Android-opencv-native-samples

OpenCV repository samples with cmake and lldb integration for latest android studio versions.

prequisites

• Android studio 2.3.3.
• Cmake support for android studio
• LLDB support for android studio
• C++ support for android studio
• Opencv 3.3 Android sdk version

How to install:

• clone the repository

git clone https://github.com/uelordi01/Android-opencv-native-samples.git

• file->open->project in android studio
• Find local.properties file in the project and add the opencv sdk dir as this snippet (looks like this).

ndk.dir = /home/your_user/android-sdk/ndk-bundle
sdk.dir = /home/user/android-sdk

So add this line in local.properties:

opencv.dir = you_opencv_sdk_dir

• Click on gradle sync button.

Features:

• Opencv gradle compliant
• CMake integration.
• c++ support integration
• lldb easy c++ debugging.

Gradle Configuration

• buildToolsVersion 26.0.0
• compileSdkVersion 25
• gradle version 3.3

Prerequisites

• Cmake support for android studio
• LLDB support for android studio
• C++ support for android studio

Samples:

• FaceDetection: Opencv face detection sample comparing two methods java + c++ and only java.

FAQ:

Why my camera image is upside down or mirrored?

This code is not prepared to take into account the smartphone camera position, I mean, there are some mobile phones that they have the camera on the left or on the right. Depending on that you image could be rotated or flipped.

Why the camera shows me rotated image when I put in portrait mode?

Yeah, the code is not still prepared to this this kind of rotations, so for now we will work in portrait mode.

Why gradle says that there is an error with the app compat library?

This is a gradle compatibility issue, that could be figured out putting the latest sdk in the compiledVersion

compile 'com.android.support:appcompat-v7:25.3.1'

the 25.3.1 number has to coincide with your sdk compile version.

android {
    compileSdkVersion 25
    ......
  }

TIPS:

Would you like to change the camera from the front to back?

Just go to the res/layout folder and find the layout which corresponds to the activity. Later find this layout element:

    <org.opencv.android.JavaCameraView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        app:camera_id="front"
        app:show_fps="true"
        android:id="@+id/fd_activity_surface_view" />

and change the app:camera_id:

    app:camera_id="back"

Would you like to show the fps in the camera layout?

Just go to the res/layout folder and find the layout which corresponds to the activity. Later find this layout element:

    <org.opencv.android.JavaCameraView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        app:camera_id="front"
        app:show_fps="false"
        android:id="@+id/fd_activity_surface_view" />

and change the app:show_fps

    app:show_fps="true"