so, I m a bit confused here. I have an opencv project which import an image and does something with it and gives output.So I want to use this project as one part in my android project.So how do I proceed. I have SDK, NDK openCV lib all installed. Any help would be great.
Compile your project with NDK as a static library.
Create a shared library with JNI entry point that takes the necessary inputs from Java and return the result to Java. Link it with your static lib and OpenCV.
Create a Java Android project that uses this shared library.
Related
I have a project where we want to access to a finger print scanner (external scanner). The drivers are written in c++ (NDK).
does Native script support access to Native Components?
There are a several issues about that on NativeScript's repo on GitHub, all lead to this issue where the solution is to create an AAR file from the CPP file and load it from NativeScript.
I found also a detailed guide about how to do it, here are the main steps summarized by the author:
Create an Android library using Android Studio
Import the native C++ library and wrap the code we want to export into a Java class, using JNI
Export the library to a aar file, and import it into a new NativeScript plugin
Import the plugin into a new NativeScript application
How can I use '.a' static library built with NDK.
Where do I attach header files( include file ) to call a function.
My Android studio version is 2.23.
Thanks in advance.
A good place to start is the formal documentation, if you haven't tried it already. Here is the general page showing how to add a prebuilt library: Using Prebuilt Libraries
I have a project written in C++ and I want to build a static library to be able to link against it in other projects. But Android Studio along with NDK produces only shared library objects which are for me not usable (I need static objects). I use gradle plugin to build the code.
While the code compiles I cannot find a way to get a "libname.a" file.
Anybody knows the magic behind this in Gradle ?
While not well familiar with the NDK Gradle supports building native static libraries. You can see an example in C++ with Gradle or learn more about it in gradle user guide Native Binaries chapter.
I have developed an application for computer vision algorithms that uses Native C++ library like OpenCV to capture camera frame and do image processing. My whole implementation resides in a native function which is called through an activity.
Let's say:
public native int MYMETHOD(int width, int height,int[] rgba);
I also load my library like this:
static {
System.loadLibrary("MYNativeLIB");
}
Now my question is how can I deploy my application as a library package. Something deliverable that I can share it and the clients can import it to their project without installing any other libraries like OpenCV. Do I need to build a .so package?
I have read this article. But I do not know how can I link against OpenCV library as well.
Thanks for your help in advance.
You should have a look at the static initialization for OpenCV4andorid. You then can add the Open CV lib into your /libs directory of your Library project without the need to install any third party app when using it.
Have you created your project as a library? Maybe you could create a new project and port code with little effort. A very concise yet detailed explanation here:.
http://developer.android.com/tools/projects/projects-eclipse.html#SettingUpLibraryProject
First you need to compile c/c++ files using android-ndk detailed
explanation here
http://rathodpratik.wordpress.com/2013/03/24/build-cc-executables-for-android-using-ndk/
Then you can successfully run your android project.
I want to work on an Android project (under Eclipse) using Opencv, I've imported the Opencv library and it's associated samples to Eclipse, as explained here:
http://opencv.itseez.com/doc/tutorials/introduction/android_binary_package/android_binary_package.html.
I tested the samples and they work well. But when I create my new own Android project in Eclipse, it can't link Opencv which is placed in the same workspace as the project (i.e. error when I write import org.opencv.core.*).
Is there something that has to be done for a new project to be linked with Opencv (src and lib)?
I recomend you to download the OpenCV prebuild package and follow these instructions.
I don't know if you are going to use C++ for openCV and crosscompile with NDK and JNI library, but that way is quite easy to set up everything. If you need more help about how including C++ OpenCV codes in android projects I can check my codes. Good luck.
It sounds like you haven’t included the Open CV library’s in your new project.
I can’t remember the exact step to include libraries in projects but below are a couple of link that might help.
http://wiki.eclipse.org/FAQ_How_do_I_add_an_extra_library_to_my_project's_classpath%3F
Import Libraries in Eclipse?