LibGDX Android Studio: Download and set up a new LibGDX Project

LibGDX android Setup

Hey fellow developers!

Welcome to the beginning of LibGDX for Android tutorials. In this tutorial, you will learn how to download, setup and create a new LibGDX project in Android Studio.

At the end of this tutorial, you will:

  1. Download LibGDX
  2. Setup LibGDX
  3. Create a new LibGDX project in Android Studio

So lets get Started!


Download LibGDX

First of all, lets download LibGDX. (I am assuming that you already have Android Studio.)

  1. Go to official LibGDX website.
  2. Go to Download
  3. Download (Duh!)
  4. And open the folder

This process is given here

 LibGDX Android Studio - Download

Now, we will setup LibGDX for our project.


Setup LibGDX

Now, we will setup the LibGDX project using the downloaded gdx-setup.java file.

  1. First of all, fill in the basic project information
    1. Run gdx-setup.java
    2. Provide your Project name.
    3. Provide package information according to your settings
    4. Game Class is the java class file name that you will eventually be working with.
    5. Destination is where you will work on your project.
    6. Android SDK is where your Android SDK is installed. Give its path.
  2. Sub-Projects is where you provide the platforms that you wish to support.
    1. Chose Android
      (Only because this is an android based tutorial. But you are not limited to that.)
  3. Extensions is where you tell the setup what extensions to load.
    1. For simplicity, just chose Box2d
      (you can learn more later)
  4. Press Generate
    1. Wait until the download completes.

Here is the screen shot of my completed setup.

This entire process is given below.

 LibGDX Android Studio - Setup

Now, we will open this project in Android Studio


Open in Android Studio

Follow these steps to load the LibGDX project in Android Studio

  1. Open Android Studio
  2. Click Import Project
    • Here is how
  3. Give path to the LibGDX download location (which you provided in setup) and press OK
    • Here is how
  4. Wait till the project is loaded in Android Studio

This entire process is given below:

LibGDX Android Studio - Load project in Android Studio

This is it. You have just loaded LibGDX in Android Studio. Now lets run it in Android Virtual Device 😀


Run LibGDX in Android Virtual Device

Follow these steps to run your new LibGDX project in AVD

  1. Launch your Android Virtual Device (AVD)
  2. Press the Run button in Android Studio
  3. Now, the app will run on your AVD. Done!

This process is given below:

LibGDX Android Studio -Launch app in AVD

This is it. You have just created and run a new LibGDX project in Android Studio.

Lets draw some shapes in the next tutorial.

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Creating a new OpenCV project in Android Studio

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In this tutorial, we will create a new OpenCV project in Android Studio. Since you have everything downloaded already, we are ready to move on. By the end of this tutorial, you will have a new project set up, which you can use to build your projects upon. So lets do some CV!

Note: This tutorial has been tested on Android Studio 1.5 and 2.0

In short, the steps are, (2) Create simple project. (3) Import OpenCV SDK as a Module in Android Studio. (4) Set OpenCV Version. in Project (5) Fix Library association in project. (6) Done! Now actual OpenCV code can be written in future. The longer and detailed guided tutorial is given below.

  1. I beg you to open Android studio.
  2. Create a new project
    • I named it “OpenCV_Test”. (It could be different in the following GIF)
    • Minimum SDK is “API 19: Android 4.4 (KitKat).
    • Default Activity is “Basic Activity” (easily changeable later on)
    • Activity name is “MainActivity” (i.e. default settings)
    • I have shown the entire process in this GIF.
      Android-Studio-Create-New-Project
    • After pressing Finish, Gradle will perform some processes and eventually, you will be presented with your Android project.
    • Now, we can start importing OpenCV into the project.
  3. Import the OpenCV for Android SDK module in Android Studio.
    • To import the OpenCV SDK as a module in your project, go to File>New>Import Module.
    • Then Give path to your OpenCV as ..\OpenCV-android-sdk\sdk\java
    • You can chose to modify your module’s name.
    • Press Next and Finish the Dialogue.
    • The entire process is given here:
      OpenCV-Android-Import-Module-Android-Studio
    • Note that in the end, there are some errors in the code as well as the console. This is because you need to fix the Version number and link the libraries with your own project. This is shown in the next two steps.
  4. In this step, we will fix the Android Project SDK information in the OpenCV build.gradle file.
    • In project explorer, switch to Project view.
    • Go to OpenCVLibrary300 > build.gradle file and open it.
      • I have updated the contents of the file with the following code
      • Note that the android project’s SDK information can be obtained from the project’s own build.gradle file.
    • Once the Android SDK settings are updated, press “Try Again” button.
    • This entire process is given below:
      OpenCV-Android-Update-DefaultProject-SDK-Information
    • Now. we need to fix library association.
  5. Looking good so far! We now need to make sure that the OpenCV for Android libraries are associated with our Android Studio project. Currently, Android Studio will not recognize the OpenCV code that we type in our files. We fix this as follows.
    • Go to File>Project Structure.
    • When window opens, under Modules, select app.
    • Click Dependencies.
    • Click +.
    • Select Module Dependencies.
    • (In my case) Select :openCVLibrary300.
    • Press Ok and Ok.
    • After a few seconds, the libraries will be associated with your Android project.
    • This entire process is shown here:
      OpenCV-SDK-library-association
    • You can now write more OpenCV code in future in the same project.
  6. We did it! Project is ready for future OpenCV development.

This concludes this tutorial. You are now ready to start making your own Android Studio Project that consists of OpenCV SDK features limited only by your imagination. In the next tutorial, I will SHOW CAMERA on android app screen using OpenCV. Make sure that you read it. Do not forget to SHARE this post and write your opinions, ideas and views  in the  COMMENT  section below.

Thanks for reading :). Please like my Facebook page and follow my Twitter for more tutorials.

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OpenCV SDK for Android File Structure

OpenCV for Android SDK file structure

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In this tutorial, you will learn about the file structure of OpenCV SDK for Android. The information here is very short and lacks details. My purpose here is to provide just enough information to get going with the rest of the tutorials. I highly recommend reading more about the folders, algorithms, libraries and classes on your own.

OpenCV-for-Android-filestructure

So you have downloaded SDK but you may be curious what the SDK files do. Lets see to that now. You can skip this tutorial if you are interested in going directly to the development.

When you extract the “OpenCV-3.0.0-android-sdk-1.zip” from the precious tutorial, you will get a folder /OpenCV-android-sdk/.

Inside the /OpenCV-android-sdk/ folder, you will see:

  • /apk/
  • /samples/
  • /sdk/
  • LICENSE
  • README.android

Lets look at these in detail.

OpenCV for Android SDK file structure
OpenCV for Android SDK file structure
S.No
Name
Description

1

/apk/ This folder contains OpenCV manager API for different android device architectures. Chose the .apk file which is supported by your android device. Or simply download one from Google Play Store because that way, you will be downloading the apk file that is supported by your device/

2

/samples/ This folder contains sample android apps that you can install into your android device to test features of OpenCV. Also note that the source code of each sample is included in the /samples/ folder. It is a good place to start.

3

/sdk/ THE BRAINS OF OpenCV is here. I will explain about this folder below.

4

LICENSE Well, it can’t be said more precisely than what is written there as “By downloading, copying, installing or using the software you agree to this license.If you do not agree to this license, do not download, install,

copy or use the software.”

5

README.android Contains a link to online documentation, resources and feedback. Quiet handy!

http://opencv.org/platforms/android.html

Now that the root file structure of OpenCV is out of the way, we can now take a look at the SDK folder contents to give you the idea of what exactly what it and its contents do.

The /sdk/ folder contains the OpenCV API and libraries that will be used in your android project. You need these to perform all the functionalities that OpenCV offers in order to help you perform your Computer Vision related job.

Inside the SDK folder, in my case, there are three folders:

  1. /sdk/etc/
  2. /sdk/java/
  3. /sdk/native/

Lets look at the contents of SDK folder here:

S.No Name Description
1 /sdk/etc/ This folder contains the “memory” of OpenCV. Memory being like the brain-memory :D. See, as the time passed, the geniuses who made OpenCV for us to feast upon collected data and fine-tuned it for algorithms to use. That data is kept here.

For example, face detection requires some data which is compared with the picture snapped by your x-megapixel camera. That data is kept inside this folder.

2 /sdk/etc/haarcascades HAAR or HAAR-like-features is a folder where you put post-OpenCV-training data.

 

In this folder, you can find data files which contain data generated by training OpenCV in order to detect face, eyes, nose etc detection.

 

You too can create such data files if you wish to detect something such as legs, airplane, cracks on wall (edge detection), pacman, ****, *******, *******888*88* detection 😛

 

Lets say you wish to train OpenCV to detect face of a “sick” person. So you take pictures of a (e.g.) 1000 sick people (positive images) and then resize those picture to a same small size that is easy to process in bulk :D. Now you will also need pictures of people who are NOT sick.  Now, you will train OpenCV on that load of 1000 pictures plus the people who are not sick. This data is put in this folder to be used.

 

HAAR algorithm is very accurate but is slower as compared to LBP.

3 /sdk/etc/lbpcascades LBP stands for local binary pattern. This method is unique in a way that instead of using generated data to detect features (as was the case of HAAR), the LBP takes a pixel and finds the intensity of its neighbor pixels.

 

So lets say there is a pixel. Practically, each pixel has eight neighbor pixels, so our pixel also has eight surrounding pixels. Now, for each pixel, a binary value is obtained. The value of binary number depends on the comparison between the center pixel and its test-neighbor pixel.

 

If pixel intensity is greater than center pixel, then value is 1.

If pixel intensity is lesser than center pixel, then value is 0.

 

LBP algorithm is very fast, but least accurate.

4 /java/ When creating a new Android project, you can import the OpenCV Java Api from this folder.
5 /java/.settings Contains settings that are implemented when importing the OpenCV for android Java API.
6 /java/gen Contains generated files. For example, R.java, when generated is put here.
7 /java/javadoc This folder contains the documentation of OpenCV for Android. In my case, it is the documentation for the version 3.0.0

All the classes of OpenCV for Android are explained here. So if you ever find yourself in trouble, or wish to learn more, visit this folder.

8 /java/res Standard Android project folder that contains resources to be used in an android project. The resource file that came in my case contains camera information.
9 /java/src The /etc/ folder was the memory of OpenCV. But this folder is the actual brain of OpenCV. This folder contains the classes that perform all the functionalities of OpenCV in Android. Classes are written in Java.

 

Root files are self explainatory. If not, then what on Earth are you doing on this post? You should learn Android and then come here.

10 /java/src/org/opencv Exactly this folder contains the classes. Core, mathematical operation algorithm, training and all the shit that OpenCV gets done for you, is actually here. Every improvement in OpenCV is included here. Please respect the contents of this folder if you use OpenCV.
11 /native/ This folder contains C++ .h (header) files and native libraries for multiple android architectures.

This is it for this tutorial. I have explained to you the structure of the OpenCV for Android SDK file structure. In the next tutorial, I will explin to you about the classes available in OpenCV for Android SDK which you can use.

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OpenCV for Android: Download Required Software

OpenCV for Android Download-Required Software

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In this tutorial, you will learn which tools to download for creating your OpenCV project in Android Studio if you follow this tutorial series 🙂

  1. Download and install Android Studio from HERE. Make sure that it is working.
  2. Download  OpenCV for Android SDK from HERE.
    • Demonstration of SDK download.

      OpenCV for Android Download-Required Software
      OpenCV for Android Download-Required Software
  3. Basically, after downloading the SDK, simply extract it on a folder and it will be ready for usage.
  4. That’s it! You have downloaded the OpenCV for Android SDK.

In the next tutorial, you will make a new project and set it up so that your application is ready to OpenCV!

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