How to detect rectangle from image and crop from it's four edges?
Hello all, I am developing an application for detect driving license and capture image of driving license using surface view and detect driving license and crop from those it's four corner using...
View ArticleEye gaze detection in android
I'm looking to perform real time gaze tracking using the front camera of an android phone. My goal is to track the user's gaze while the user moves his head from left to right and right to left tries...
View ArticleHow to extract signature from driving license card?
Hello, I am developing license verification application in android. So right now i want to extract signature from different driving licenses front side using OpenCV in android. Please suggest any best...
View ArticleRemove background from canny image in android opencv
Hello, i want remove background from captured image. As of now i am capture usa driving license image and convert it into canny image. Here bellow is my output image so i want to remove rest of all...
View ArticleRed color detection not happening on white paper.
I am facing issue regarding red color detection on white paper. As it seems like the red range vary device to device for detecting red color on white paper. On other colors the detection is working...
View ArticleBuild for Android
I'm trying build for Android. And have error: [ 56%] Linking CXX shared library ../../lib/armeabi-v7a/libopencv_freetype.so...
View ArticleAruco java, trying to get marker IDs
Hi all, first of all thanks for this amazing library. I´m working on my final degree project, using a Lego Mindstorm EV3 that uses my Android phone camera as its eyes. I´ve implemented an android app...
View ArticleWhy is my JavaCameraView is squeezed vertically?
This is what the JavaCameraView looks like, my face is squeezed:  I use this code to achieve this effect: /** * Do processing after frame grabbing...
View Article[Android package] FIXME in MatOfDMatch.java file & features number extracted
Hi, Im building an Android app, using opencv 3.4.5 version.(with Android studio ). I have two questions: 1. In openCV 3.4.5, Android package, in the file "MatOfDMatch.java", the following comment...
View ArticleCopy smaller mat to part of bigger mat
Hello everyone, I have a mat1 (320x100), that I want to copy to a part of a bigger mat2 (320x480), so mat1 starts at (0, 75) from mat2 and ends at (320, 175). How do I do this? I would also like to...
View ArticleObject Detection and Tracking on Android
Hi, I am about to embark on a bit of a journey into Computer Vision. My Goal is to track a single (but changeable) Object in the CameraPreview of an Android Phone. I have done some research online...
View ArticleOpenCV manager 2.4.9 incompatible with Android 8.0
I am trying to get an Android app written back in 2014 back to work. The app uses OpenCV 2.4.9, therefore requiring OpenCV manager 2.4.9. However, all the manager apks in the *apk* directory of the...
View ArticleResize image, compute, resize back to original
Hello, This might seem like a simple issue but here is what I need help with: 1. for example I receive a 1280*960 image, I then resize it to 640*480 or 320*240 pixels 2. I do some processing and I end...
View ArticleHand-drawn marker?
Hi! I'm totally new with OpenCV and I am trying to make an android app which would target a hand-made marker on the skin of the user (something simple, like a square or similar that the usr could draw...
View ArticleOpenCV is not detecting rectangle(paper) In some Devices like moto,oppo devices
I have integrated latest version of opencv(4.1.0) for rectangle(Paper) detection but it is unable to detect rectangle(paper) in some devices like moto,oppo devices. also it is only detecting rectangle...
View ArticleCanny Edge Detector doesn't return filtered image
I building an APK that receive the image from my android device camera and process with OpenCV library. Just want to *convert the image to Gray scale, apply Gaussian Blur filter and run Canny Edge...
View ArticleWhats I need to do for integrate Color Moments and FLANN using OpenCV?
I have a project here that I need to identify leaves of unhealthy plants. For this I will extract features color, texture and outline from image for after to compare with a database, But I don't know...
View ArticleProblem with video on 32 bit Android sdk
I'm using the Android sdk libopencv_java4.so library. The 64 bit arm64-v8a version is working fine but the 32 bit armeabi-v7a version is making my application crash when I use cv::VideoCapture(s) when...
View ArticleDetect green laser dot
 how to detect this green laser dot using android openCV
View ArticleMoments have reading of 0.0 in Android Q 10.0
**System information (version)** OpenCV => 4.1.0 Operating System / Platform => Android Compiler => Android Studio I am trying to get moments, but all reading reads 0.0 for all elements in the...
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