OpenCV4Android | OpenCV4Android including various examples | Computer Vision library

by jiangdongguo C++ Version: Current License: No License

X-Ray Key Features Code Snippets Community Discussions(7)Vulnerabilities Install Support

kandi X-RAY | OpenCV4Android Summary

OpenCV4Android is a C++ library typically used in Artificial Intelligence, Computer Vision, OpenCV applications. OpenCV4Android has no bugs, it has no vulnerabilities and it has low support. You can download it from GitHub.

OpenCV4Android including various examples // OpenCV4Android开发实录应用示例集合

Support

Quality

Security

License

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Support

OpenCV4Android has a low active ecosystem.

It has 103 star(s) with 39 fork(s). There are 2 watchers for this library.

It had no major release in the last 6 months.

There are 6 open issues and 1 have been closed. There are no pull requests.

It has a neutral sentiment in the developer community.

The latest version of OpenCV4Android is current.

Quality

OpenCV4Android has 0 bugs and 0 code smells.

Security

OpenCV4Android has no vulnerabilities reported, and its dependent libraries have no vulnerabilities reported.

OpenCV4Android code analysis shows 0 unresolved vulnerabilities.

There are 0 security hotspots that need review.

License

OpenCV4Android does not have a standard license declared.

Check the repository for any license declaration and review the terms closely.

Without a license, all rights are reserved, and you cannot use the library in your applications.

Reuse

OpenCV4Android releases are not available. You will need to build from source code and install.

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OpenCV4Android Key Features

No Key Features are available at this moment for OpenCV4Android.

OpenCV4Android Examples and Code Snippets

No Code Snippets are available at this moment for OpenCV4Android.

Community Discussions

Trending Discussions on OpenCV4Android

How to remove unresolved reference error using OpenCV4 with Android Studio(kotlin)

How to pass PNG from Java class to Native class in Android with Opencv

Output image after Grabcut algorithm appears all black nothing init

Display byte as unsigned

Opencv4Android getPerspectiveTransform error

OpenCv Core.line draws white when color is expected

Linking shared library in Android project

QUESTION

How to remove unresolved reference error using OpenCV4 with Android Studio(kotlin)

Asked 2019-Jun-03 at 03:32

I'm trying to convert java code into kotlin. Original java code is shown in that page(Edit: @OpenCV4Android) android java opencv 2.4 convexhull convexdefect

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ANSWER

Answered 2019-Jun-03 at 03:32

I worked out the problem by myself.

Source https://stackoverflow.com/questions/56393622

QUESTION

How to pass PNG from Java class to Native class in Android with Opencv

Asked 2019-May-24 at 20:05

I want to pass a PNG format image file to native class to perform alpha-blending using OpenCV. For that I need all the 4 channels of the PNG. The image file that I want to pass is in my assets folder. I would like to know what is the best way to pass it to the native class? Thank you.

I'm using with Android Studio 3.3.2 and OpenCV4Android 4.1.0

...

ANSWER

Answered 2019-May-24 at 20:05

You can always serialize the image to bytes and pass it to JNI code. There, inside JNI, you can deserialize it.

http://jnicookbook.owsiak.org/recipe-No-007/

You can also pass object and extract it's fields inside JNI. But this will require some tweaking on JNI side

http://jnicookbook.owsiak.org/recipe-No-020/

Anyway, at some point, you will have to access data from Java and turn it into C/C++ format (e.g. structures used by OpenCV).

If you have access to the file, you can also pass location of the file (String) and read the file inside C/C++ code

http://jnicookbook.owsiak.org/recipe-No-009/

Source https://stackoverflow.com/questions/56202547

QUESTION

Output image after Grabcut algorithm appears all black nothing init

Asked 2018-Jun-03 at 04:33

I had followed this tutorial to apply grab cut algorithm in opencv4android but my output image is not same as described in this tutorial. In fact the image I get is only black.

The output I get is this image Output image. I use same image used toturial as input but my output was black.

...

ANSWER

Answered 2018-Jun-02 at 15:20

Here is the code for grabcut in android opencv that solves your problem.

Source https://stackoverflow.com/questions/50658275

QUESTION

Display byte as unsigned

Asked 2017-Dec-11 at 16:32

I'm building an Android app using OpenCV4Android. For manipulating some images I work with (i.e Mat objects), I convert them into a byte[] (using the get method). My problem is that the values of this array appear as unsigned bytes, which makes it really hard to debug:

Is there a way to overcome this and display the array's values as unsigned bytes?

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ANSWER

Answered 2017-Dec-11 at 16:32

Java does not supply an unsigned byte primitive. For debugging purposes, you could copy each byte to an int[] (being sure to avoid negative values) and view the int[]. That's a kludge, but that's about the closest solution.

Simply assigning byte to int will preserve the sign, and so will using a cast. Use

Source https://stackoverflow.com/questions/47756627

QUESTION

Opencv4Android getPerspectiveTransform error

Asked 2017-Jun-20 at 08:44

I want to use getPerspectiveTransform function, but it only accepts Mat as arguments and I have coordinate data in an array. So I convert them into points and then to Mat as follows:

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ANSWER

Answered 2017-Jun-20 at 08:44

As mentioned in the comment discussion on OP's post (all credit to them), the problem lies with the list l:

Source https://stackoverflow.com/questions/44642398

QUESTION

OpenCv Core.line draws white when color is expected

Asked 2017-Jun-04 at 08:37

In an OpenCv4Android environment, when I create a Mat image and use Core.line() to draw on the image, it always shows a white instead of the color I specify.

I have seen a question related to gray scale, but the image I have has not been converted to gray.

...

ANSWER

Answered 2017-Jun-04 at 08:37

The problem is with the color you have initialized

Source https://stackoverflow.com/questions/44349358

QUESTION

Linking shared library in Android project

Asked 2017-Apr-28 at 07:01

I need to import a single function written in a C file in an android studio project. This function call others functions located in anothers files (50+ C files and headers in total).

This project already contains a single C++ file as I am using NDK to compile OpenCV4android.

I've used Mingw and GCC to compile a shared libraries (libfinal.so) but once i try to import them thanks to NDKbuild i got this meaningless error :

...

ANSWER

Answered 2017-Apr-28 at 07:01

Your hierarchy is wrong. Follow these steps:

Create 'lib' folder in jni folder and put your shared libraries according target folders. This should look like: 'jni/lib/armeabi-v7a/libfinal.so'.
Prebuilt only these .so libs which are in jni/lib folder. For this, change this line LOCAL_SRC_FILES := libfinal.so to LOCAL_SRC_FILES := lib/$(TARGET_ARCH_ABI)/libfinal.so. This will search lib folder in jni folder, and then this will search libfinal.so lib in targetted folder according your cpu architecture.
Be aware of your gradle scripts. You should add your Android.mk file like this,

Source https://stackoverflow.com/questions/43663633

Community Discussions, Code Snippets contain sources that include Stack Exchange Network

Vulnerabilities

No vulnerabilities reported

Install OpenCV4Android

You can download it from GitHub.

Support

For any new features, suggestions and bugs create an issue on GitHub. If you have any questions check and ask questions on community page Stack Overflow .

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