CameraX: An Introduction
Android started out with android. This was a simple set of APIs which enabled developers to quickly implement a camera feature in their app. But having been added back in Android SDK 1, jesús hernán zambrano ruiz psychologist w ith started to get outdated. The market changed and users began to demand a lot more from their phone camera.
Android introduced the Camera2 APIs. These gave manufacturers and developers the ability to add more complex camera features. Although a comprehensive API, many developers found it too complicated to implement for a simple use case. CameraX introduces the idea of use-cases. These use-cases wrap up a whole set of functionality into a simple API.
CameraX is launching with 3 use-cases. Preview, which is getting an image on a display. Image analysis, which gives access to a stream of images for use in your algorithms, such as to pass into MLKit.
Image capture, to save high-quality images. These 3 use-cases will cover the vast majority of developers needs. They can be combined together or used individually. Not only does CameraX provide use-cases, but it also takes away all the device-specific nuances. Android is investing in an automated test lab in order to ensure that all the CameraX APIs behave the same.
Regardless of what device you are on. To cater for these weird and wonderful camera features, they have created an extensions API. With this API you can query for the availability of a particular extension and enable it. First, you need to add the required dependencies. Ensure that you add both of these, even though the second one might sound optional in the developer documentation.
Notice that we called startCamera within a post on the TextureView. This is to ensure that the TextureView has been inflated. We use the PreviewConfig. Builder and the ImageCaptureConfig. Builder to set up our use-cases.CameraX is a Jetpack support library, built to help you make camera app development easier. It provides a consistent and easy-to-use API surface that works across most Android devices, with backward-compatibility to Android 5.
While it leverages the capabilities of camera2, it uses a simpler, use case-based approach that is lifecycle-aware. It also resolves device compatibility issues for you so that you don't have to include device-specific code in your code base. These features reduce the amount of code you need to write when adding camera capabilities to your app. Lastly, CameraX enables developers to leverage the same camera experiences and features that preinstalled camera apps provide, with as little as two lines of code.
CameraX Extensions are optional add-ons that enable you to add effects on supported devices. The core CameraX libraries are in beta stage. Beta releases are functionally stable and have a feature-complete API surface. They are ready for production use but may contain bugs. For more information on the status of each library, see the CameraX library status page.
Figure 1. CameraX targets Android 5. CameraX introduces use caseswhich allow you to focus on the task you need to get done instead of spending time managing device-specific nuances. There are several basic use cases: Preview : get an image on the display Image analysis : access a buffer seamlessly for use in your algorithms, such as to pass into MLKit Image capture : save high-quality images. These use cases work across all devices running Android 5. Figure 2. Automated CameraX test lab ensures a consistent API experience across many device types and manufacturers.
Managing consistent camera behavior across apps is hard. There is a lot to account for, including aspect ratio, orientation, rotation, preview size, and high-resolution image size. With CameraX, these basic behaviors just work. These tests are run on an ongoing basis to identify and fix a wide range of issues. Figure 3. CameraX enables new in-app experiences like portrait effects. CameraX has an optional add-on, called Extensionswhich allow you to access the same features and capabilities as those in the native camera app that ships with the device, with just two lines of code.
These capabilities are available on supported devices. To see how CameraX has simplified development for Monzo, see their case study.
Android CameraX: Preview, Analyze, Capture.
Content and code samples on this page are subject to the licenses described in the Content License. App Basics. Build your first app. App resources.
Resource types. App manifest file.The camera is central to the mobile device experience, with many popular apps using it in some way.
You need to account for variations due to different versions of Android running on different devices, and edge cases tied to those differences. CameraX is a new Jetpack library that simplifies the process of integrating the device camera into your Android app. The app will show the a camera preview in the bottom half of the screen and the most recent photo in the top half.
CameraX is a part of the growing Jetpack support library.
It has backward compatibility down to Android API It replaces Camera2 while supporting all the same devices — without the need for device-specific code! The library provides abstractions for some helpful use caseswhich are used to complete a specific task. The primary three are:. Also of note, CameraX brings life to vendor extensionswhich are features that display special effects on some devices.
CameraX lets you add extensions to your app with just a few lines of code. Currently, the supported effects are:. Click on the Download Materials button at the top or bottom of the page to access the begin and end projects for this tutorial. Next, open Android Studio. From the welcome screen, select Open an existing Android Studio project. Either way, select the top-level project folder for the begin project.#AskAndroid at Android Dev Summit 2019 - CameraX
Open the main package, com. Also, notice that the app uses two CameraX dependencies, which you can see in the build. Your device will ask for permission to access the camera. Notice that you already have a Save Image switch and a drop-down menu on the toolbar.
To create a camera preview, you need to have a view that can display it. Change the view type to TextureView and delete the line that sets the background to black.
TextureView allows you to stream media content, like videos, which is exactly what you need to display a camera preview. You do this by:. Add this below updateTransform :.
Notice how this method is almost identical to the createPreviewUseCase. The only differences are:.C ameraX is a Jetpack support library which is in Alpha at present.
CameraX library is build to simplify the usage of camera features in app development. CameraX provides an in-depth analysis of what camera is pointed at through Image Analysis and also provides a way to use built-in device camera features like HDR, portrait mode and so on through extensions.
There is a concept called use-case in CameraX which enhances developer interaction by using specific use-case instead of focusing on managing all the device-specific nuances. There are three use-cases to get-started, they are.
That being said CameraX is in Alpha, please note that it is not good to use in your production app yet. CameraX library is backward compatibility to Android L, that being said add the following lines to your build. The preview use-case offers a TextureView where the camera output is streamed. The image analysis use-case provides a virtually accessible image to operate image processing, apply machine learning and many more image analyzing techniques.
That being said, with ImageAnalysis. Analyzer an ImageProxy is obtained through which we can get the image and use that virtual image in ML kit as shown below. Through image capture, you can save high-resolution images with very minimal code have a look. Here is the use-case configuration to take a photo. For a device to support vendor extensions, all of the following must be true:.
To apply vendor extensions to CameraX use cases, create an Extender object, which allows you to configure the Builder with the settings for that effect or function. Query the extension for availability, because if an extension is unavailable the enableExtension call will not do anything. To disable vendor extensions we have to create the new image capture use case instance.
CameraX is still in Alpha iterations there might be changes in the code in future releases so I suggest you do not use CameraX in your production apps yet. Sign in. Submit Archive About Events droidcon. CameraX — sneak peek into an upcoming Jetpack support library. Exploring the new CameraX library in Android. Siva Ganesh Kantamani Follow. CameraX overview Android Developers CameraX is a Jetpack support library, built to help you make camera app development easier.
It provides a consistent….
The library…. ProAndroidDev Follow. Write the first response. More From Medium. More from ProAndroidDev. Somesh Kumar in ProAndroidDev. Denys Soroka in ProAndroidDev. Andrew Lord in ProAndroidDev. Discover Medium. Make Medium yours. Become a member. About Help Legal.We have already discussed the basics of CameraX here. CameraX which comes with Android Jetpack is all about use cases. Basically, a camera can be built using three core use cases — Preview, Analyse, Capture. OpenCV is a computer vision libraries which contains more than algorithms related to image processing.
Thankfully, a lot of high-level stuff in OpenCV can be done in Java. This method is a part of OpenCV android. Mat class is basically used to hold the image. It consists of a matrix header and a pointer to the matrix which contains pixels values. In our image analysis, we convert the mat color space from one type to another use ImgProc. Having converted the mat to a different color space, we then convert it a bitmap and show it on the screen in an ImageView.
By default, the image is of RGB type. So we were able to analyze, view the captured frame and optionally save it in our internal storage directory. That brings an end to this tutorial. You can download the project from the link below or view the full source code in our Github repository. Can you explain a bit? Thank you. I want to convert my capture image into Canny Edge form But application is getting crashed.
I want to create face recogition attendence system app. Hİ, thank you for this article. Really appreciate your blog post, really helpful and insightful on how to use the CameraX api given that it is in its infancy stage and is a much improved cleaner version over the messy Camera2 api plagued with boiler plate code that makes reading and writing code a painful process for a beginner like me. Would like to seek your help on this, or by any chance if you have any contacts w google developers, could you kindly help to raise this issue to them, as I belief this feature would be widely used and would benefit others too.
Sorry for the rambling, just appreciate all that you have done, really helpful. Your email address will not be published. I would love to connect with you personally. Did you know? Android Camerax Opencv Project Structure. Android Camerax Opencv Output New. Github Project Link.
Prev Android Motion Layout. Shoot him queries. Follow Author. Comments Yash says:. April 15, at am.Main goal of the library is to help developers to make camera app development easier by providing consistent and easy to use API. You can read more about CameraX here. You can read more about Firebase ML Kit here. I have given my package name as com. Add Firebase to your Android project.
Currently following use cases are available:. Preview : allows you to access a stream of camera input which you can use to display the camera stream in TextureView. Image analysis : allows you to analyze each frame of camera input.
As it is mentioned above, to show camera stream on the screen, we need to use Preview use case. When we create instance of Preview use case, we need to pass PreviewConfig as constructor parameter.
The preview use case provides a SurfaceTexture for display. To show camera stream in our textureViewwe need to add listener to preview instance using setOnPreviewOutputUpdateListener method:.
As CameraX observes a lifecycle to manage camera resources, we need to bind our use case using CameraX. Here is how startCamera function looks like in MainActivity :. Now we need to detect QR codes from camera input using ImageAnalysis use case. Analyzer interface. Analyzer has function called analyze ImageProxy image, int rotationDegreesand this is where we will add QR code detection related code. Get instance of FirebaseVisionBarcodeDetector :.
Create FirebaseVisionImage from frame:. In this step we also need to convert ImageAnalysis. Here is how QrCodeAnalyzer class should look like when you follow steps mentioned above.CameraX is an Android Jetpack library that was built with the intent to make camera development easier, which until now has been quite painful.
In contrast with the fine grained control camera2's API offered, CameraX which uses the Camera2 API under the hood aims to strike a balance between abstracting away the difficult bits of managing the camera while allowing flexibility and customization. CameraX is a use case based API, it has abstracted 3 main handles which you can use to interact with the camera: Preview, Image analysis and Image capture.
Choosing which use case s to use depends on what you intend to use the camera for. The Preview use case is instantiated using a configuration defined in PreviewConfig. The rotation can also be configured, which could should? And lastly you can select to use the back or front facing camera. The preview provides a listener which is called once it -the preview- is active.
It receives an output containing a surface which can be attached to a TextureView 's SurfaceTexture in your layout, this will allow to display the preview stream. When the device is in landscape mode for example, the preview should be rotated. This can be done by applying a transformation on the TextureView displaying the camera feed preview.
Similar to the preview use case, the image analysis use case is instantiated using a configuration defined in ImageAnalysisConfig. The ImageAnalysis instance takes in an analyzer which specifies what to do with the incoming images from the preview, it receives ImageProxy objects, which contain information that can be processed for image analysis through its planes attribute which contain pixel data about the image.
The analysis should be handled fast enough so as not to stall the image acquisition pipeline, or the image data should be copied elsewhere for longer processing. In addition to the configuration parameters used in the preview use case resolution, aspect ratio and rotationa reader mode can be set for the image analysis use case, this specifies how the images passed in for analysis are selected.
The former takes in the latest image from the image acquisition pipeline while disregarding any other older images, the latter takes in the next image in the pipeline. Lastly, the depth queue is a parameter that specifies the number of images available in the pipeline for the analyzer. The end goal for most camera usages is to take a photo, this is the role of the image capture use case.
It follows the same pattern as the other 2 use cases. This listener contains 2 callbacks for successful and failed image capture operations.
This step takes the burden off the developer to setup, start and shutdown the camera resources in the right order in the correct lifecycle callbacks. With the use cases bound to a lifecycle, once the latter is active, the preview comes up, the image analyzer begins to receive images at the camera frame-rate and the image capture becomes available. In the examples above for building and setting up the use cases, I used variables such as aspect ratio, resolution and rotation.
For instance, using a TextureViewyou could write the following to set these parameters. You can achieve this by first adding the permission in your manifest. Then request the camera permission at runtime from your activity or fragment. Not having to worry about how to handle the camera while getting the opportunity to focus more on what to build with and around it is great.
In addition, assuming the automated test lab continues to test CameraX on a multitude of devices, the need for manual testing will become less of a necessity.
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