Posted by Erica Hanson, Global Program Manager, Google Developer Student Clubs
(Irene (left) and her DSC team from the Polytechnic University of Cartagena (photo prior to COVID-19)
Irene Ruiz Pozo is a former Google Developer Student Club (DSC) Lead at the Polytechnic University of Cartagena in Murcia, Spain. As one of the founding members, Irene has seen the club grow from just a few student developers at her university to hosting multiple learning events across Spain. Recently, we spoke with Irene to understand more about the unique ways in which her team helped local university students learn more about Google technologies.
Irene mentioned two fascinating projects that she had the chance to work on through her DSC at the Polytechnic University of Cartagena. The first was a learning lab that helped students understand how to use 360º cameras and 3D scanners for machine learning.
(A DSC member giving a demo of a 360º camera to students at the National Museum of Underwater Archeology in Cartagena)
The second was a partnership with the National Museum of Underwater Archeology, where Irene and her team created an augmented reality game that let students explore a digital rendition of the museum’s exhibitions.
(An image from the augmented reality game created for the National Museum of Underwater Archeology)
In the above AR experience created by Irene’s team, users can create their own character and move throughout the museum and explore different virtual renditions of exhibits in a video game-like setting.
One particularly memorable experience for Irene and her DSC was participating in Google’s annual programming competition, Hash Code. As Irene explained, the event allowed developers to share their skills and connect in small teams of two to four programmers. They would then come together to tackle engineering problems like how to best design the layout of a Google data center, create the perfect video streaming experience on YouTube, or establish the best practices for compiling code at Google scale.
(Students working on the Hash Code competition (photo taken prior to COVID-19)
To Irene, the experience felt like a live look at being a software engineer at Google. The event taught her and her DSC team that while programming skills are important, communication and collaboration skills are what really help solve problems. For Irene, the experience truly bridged the gap between theory and practice.
(Irene’s team working with other student developers (photo taken before COVID-19)
After the event, Irene felt that if a true mentorship network was established among other DSCs in Europe, students would feel more comfortable partnering with one another to talk about common problems they faced. Inspired, she began to build out her mentorship program which included a podcast where student developers could collaborate on projects together.
The podcast, which just released its second episode, also highlights upcoming opportunities for students. In the most recent episode, Irene and friends dive into how to apply for Google Summer of Code Scholarships and talk about other upcoming open source project opportunities. Organizing these types of learning experiences for the community was one of the most fulfilling parts of working as a DSC Lead, according to Irene. She explained that the podcast has been an exciting space that allows her and other students to get more experience presenting ideas to an audience. Through this podcast, Irene has already seen many new DSC members eager to join the conversation and collaborate on new ideas.
As Irene now looks out on her future, she is excited for all the learning and career development that awaits her from the entire Google Developer community. Having graduated from university, Irene is now a Google Developer Groups (GDG) Lead - a program similar to DSC, but created for the professional developer community. In this role, she is excited to learn new skills and make professional connections that will help her start her career.
Are you also a student with a passion for code? Then join a local Google Developer Student Club near you, here.
Since we launched Coral back in March 2019, we’ve added a number of new product form factors to accommodate the many ways users are adding on-device ML to their products. We've also streamlined the ML workflow and added capabilities like model pipelining with multiple Edge TPUs for an easier and more robust developer experience. And from this, we’ve helped enable amazing use cases from smart water meters that prevent water loss with Olea Edge, to systems for improving harvest yield with Farmwave, to noise cancellation in meetings in Google’s own Series One meeting kits.
This week, we’ll begin shipping the Coral Accelerator Module, a multi-chip module that combines the Edge TPU and it’s power circuitry into a solderable package. The module exposes PCIe and USB2 interfaces, which make it even easier to integrate Coral into custom designs. Several companies are already taking advantage of the compact size and capabilities with their new products coming to market. Read more about how Gumstix, STD, Siana Systems and IEI are using our module.
And in December, we’ll begin shipping the Dev Board Mini, a smaller, more power-efficient, and value-oriented board that brings forward a more traditional, flattened single-board computer design. The Dev Board Mini pairs a Mediatek 8167 SoC with the Coral Accelerator Module over USB 2 and is a great way to evaluate the module as the center of a project or deployment.
You can see the new Dev Board Mini and Accelerator Module in action in the latest episode of Level Up, where Markku Lepisto controls his studio lights with speech commands.
To get updates on when the board will be available for purchase and other Coral news, sign up for our newsletter.
We recently announced a new version of the Coral ML APIs and tools. This release brings the C++ API into parity with Python and makes it more modular, reusable and performant. At the same time it eliminates unnecessary abstractions and surfaces replacing them with native TensorFlow Lite APIs. This release also graduates the Model Pipelining API out of beta and introduces a new model partitioner that automatically partitions models based on profiling and up to 10x better performance.
We’ve added a pre-trained version of MobileDet — a state-of-the-art object detection model for mobile systems — into our models portfolio. We’re migrating our model-development workflow to TensorFlow 2, and we’re including a handful of updated or new models based on the TF2 Keras framework. For details, check out the full announcement on the TensorFlow blog.
We’re also excited to see great developer tools coming from our ecosystem partners. For example, PerceptiLabs offers a visual API for building TensorFlow models and recently published a new demo which trains a machine learning model to identify sign language optimized for the edge with Coral.
The MRQ design from SigFox enables prototyping at the edge for low bandwidth IoT solutions with Coral
And SigFox released a radio transceiver board that stacks on either the Coral Dev Board or Dev Board Mini. This allows small data payloads to be transmitted across low power, long range radio networks for use cases like smart cities, fleet management, asset tracking, agriculture and energy. The PCB design will be offered as a free download on SigFox’s website. Google Cloud Solutions Architect Markku Lepisto will present the new design today, in the opening keynote at SigFox Connect.
The tool, from Farmwave, includes custom-developed ML models, a harvester-mounted box with cameras, an in-cab display, and on- device AI acceleration from Coral.
Just in time for harvest we wanted to share a story about how Farmwave is using Coral to improve the efficiency of farm equipment and reduce food waste. Traditional yield loss analysis involves hand-counting grains of corn left on the ground mid harvest. It’s a time and labor intensive task, and not feasible for farmers who measure the value of their half-million-dollar combines in minutes spent running them.
By leveraging Coral’s on-device AI capabilities, Farmwave was able to build a system that automates the count while the machine is running. Thus allowing farmers to make real-time adjustments to harvesting machines in response to conditions in the field, which can make a big difference in yield.
Kura Sushi designed their intelligent QA system using a Raspberry Pi paired with the Coral USB Accelerator
Kura Revolving Sushi Bar in Japan has always been committed to the highest standards of health and safety for its customers. Known for their tech forward approach, Kura has dabbled in sushi making robots, an automated prize machine called Bikkura-pon, and a patented dome-shaped dish cover, aptly dubbed Mr. Fresh. But most recently, Kura has used Coral to develop an AI powered system that not only facilitates efficiency for better customer experiences, but also enables better tracking to prevent foodborne illnesses.
While this year has presented the world with many obstacles, we’ve been impressed by the new ideas and innovations coming forward through technology. By providing the necessary tools and technology for edge AI, we strive to empower society to create affordable, adaptable, and intelligent systems.
We are excited to share all that Coral has to offer as we evolve our platform. For a list of worldwide distributors, system integrators and partners, visit the Coral partnerships page.
Please visit Coral.ai to discover more about our edge ML platform and share your feedback at coral-support@google.com. To receive future Coral updates directly in your inbox, sign up for our newsletter.
Posted by The Coral Team
Moving into the fall, the Coral platform continues to grow with the release of the M.2 Accelerator with Dual Edge TPU. Its first application is in Google’s Series One room kits where it helps to remove interruptions and makes the audio clearer for better video meetings. To help even more folks build products with Coral intelligence, we’re dropping the prices on several of our products. And for those folks that are looking to level up their at home video production, we’re sharing a demo of a pose based AI director to make multi-camera video easier to make.
Coral M.2 Accelerator with Dual Edge TPU
The newest addition to our product family brings two Edge TPU co-processors to systems in an M.2 E-key form factor. While the design requires a dual bus PCIe M.2 slot, it brings enhanced ML performance (8 TOPS) to tasks such as running two models in parallel or pipelining one large model across both Edge TPUs.
The ability to scale across multiple edge accelerators isn’t limited to only two Edge TPUs. As edge computing expands to local data centers, cell towers, and gateways, multi-Edge TPU configurations will be required to help process increasingly sophisticated ML models. Coral allows the use of a single toolchain to create models for one or more Edge TPUs that can address many different future configurations.
A great example of how the Coral M.2 Accelerator with Dual Edge TPU is being used is in the Series One meeting room kits for Google Meet.
The new Series One room kits for Google Meet run smarter with Coral intelligence
Google’s new Series One room kits use our Coral M.2 Accelerator with Dual Edge TPU to bring enhanced audio clarity to video meetings. TrueVoice®, a multi-channel noise cancellation technology, minimizes distractions to ensure every voice is heard with up to 44 channels of echo and noise cancellation, making distracting sounds like snacking or typing on a keyboard a concern of the past.
Enabling the clearest possible communication in challenging environments was the target for the Google Meet hardware team. The consideration of what makes a challenging environment was not limited to unusually noisy environments, such as lunchrooms doubling as conference rooms. Any conference room can present challenging acoustics that make it difficult for all participants to be heard.
The secret to clarity without expensive and cumbersome equipment is to use virtual audio channels and AI driven sound isolation. Read more about how Coral was used to enhance and future-proof the innovative design.
Expanding the AI edge
Earlier this year, we reduced the prices of our prototyping devices and sensors. We are excited to share further price drops on more of our products. Our System-on-Module is now available for $99.99, and our Mini PCIe Accelerator, M.2 Accelerator A+E Key, and M.2 Accelerator B+M key are now available at $24.99. We hope this lower price will make our edge AI more accessible to more creative minds around the world. Later, this month our SoM offering will also expand to include 2 and 4GB RAM options.
Multi-cam with AI
As we expand our platform and product family, we continue to keep new edge AI use cases in mind. We are continually inspired by our developer community’s experimentation and implementations. When recently faced with the challenges of multicam video production from home, Markku Lepistö, Solutions Architect at Google Cloud, created this real-time pose-based multicam tool he so aptly dubbed, AI Director.
We love seeing such unique implementations of on-device ML and invite you to share your own projects and feedback at coral-support@google.com.
For a list of worldwide distributors, system integrators and partners, visit the Coral partnerships page. Please visit Coral.ai to discover more about our edge ML platform.
Posted by Kenny Sulaimon, Product Manager, ML Kit; Chengji Yan and Areeba Abid, Software Engineers, ML Kit
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.
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
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.
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 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
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.
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.
Posted by the Coral Team
Summer has arrived along with a number of Coral updates. We're happy to announce a new partnership with balena that helps customers build, manage, and deploy IoT applications at scale on Coral devices. In addition, we've released a series of updates to expand platform compatibility, make development easier, and improve the ML capabilities of our devices.
First up, our Edge TPU runtime is now open-source and available on GitHub, including scripts and instructions for building the library for Linux and Windows. Customers running a platform that is not officially supported by Coral, including ARMv7 and RISC-V can now compile the Edge TPU runtime themselves and start experimenting. An open source runtime is easier to integrate into your customized build pipeline, enabling support for creating Yocto-based images as well as other distributions.
Coral customers can now also use the Mini PCIe and M.2 accelerators on the Microsoft Windows platform. New Windows drivers for these products complement the previously released Windows drivers for the USB accelerator and make it possible to start prototyping with the Coral USB Accelerator on Windows and then to move into production with our Mini PCIe and M.2 products.
We’ve also made a number of new updates to our ML tools:
sudo apt-get update && sudo apt-get install edgetpu
We are excited to share that the Balena fleet management platform now supports Coral products!
Companies running a fleet of ML-enabled devices on the edge need to keep their systems up-to-date with the latest security patches in order to protect data, model IP and hardware from being compromised. Additionally, ML applications benefit from being consistently retrained to recognize new use cases with maximum accuracy. Coral + balena together, bring simplicity and ease to the provisioning, deployment, updating, and monitoring of your ML project at the edge, moving early prototyping seamlessly towards production environments with many thousands of devices.
Read more about all the benefits of Coral devices combined with balena container technology or get started deploying container images to your Coral fleet with this demo project.
Mendel Linux (5.0 release Eagle) is now available for the Coral Dev Board and SoM and includes a more stable package repository that provides a smoother updating experience. It also brings compatibility improvements and a new version of the GPU driver.
Last but not least, we’ve recently released BodyPix, a Google person-segmentation model that was previously only available for TensorFlow.JS, as a Coral model. This enables real-time privacy preserving understanding of where people (and body parts) are on a camera frame. We first demoed this at CES 2020 and it was one of our most popular demos. Using BodyPix we can remove people from the frame, display only their outline, and aggregate over time to see heat maps of population flow.
Here are two possible applications of BodyPix: Body-part segmentation and anonymous population flow. Both are running on the Dev Board.
We’re excited to add BodyPix to the portfolio of projects the community is using to extend our models far beyond our demos—including tackling today’s biggest challenges. For example, Neuralet has taken our MobileNet V2 SSD Detection model and used it to implement Smart Social Distancing. Using the bounding box of person detection, they can compute a region for safe distancing and let a user know if social distance isn’t being maintained. The best part is this is done without any sort of facial recognition or tracking, with Coral we can accomplish this in real-time in a privacy preserving manner.
We can’t wait to see more projects that the community can make with BodyPix. Beyond anonymous population flow there’s endless possibilities with background and body part manipulation. Let us know what you come up with at our community channels, including GitHub and StackOverflow.
We are excited to share all that Coral has to offer as we continue to evolve our platform. For a list of worldwide distributors, system integrators and partners, including balena, visit the Coral partnerships page. Please visit Coral.ai to discover more about our edge ML platform and share your feedback at coral-support@google.com.
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
Day 1
Day 2
Day 3
Day 4
Day 5
Day 6
Day 7
Day 8
Day 9
Day 10
Day 11
Day 12
Day 13
Wrap up!
We hope you enjoy this list of the most common reference architectures. Please let us know your thoughts in the comments below!
Posted by Billy Rutledge, Director of the Coral team
Recently, we’ve seen communities respond to the challenges of the coronavirus pandemic by using technology in new ways to effect positive change. It’s increasingly important that our systems are able to adapt to new contexts, handle disruptions, and remain efficient.
At Coral, we believe intelligence at the edge is a key ingredient towards building a more resilient future. By making the latest machine learning tools easy-to-use and accessible, innovators can collaborate to create solutions that are most needed in their communities. Developers are already using Coral to build solutions that can understand and react in real-time, while maintaining privacy for everyone present.
As mandatory isolation measures begin to relax, compliance with safe social distancing protocol has become a topic of primary concern for experts across the globe. Businesses and individuals have been stepping up to find ways to use technology to help reduce the risk and spread. Many efforts are employing the benefits of edge AI—here are a few early stage examples that have inspired us.
In Belgium, engineers at Edgise recently used Coral to develop an occupancy monitor to aid businesses in managing capacity. With the privacy preserving properties of edge AI, businesses can anonymously count how many customers enter and exit a space, signaling when the area is too full.
A research group at the Sathyabama Institute of Science and Technology in India are using Coral to develop a wearable device to serve as a COVID-19 cough counter and health monitor, allowing medical professionals to better care for low risk patients in an outpatient capacity. Coral's Edge TPU enables biometric data to be processed efficiently, without draining the limited power resources available in wearable devices.
All across the US, hospitals are seeking solutions to ensure adherence to hygiene policy amongst hospital staff. In one example, a device incorporates the compact, affordable and offline benefits of the Coral modules to aid in handwashing practices at numerous stations throughout a facility.
And around the world, members of the PyImageSearch community are exploring how to train a COVID-19: Face Mask Detector model using TensorFlow that can be used to identify whether people are wearing a mask. Open source frameworks can empower anyone to develop solutions, and with Coral components we can help bring those benefits to everyone.
In an effort to rally greater community involvement, Coral has joined The United Nations Development Programme and Hackster.io, as a sponsor of the COVID-19 Detect and Protect Challenge. The initiative calls on developers to build affordable and reproducible solutions that support response efforts in developing countries. All ideas are welcome—whether they use ML or not—and we encourage you to participate.
To make edge ML capabilities even easier to integrate, we’re also announcing a price reduction for the Coral products widely used for experimentation and prototyping. Our Dev Board will now be offered at $129.99, the USB Accelerator at $59.99, the Camera Module at $19.99, and the Enviro Board at $14.99. Additionally, we are introducing the USB Accelerator into 10 new markets: Ghana, Thailand, Singapore, Oman, Philippines, Indonesia, Kenya, Malaysia, Israel, and Vietnam. For more details, visit Coral.ai/products.
We’re excited to see the solutions developers will bring forward with Coral. And as always, please keep sending us feedback at coral-support@google.com.
Posted by Zhicheng Wang and Genzhi Ye, MediaPipe team
In many computer vision applications, a crucial building block is to establish reliable correspondences between different views of an object or scene, forming the foundation for approaches like template matching, image retrieval and structure from motion. Correspondences are usually computed by extracting distinctive view-invariant features such as SIFT or ORB from images. The ability to reliably establish such correspondences enables applications like image stitching to create panoramas or template matching for object recognition in videos (see Figure 1).
Today, we are announcing KNIFT (Keypoint Neural Invariant Feature Transform), a general purpose local feature descriptor similar to SIFT or ORB. Likewise, KNIFT is also a compact vector representation of local image patches that is invariant to uniform scaling, orientation, and illumination changes. However unlike SIFT or ORB, which were engineered with heuristics, KNIFT is an embedding learned directly from a large number of corresponding local patches extracted from nearby video frames. This data driven approach implicitly encodes complex, real-world spatial transformations and lighting changes in the embedding. As a result, the KNIFT feature descriptor appears to be more robust, not only to affine distortions, but to some degree of perspective distortions as well. We are releasing an implementation of KNIFT in MediaPipe and a KNIFT-based template matching demo in the next section to get you started.
Please note that the information, uses, and applications expressed in the below post are solely those of our guest author, Alfred Camera.
In this article, we’d like to give you a short overview of Alfred Camera and our experience of using MediaPipe to transform our moving object feature, and how MediaPipe has helped to get things easier to achieve our goals.
Fig.1 Alfred Camera Logo
Alfred Camera is a smart home app for both Android and iOS devices, with over 15 million downloads worldwide. By downloading the app, users are able to turn their spare phones into security cameras and monitors directly, which allows them to watch their homes, shops, pets anytime. The mission of Alfred Camera is to provide affordable home security so that everyone can find peace of mind in this busy world.
The Alfred Camera team is composed of professionals in various fields, including an engineering team with several machine learning and computer vision experts. Our aim is to integrate AI technology into devices that are accessible to everyone.
Alfred Camera currently has a feature called Moving Object Detection, which continuously uses the device’s camera to monitor a target scene. Once it identifies a moving object in the area, the app will begin recording the video and send notifications to the device owner. The machine learning models for detection are hand-crafted and trained by our team using TensorFlow, and run on TensorFlow Lite with good performance even on mid-tier devices. This is important because the app is leveraging old phones and we'd like the feature to reach as many users as possible.
We had started building our AI features at Alfred Camera since 2017. In order to have a solid foundation to support our AI feature requirements for the coming years, we decided to rebuild our real-time video analysis pipeline. At the beginning of the project, the goals were to create a new pipeline which should be 1) modular enough so we could swap core algorithms easily with minimal changes in other parts of the pipeline, 2) having GPU acceleration designed in place, 3) cross-platform as much as possible so there’s no need to create/maintain separate implementations for different platforms. Based on the goals, we had surveyed several open source projects that had the potential but we ended up using none of them as they either fell short on the features or were not providing the readiness/stabilities that we were looking for.
We started a small team to prototype on those goals first for the Android platform. What came later were some tough challenges way above what we originally anticipated. We ran into several major design changes as some key design basics were overlooked. We needed to implement some utilities to do things that sounded trivial but required significant effort to make it right and fast. Dealing with asynchronous processing also led us into a bunch of timing issues, which took the team quite some effort to address. Not to mention debugging on real devices was extremely inefficient and painful.
Things didn't just stop here. Our product is also on iOS and we had to tackle these challenges once again. Moreover, discrepancies in the behavior between the platform-specific implementations introduced additional issues that we needed to resolve.
Even though we finally managed to get the implementations to the confidence level we wanted, that was not a very pleasant experience and we have never stopped thinking if there is a better option.
Google open sourced MediaPipe project in June 2019 and it immediately caught our attention. We were surprised by how it is perfectly aligned with the previous goals we set, and has functionalities that could not have been developed with the amount of engineering resources we had as a small company.
We immediately decided to start an evaluation project by building a new product feature directly using MediaPipe to see if it could live up to all the promises.
To start the evaluation, we decided to migrate our existing moving object feature to see what exactly MediaPipe can do.
Our current Moving Object Detection pipeline consists of the following main components:
Our current implementation has taken GPU into consideration as much as we can. A series of shaders are created to perform the tasks above and the pipeline is designed to avoid moving pixels between CPU/GPU frequently to eliminate the potential performance hits.
The pipeline involves multiple ML models that are conditionally executed, mixed CPU/GPU processing, etc. All the challenges here make it a perfect showcase for how MediaPipe could help develop a complicated pipeline.
MediaPipe provides a lot of code samples for any developer to bootstrap with. We took the Object Detection on Android sample that comes with the project to start with because of the similarity with the back-end part of our pipeline. It did take us sometimes to fully understand the design concepts of MediaPipe and all the tools associated. But with the complete documentation and the great responsiveness from the MediaPipe team, we got up to speed soon to do most of the things we wanted.
That being said, there were a few challenges we needed to overcome on the road to full migration. Our original pipeline of Moving Object Detection takes the input frame asynchronously, but MediaPipe has timestamp bound limitations such that we cannot just show the result in an allochronic way. Meanwhile, we need to gather data through JNI in a specific data format. We came up with a workaround that conquered all the issues under the circumstances, which will be mentioned later.
After wrapping our models and the processing logics into calculators and wired them up, we have successfully transformed our existing implementation and created our first MediaPipe Moving Object Detection pipeline like the figure below, running on Android devices:
Fig.2 Moving Object Detection Graph
We do not block the video frame in the main calculation loop, and set the detection result as an input stream to show the annotation on the screen. The whole graph is designed as a multi-functioned process, the left chunk is the debug annotation and video frame output module, and the rest of the calculation occurs in the rest of the graph, e.g., low light detection, motion triggered detection, cropping of the area of interest and the detection process. In this way, the graph process will naturally separate into real-time display and asynchronous calculation.
As a result, we are able to complete a full processing for detection in under 40ms on a device with Snapdragon 660 chipset. MediaPipe’s tight integration with TensorFlow Lite provides us the flexibility to get even more performance gain by leveraging whatever acceleration techniques available (GPU or DSP) on the device.
The following figure shows the current implementation working in action:
Fig.3 Moving Object Detection running in Alfred Camera
After getting things to run on Android, Desktop GPU (OpenGL-ES) emulation was our next target to evaluate. We are already using OpenGL-ES shaders for some computer vision operations in our pipeline. Having the capability to develop the algorithm on desktop, seeing it work in action before deployment onto mobile platforms is a huge benefit to us. The feature was not ready at the time when the project was first released, but MediaPipe team had soon added Desktop GPU emulation support for Linux in follow-up releases to make this possible. We have used the capability to detect and fix some issues in the graphs we created even before we put things on the mobile devices. Although it currently only works on Linux, it is still a big leap forward for us.
Testing the algorithms and making sure they behave as expected is also a challenge for a camera application. MediaPipe helps us simplify this by using pre-recorded MP4 files as input so we could verify the behavior simply by replaying the files. There is also built-in profiling support that makes it easy for us to locate potential performance bottlenecks.
The result of the evaluation and the feedback from our engineering team were very positive and promising:
With just a few weeks working with MediaPipe, it has shown strong capabilities to fundamentally transform how we develop our products. Without MediaPipe we could have spent months creating the same features without the same level of performance.
Alfred Camera is designed to bring home security with AI to everyone, and MediaPipe has significantly made achieving that goal easier for our team. From Moving Object Detection to future AI-powered features, we are focusing on transforming a basic security camera use case into a smart housekeeper that can help provide even more context that our users care about. With the support of MediaPipe, we have been able to accelerate our development process and bring the features to the market at an unprecedented speed. Our team is really excited about how MediaPipe could help us progress and discover new possibilities, and is looking forward to the enhancements that are yet to come to the project.
