Detect head using Haar Cascade, wont detect tilted head?
Hi all, I am very new to OpenCV and computer vision. However I have managed to make a simple android app that detects faces/eyes. I have designed a template that draws around the face, eyes, pupils...
View Articleandroid opencv optical mark recognition
I want to use opencv for OMR sheet or Bubble sheet .I dont have fix number of questions or columns in my omr sheet so i am trying to detetct rows and column (also i need to detect the title of the...
View ArticleAndroid dnn in native C++
Hello, i succesfully linked opencv to my android c++ native app.. now I encountered a problem where i cannot read my models (ex. YOLO) I pasted them here: */storage/emulated/0/DCIM/ * but when running...
View ArticleHow to rotate putText from the Android studio.
I accidentally set the screen horizontally. So the letters look horizontal. I want to know how to rotate the letters From the Android studio. putText(matInput, "R:2", Point(150, 320), 1, 8,...
View ArticleAndroid app Force closed by memory leak
Hey everyone. I'm trying to build a app,which can detect red color form input image , and do Hough line transform ,after sent the result to screen. i think i finish the program,but the program will be...
View ArticleImported module not shows up on 'Add Module Dependency' dialog
So I'm trying to add OpenCV as a dependency for my Android Studio project. And I've followed this tutorial https://github.com/davidmigloz/go-bees/wiki/Setup-OpenCV-3.1.0-in-Android-Studio-2.2 . So at...
View ArticleI can't find the alphamat module in the Android SDK releases 4.4.0.
I have been trying to use Alphamt, information flow function. I have downloaded the built from the following link where most of the contrib library is present but not the 'alphamat' module. How can I...
View ArticleIdentificar plantas mediante imágenes
Buen dÃa quisiera saber si con opencv puedo detectar que tipo de planta es en base a una fotografÃa. Deseo desarrollar con android un aplicativo que haga la identificación del tipo de planta
View ArticleOpenCV modules 3rd-party dependencies
Hello, I am relatively new to OpenCV (using 4.3.0) and i am trying to make a tiny version of it for and Android application, with only core, imgproc and imgcodecds module imported so that the library...
View Articlerequest help,Status -43: CL_INVALID_BUILD_OPTIONS
compile opencv-4.4.0, opencv_contrib-4.4.0 with opencl enable cmake_vars = dict( CMAKE_TOOLCHAIN_FILE=self.get_toolchain_file(), CMAKE_BUILD_TYPE="Debug", INSTALL_CREATE_DISTRIB="ON", WITH_OPENCL="ON",...
View ArticleOpenCV(3.4.11) Error: Unspecified error (Number of input channels should be...
I mauising opencv 3.4.11 for android. I get this error when i used the forward of Net function: Mat imageBlob = Dnn.blobFromImage(frame, 0.00392, new Size(416,416),new Scalar(0, 0, 0),/*swapRB*/false,...
View Articleandroid Aruco. Cannot detect corners ?
Hi i am new to OpenCV and trying to to detect aruco marker from https://chev.me/arucogen/ but corner.size() always returns 0 This is the code public Mat...
View ArticleOpenCV for Android will not compile
I'm having trouble getting OpenCV to compile with the Android toolchain. I can compile opencv for Linux just fine with or without contribs, but when I attempt to compile using the android toolchain,...
View ArticleWhere to find example for OpenCV on Android
Hi, OpenCV on android is quite different from the C++ version. Data in method are not the same. The vector as change to Mat. So it is quite difficult to use it without any documentation on the use of...
View Articlebuild opencv with java wrapper for android
Hi, I added some functionality in the chessboard.cpp and I can compile it on windows using VS2017. My final end is to use this added functionality on Android, so I need to compile OpenCV with java...
View ArticleBuild statically, missing cv::countNonZero(cv::_InputArray const&)
I am missing quite a few references: libopencv_imgproc.a(filter.dispatch.cpp.o):filter.dispatch.cpp:function cv::preprocess2DKernel(cv::Mat const&, std::__ndk1::vector,...
View ArticleConvert Python Into Java / Kotlin using these operations
I'm totally new in OpenCV. Does anyone knows how to convert below Python into Java/Kotlin? Only these a bit tricky to translate it. diff=cv2.subtract(img1, img2) diff[abs(diff)<30]=0 gray =...
View ArticleVideo writer in java not saving
Hello all, I want to record the frames I'm processing in my android smarthpone but nothing is being saved. I'm not getting any error either... First I created the object in the **MainActivity**: >...
View ArticleHow to change color of all non transparent pixels to black?
I use OpenCV (Java) and I want to change color of all the non transparent pixels in my Mat to black (colors defined in ARGB_8888 but could be another format) How can I do that ? Mat mat = new Mat();...
View ArticleCan not build single dynamic library (libopencv_java4.so) for Android
I am on Mac and trying to build the dynamic library for some of the modules and finally create a single .so file for Android. I have downloaded and built from source (Opencv release 4.5.0). The static...
View Articleopencv 4.5.0 cvDiv/cvMat equivalent ?
System information (version) OpenCV => 4.5.0 Operating System / Platform => MacOS Compiler => Android Studio with ndkBuild Detailed description I am developing and android app, I am using...
View ArticleUse build_sdk.py to build opencv4 for android on Windows
Hi, I need to build OpenCV for Android on Windows10. The OpenCV version is 4.4 and the command I use is: opencv-master\platforms\android\build_sdk.py...
View ArticleAndroid OpenCV + camera is just showing black screen
I've spent days (well, nights) trying to work this out. So many examples online are for different versions of Android Studio, different versions of Android, different versions of OpenCV and I can't get...
View ArticleCan I use OpenCV Android for commercial sales [2020]?
So I have an app built on traditional android, when I check the licensing for OpenCV it has: OpenCV 4.5.0 and higher versions are licensed under the Apache 2 License. Or if I use the older version...
View ArticleDidn't find class "android.view.JavaCameraView" on path: DexPathList[[zip...
Hello , please help me with the following error. I am doing a sample project using Open Source Computer Vision Library for Android. I imported module OpenCV-3.0.0-android-sdk-1 and created jniLibs...
View ArticleOpenCV with android not detecting image blur
I have downloaded opencv and integrated in android, https://brainhub.eu/blog/opencv-react-native-image-processing/ Even i capture blur image, i am not getting image as blur from open cv,...
View ArticleReduce frame resolution
I have android studio app and I need to access the camera and do some real-time processing to the video frames. I have tried to use **onCameraFrame()** method, the problem is that the process I do to...
View ArticleMobile app crashes when detecting facial landmarks
Hi, Recently github enabled opencv's extra classes through Python-for-android (including the face class). It has no trouble detecting the face binding boxes. It loads the LBF model, but then crashes...
View ArticleDoes OpenCV 4.3 support video capture from android?
I know that versions below 4.1 did not support and always returned an error, but in 4.1.1 support was added. *"VideoCapture C++ interface supports Android Media NDK (21+) video I/O file capture...
View ArticleError to cross compile into arm64-v8a by CV 4.3.0
I use CMake-GUI with Newest NDK 21.2.6472646 on Windows 10. If I remove BUILD_opencv_java, CMake will finish. [ 98%] Built target gen_opencv_java_source [ 98%] Linking CXX shared module...
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