learning solutions with ML Kit, now even easier to use

Posted by Christiaan Prins, Product Manager, ML Kit and Shiyu Hu, Tech Lead Manager, ML Kit

ML Kit logo

Two years ago at I/O 2018 we introduced ML Kit, making it easier for mobile developers to integrate machine learning into your apps. Today, more than 25,000 applications on Android and iOS make use of ML Kit’s features. Now, we are introducing some changes that will make it even easier to use ML Kit. In addition, we have a new feature and a set of improvements we’d like to discuss.

A new ML Kit SDK, fully focused on on-device ML

ML Kit API Overview

ML Kit's APIs are built to help you tackle common challenges in the Vision and Natural Language domains. We make it easy to recognize text, scan barcodes, track and classify objects in real-time, do translation of text, and more.

The original version of ML Kit was tightly integrated with Firebase, and we heard from many of you that you wanted more flexibility when implementing it in your apps. As a result, we are now making all the on-device APIs available in a new standalone ML Kit SDK that no longer requires a Firebase project. You can still use both ML Kit and Firebase to get the best of both products if you choose to.

With this change, ML Kit is now fully focused on on-device machine learning, giving you access to the unique benefits that on-device versus cloud ML offers:

  • It’s fast, unlocking real-time use cases- since processing happens on the device, there is no network latency. This means, we can do inference on a stream of images / video or multiple times a second on text strings.
  • Works offline - you can rely on our APIs even when the network is spotty or your app’s end-user is in an area without connectivity.
  • Privacy is retained: since all processing is performed locally, there is no need to send sensitive user data over the network to a server.

Naturally, you still get access to Google’s on-device models and processing pipelines, all accessible through easy-to-use APIs, and offered at no cost.

All ML Kit resources can now be found on our new website where we made it a lot easier to access sample apps, API reference docs and our community channels that are there to help you if you have questions.

Object detection & tracking gif Text recognition + Language ID + Translate gif

What does this mean if I already use ML Kit today?

If you are using ML Kit for Firebase’s on-device APIs in your app today, we recommend you to migrate to the new standalone ML Kit SDK to benefit from new features and updates. For more information and step-by-step instructions to update your app, please follow our Migration guide. The cloud-based APIs, model deployment and AutoML Vision Edge remain available through Firebase Machine Learning.

Shrink your app footprint with Google Play Services

Apart from making ML Kit easier to use, developers also asked if we can ship ML Kit through Google Play Services resulting in a smaller app footprint and the model can be reused between apps. Apart from Barcode scanning and Text recognition, we have now added Face detection / contour (model size: 20MB) to the list of APIs that support this functionality.

// Face detection / Face contour model
// Delivered via Google Play Services outside your app's APK…
implementation 'com.google.android.gms:play-services-mlkit-face-detection:16.0.0'

// …or bundled with your app's APK
implementation 'com.google.mlkit:face-detection:16.0.0'

Jetpack Lifecycle / CameraX support

Android Jetpack Lifecycle support has been added to all APIs. Developers can use addObserver to automatically manage teardown of ML Kit APIs as the app goes through screen rotation or closure by the user / system. This makes CameraX integration easier. With this release, we are also recommending that developers adopt CameraX in their apps due to the ease of integration and image quality improvements (compared to Camera1) on a wide range of devices.

// ML Kit now supports Lifecycle
val recognizer = TextRecognizer.newInstance()
lifecycle.addObserver(recognizer)

// ...

// Just like CameraX
val camera = cameraProvider.bindToLifecycle( /* lifecycleOwner= */this,
    cameraSelector, previewUseCase, analysisUseCase)

For an overview of all recent changes, check out the release notes for the new SDK.

Codelab of the day - ML Kit x CameraX

To help you get started with the new ML Kit and its support for CameraX, we have created this code lab to Recognize, Identify Language and Translate text. If you have any questions regarding this code lab, please raise them at StackOverflow and tag it with [google-mlkit]. Our team will monitor this.

screenshot of app running

Early access program

Through our early access program, developers have an opportunity to partner with the ML Kit team and get access to upcoming features. Two new APIs are now available as part of this program:

  • Entity Extraction - Detect entities in text & make them actionable. We have support for phone numbers, addresses, payment numbers, tracking numbers, date/time and more.
  • Pose Detection - Low-latency pose detection supporting 33 skeletal points, including hands and feet tracking.

If you are interested, head over to our early access page for details.

pose detection on man jumping rope

Tomorrow - Support for custom models

ML Kit's turn-key solutions are built to help you take common challenges. However, if you needed to have a more tailored solution, one that required custom models, you typically needed to build an implementation from scratch. To help, we are now providing the option to swap out the default Google models with a custom TensorFlow Lite model. We’re starting with the Image Labeling and Object Detection and Tracking APIs, that now support custom image classification models.

Tomorrow, we will dive a bit deeper into how to find or train a TensorFlow Lite model and use it either with ML Kit, or with Android Studio’s new ML binding functionality.

13 Most Common Google Cloud Reference Architectures

Posted by Priyanka Vergadia, Developer Advocate

Google Cloud is a cloud computing platform that can be used to build and deploy applications. It allows you to take advantage of the flexibility of development while scaling the infrastructure as needed.

I'm often asked by developers to provide a list of Google Cloud architectures that help to get started on the cloud journey. Last month, I decided to start a mini-series on Twitter called “#13DaysOfGCP" where I shared the most common use cases on Google Cloud. I have compiled the list of all 13 architectures in this post. Some of the topics covered are hybrid cloud, mobile app backends, microservices, serverless, CICD and more. If you were not able to catch it, or if you missed a few days, here we bring to you the summary!

Series kickoff #13DaysOfGCP

#1: How to set up hybrid architecture in Google Cloud and on-premises

Day 1

#2: How to mask sensitive data in chatbots using Data loss prevention (DLP) API?

Day 2

#3: How to build mobile app backends on Google Cloud?

Day 3

#4: How to migrate Oracle Database to Spanner?

Day 4

#5: How to set up hybrid architecture for cloud bursting?

Day 5

#6: How to build a data lake in Google Cloud?

Day 6

#7: How to host websites on Google Cloud?

Day 7

#8: How to set up Continuous Integration and Continuous Delivery (CICD) pipeline on Google Cloud?

Day 8

#9: How to build serverless microservices in Google Cloud?

Day 9

#10: Machine Learning on Google Cloud

Day 10

#11: Serverless image, video or text processing in Google Cloud

Day 11

#12: Internet of Things (IoT) on Google Cloud

Day 12

#13: How to set up BeyondCorp zero trust security model?

Day 13

Wrap up with a puzzle

Wrap up!

We hope you enjoy this list of the most common reference architectures. Please let us know your thoughts in the comments below!

Machine Learning-based Damage Assessment for Disaster Relief



Natural disasters, such as earthquakes, hurricanes, and floods, affect large areas and millions of people, but responding to such disasters is a massive logistical challenge. Crisis responders, including governments, NGOs, and UN organizations, need fast access to comprehensive and accurate assessments in the aftermath of disasters to plan how best to allocate limited resources.To this end, very high resolution (VHR) satellite imagery, with up to 0.3 meter resolution, is becoming an increasingly important tool for crisis response, giving responders an unprecedented breadth of visual information about how terrain, infrastructure, and populations are changed by disasters.

However, intensive manual labor is still required to extract operationally-relevant information — collapsed buildings, cracks in bridges, where people have set up temporary shelters — from the raw satellite imagery. As an example, for the 2010 Haiti earthquake, analysts manually examined over 90,000 buildings in the Port-au-Prince area alone, rating the damage each one incurred on a five point scale. Many of these manual analyses take teams of experts many weeks to complete, whereas they are most needed within 48-72 hours after the disaster, when the most urgent decisions are made.

To help mitigate the impact of such disasters, we present "Building Damage Detection in Satellite Imagery Using Convolutional Neural Networks", which details a machine learning (ML) approach to automatically process satellite data to generate building damage assessments. Developed in partnership with the United Nations World Food Program (WFP) Innovation Accelerator, we believe this work has the potential to drastically reduce the time and effort required for crisis workers to produce damage assessment reports. In turn, this would reduce the turnaround times needed to deliver timely disaster aid to the most severely affected areas, while increasing the overall coverage of such critical services.

The Approach
The automatic damage assessment process is split into two steps: building detection and damage classification. In the building detection step, our approach uses an object detection model to draw bounding boxes around each building in the image. We then extract pre-disaster and post-disaster images centered on each detected building and use a classification model to determine whether the building is damaged.

The classification model consists of a convolutional neural network to which is input two 161 pixel x 161 pixel RGB images, corresponding to a 50 m x 50 m ground footprint, centered on a given building. One image is from before the disaster event, and the other image is from after the disaster event. The model analyzes differences in the two images and outputs a score from 0.0 to 1.0, where 0.0 means the building was not damaged, and 1.0 means the building was damaged.

Because the before and after images are taken on different dates, at different times of day, and in some cases by different satellites altogether, there can be a host of different problems that arise. For example, the brightness, contrast, color saturation, and lighting conditions of the images may differ significantly, and the pixels in the image may be misaligned.

To correct for differences in color and illumination, we use histogram equalization to normalize the colors in the before and after images. We also make the model more robust to insignificant color differences by using standard data augmentation techniques, such as randomly perturbing the contrast and saturation of the images, during training.

Training Data
One of the main challenges of this work is assembling a training data set. Data availability in this application is inherently limited because there are only a handful of disasters that have high resolution satellite images and an even smaller number that have existing damage assessments. For labels, we use publicly available damage assessments manually generated by humanitarian organizations operating in this space, such as UNOSAT and REACH. We obtain the original satellite images on which the manual assessments are performed and then use Google Earth Engine to spatially join the damage assessment labels with the satellite images in order to produce the final training examples. All images used to train the model were sourced from commercially available sources.
Examples of individual image patches that capture before and after images of damaged and undamaged buildings from different disasters.
Results
We evaluated this technology for 3 major past earthquakes: the 2010 earthquake in Haiti (magnitude 7.0), the 2017 event in Mexico City (magnitude 7.1), and the series of earthquakes occuring in Indonesia in 2018 (magnitudes 5.9 - 7.5). For each event, we trained the model on buildings in one part of the region affected by the quake and tested it on buildings in another part of the region. We used human expert damage assessments performed by UNOSAT and REACH as the ground truth for evaluation. We measure the model’s quality using both true accuracy (compared to expert assessment) and the area under the ROC curve (AUROC), which captures the trade-off between the model’s true positive and false positive rates of detection, and is a common way to measure quality when the number of positive and negative examples in the test dataset is imbalanced. An AUROC value of 0.5 means that the model’s predictions are random, while a value of 1.0 means the model is perfectly accurate. According to crisis responder feedback, 70% accuracy is the threshold needed for making high-level decisions in the first 72 hours after the disaster.
Area under the
Event Accuracy ROC curve
2010 Haiti earthquake 77% 0.83
2017 Mexico City earthquake 71% 0.79
2018 Indonesia earthquake 78% 0.86
Evaluation of model predictions against human expert assessments (higher is better).
Example model predictions from the 2010 Haiti earthquake. Prediction values closer to 1.0 means the model is more confident that the building is damaged. Values closer to 0.0 means the building is not damaged. A threshold value of 0.5 is typically used to distinguish between damaged/undamaged predictions, but this can be tuned to make the predictions more or less sensitive.
Future Work
While the current model works reasonably well when trained and tested on buildings from the same regions (e.g., same city or country), the ultimate goal is to have a model that can accurately assess building damage for disasters that happen anywhere in the world, and not just those that look similar to the ones the model has been trained on. This is challenging because the variety of the available training data for past disasters is inherently limited to a handful of events that occurred in a few geographic locations. Generalizing to future disasters that will likely occur in new locations is therefore still a challenge for our model and is the focus of ongoing work. We envision a system that can be interactively trained, validated, and deployed by expert analysts so that important aid distribution decisions are always verified by experienced crisis responders. Our hope is that this technology can help communities get the aid that they need in times of most critical need in a timely fashion.

Acknowledgements
This post reflects the work of our co-authors Wenhan Lu and Zebo Li. We would also like to thank Maolin Zuo for his contributions to the project. In tackling this problem, we have had a very productive partnership with the United Nations World Food Programme (WFP) Innovation Accelerator, an organization that identifies, funds, and supports startups and innovative projects to disrupt world hunger.

Source: Google AI Blog


Free Universal Sound Separation

We are happy to announce the release of FUSS: the Free Universal Sound Separation dataset.

Audio recordings often contain a mixture of different sound sources; Universal sound separation is the ability to separate such a mixture into its component sounds, regardless of the types of sound present. Previously, sound separation work has focused on separating mixtures of a small number of sound types, such as "speech" versus "nonspeech", or different instances of the same type of sound, such as speaker #1 versus speaker #2. Often in such work, the number of sounds in a mixture is also assumed to be known a priori. The FUSS dataset shifts focus to the more general problem of separating a variable number of arbitrary sounds from one another.

One major hurdle to training models in this domain is that even if you have high-quality recordings of sound mixtures, you can't easily annotate these recordings with ground truth. High-quality simulation is one approach to overcome this limitation. To achieve good results, you need a diverse set of sounds, a realistic room simulator, and code to mix these elements together for realistic, multi-source, multi-class audio with ground truth. With FUSS, we are releasing all three of these.

FUSS relies on Creative Commons licensed audio clips from freesound.org. We filtered these by license type, then using a pre-release of FSD50k [1], further filtered out sounds that aren't separable by humans when mixed together. We were left with about 23 hours of audio, consisting of 12,377 sounds useful for mixing (7,237 train, 2,883 validation, 2,257 eval). Using these clips, we created 20,000 training mixtures, 1,000 validation mixtures, and 1,000 eval mixtures.

We developed our own room simulator implemented in tensorflow, which generates the impulse response of a box shaped room with frequency-dependent reflective properties given a sound source location and a mic location. As part of the dataset release, we provide pre-calculated room impulse responses used for each audio sample along with mixing code, so the research community can simulate novel audio without running the computationally expensive room simulator. Future work may include releasing the code for our room simulator and extending the simulator capabilities to address more extensive acoustic properties of rooms, materials with different reflective properties, novel room shapes, etc.

Finally, we have released a masking-based separation model, based on an improved time-domain convolutional network (TDCN++), described in our recent publications [2, 3]. On the eval set, this model achieves 12.5 dB of scale-invariant signal-to-noise ratio improvement (SI-SNRi) on mixtures with two to four sources, while reconstructing single-source mixtures with 37.6 dB absolute SI-SNR.

Source audio, reverb impulse responses, reverberated mixtures and sources created by the mixing code, and a baseline model checkpoint are available for download. Code for reverberating and mixing the audio data and for training the released model is available on our github page.

The dataset will also be used in the DCASE challenge, as a component of the Sound Event Detection and Separation task. The released model will serve as a baseline for this competition, and a benchmark to demonstrate progress against in future experiments.

Our hope is this dataset will lower the barrier to new research, and particularly will allow for fast iteration and application of novel techniques from other machine learning domains to the sound separation challenge.

By John Hershey, Scott Wisdom, and Hakan Erdogan, Google Research

References:
[1] Eduardo Fonseca, Jordi Pons, Xavier Favory, Frederic Font Corbera, Dmitry Bogdanov, Andrés Ferraro, Sergio Oramas, Alastair Porter, and Xavier Serra. "Freesound Datasets: A Platform for the Creation of Open Audio Datasets." International Society for Music Information Retrieval Conference (ISMIR), pp. 486–493. Suzhou, China, 2017.
[2] Ilya Kavalerov, Scott Wisdom, Hakan Erdogan, Brian Patton, Kevin Wilson, Jonathan Le Roux, and John R. Hershey. "Universal Sound Separation." IEEE Workshop on Applications of Signal Processing to Audio and Acoustics (WASPAA), pp. 175-179. New Paltz, NY, USA, 2019.
[3] Efthymios Tzinis, Scott Wisdom, John R. Hershey, Aren Jansen, and Daniel P. W. Ellis. "Improving Universal Sound Separation Using Sound Classification." IEEE International Conference on Acoustics Speech and Signal Processing (ICASSP), 2020.

Semantic Reactor: A tool for experimenting with NLU models

Companies are using natural language understanding (NLU) to create digital personal assistants, customer service bots, and semantic search engines for reviews, forums and the news.

However, the perception that using NLU and machine learning is costly and time consuming prevents a lot of potential users from exploring its benefits.

To dispel some of the intimidation of using NLU, and to demonstrate how it can be easily used with pre-trained, generic models, we have released a tool, the Semantic Reactor, and open-sourced example code, The Mystery of the Three Bots.

The Semantic Reactor

The Semantic Reactor is a Google Sheets Add-On that allows the user to sort lines of text in a sheet using a variety of machine-learning models. It is released as a whitelisted experiment, so if you would like to check it out, fill out this application at the Google Cloud AI Workshop. Once approved, you’ll be emailed instructions on how to install it.

The tool offers ranking methods that determine how the list will be sorted. With the semantic similarity method, the lines more similar in meaning to the input will be ranked higher.



With the input-response method, the lines that are the most appropriate conversational responses are ranked higher.

Why use the Semantic Reactor?

There are a lot of interesting things you can do with the Semantic Reactor, but let’s look at the following two:
  • Writing dialogue for a bot that exists within a well-defined environment and has a clear purpose (like a customer service bot) using semantic similarity.
  • Searching within large collections of text, like from a message board. For that, we will use input-response.

Writing Dialogue for a Bot Using Semantic Similarity

For the sake of an example, let’s say you are writing dialogue for a bot that answers questions about a product, in this case, cookies.

If you’ve been running a cookie hotline for a while, you probably can list the most common cookie questions. With that data, you can create your cookie bot. Start by opening a Google Sheet and writing the common questions and answers (questions in the A column, answers in the B).

Here is the start of what that Sheet might look like. Make a copy of the Sheet, which will allow you to use the Semantic Reactor Add-on. Use the tool to experiment with new QA pairs and how each model reacts to them.

Here are a few queries to try, using the semantic similarity rank method:

Query: What are cookie ingredients?
Returns: What are cookies made of?

Query: Are cookies biscuits?
Returns: Are cookies also called biscuits?

Query: What should I serve with cookies?
Returns: What drinks go well with cookies?



Of course, that small list of responses won’t cover many of the questions people will ask your cookie bot. What the Reactor allows you to do is quickly add new QA pairs as you learn about what your users want to ask.

For example, maybe people are asking a lot about cookie calories.

You’d write the new question in column A, and the new answer in column B, and then test a few different phrasings with the Reactor. You might need to tweak the target response a few times to make sure it matches a wide variety of phrasings. You should also experiment with the three different models to see which one performs the best.

For instance, let’s say the new target question you want the model to match to is: “How many calories does a typical cookie have?”

That question might be phrased by users as:
  • Are cookies caloric?
  • A lot of calories in a cookie?
  • Will cookies wreck my diet?
  • Are cookies fattening?


The more you test with live users, the more you’ll find that they phrase their questions in ways you don’t expect. As with all things based on machine learning, constantly refreshing data, testing and improvement is all part of the process.

Searching Through Text Using Input-Response

Sometimes you can’t anticipate what users are going to ask, and sometimes you might be dealing with a lot of potential responses, maybe thousands. In cases like that, you should use the input-response ranking method. That means the model will examine the list of potential responses and then rank each one according to what it thinks is the most likely response.

Here is a Sheet containing a list of simple conversational responses. Using the input-response ranking method, try a few generic conversational openers like “Hello” or “How’s it going?”

Note that in input-response mode, the model is predicting the most likely conversational response to an input and not the most semantically similar response.

Note that “Hello,” in input-response mode, returns “Nice to meet you.” In semantic similarity mode, “Hello” returns what the model thinks is semantically closest to “Hello,” which is “What’s up?”

Now try your own! Add potential responses. Switch between the models and ranking methods to see how it changes the results (be sure to hit the “reload” button every time you add new responses).

Example Code

One of the models available on TensorFlow Hub is the Universal Sentence Encoder Lite. It’s only 1.6MB and is suitable for use within websites and on-device applications.

An open sourced sample game that uses the USE Lite is Mystery of the Three Bots on Github. It’s a simple demonstration that shows how you can use a small semantic ML model to drive conversations with game characters. The corpora the game uses were created and tested using the Semantic Reactor.

You can play a running version of the game here. You can experiment with the corpora of two of the characters, the Maid and the Butler, contained within this Sheet. Be sure to make a copy of the Sheet so you can edit and add new QA pairs.

Where To Get The Models Used Within The Semantic Reactor

All of the models used in the Semantic Reactor are published and available online.
  • Local – Minified TensorFlow.js version of the Universal Sentence Encoder.
  • Basic Online – Basic version of the Universal Sentence Encoder.
  • Multilingual Online – Universal Sentence Encoder trained on question/ answer pairs in 16 languages.

Final Thoughts

These language models are far from perfect. They use their training to give a best estimate on what to return based on the list of responses you gave it. Machine learning is about calculation, prediction, and training. Models can be improved over time with more data and tuning, and in turn, be made more accurate.

Also, because conversational models are trained on dialogue between people, and because people are biased, the models will display biases that exist in the data that they were trained on, sometimes in ways you can’t predict. For more on model bias, and more detail about how these models were trained, see the Semantic Experiences for Developers page.

By Ben Pietrzak, Steve Pucci, Aaron Cohen — Google AI