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cannot load image on android

Every time I try to run template match function in android studio, I get Assertion failed error. I have started to debug and my img.cols() and img.rows() is always 0. Some kind of empty matrix is...

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how to find all the objects in the picture with one template using opencv and...

i tried to do a code that find all objects using a template .The logCat don't give me any errors but the application stopped this is the code .Please help me public Mat matchTemplate(String inFile,...

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Segfault when using add on Android

What I'm essentially trying to do is: L = (17.8824 * r) + (43.5161 * g) + (4.11935 * b) The code I'm using for that is essentially: Mat rgb = inputFrame.rgba(); List rgbSplit = new ArrayList(3);...

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Hough transform in OpenCV4Android

Hi guys, I'm stuck again on my app, i.e. detecting boxes on shelf. now I am starting to use simpler photos, with foreground (boxes) is different from background: colored boxes on white or black...

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in android, to show an image using opencv, where should i create the Mat object?

I dont know in what place i need to do it, I know that not in onCreate, but i dont know where yes.

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Why the trained model's performance is not the same while running on PC and...

Hi, I have trained a cascade classifier for a particular object. The classifier is supposed to be used in android app. For testing purposes I've written a python script and the model performance...

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how to use Opencv machine learning for android project (KNN or SVM algorithms)?

I need your help .I am a beginner in opencv and i should recognize letters in an image taken by android camera .I should use opencv machine learning such us KNN or SVM .I searched a lot but i don't...

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process of ORB algorithm in OpenCV

Dear great OpenCV community I am a computer science bachelor student. Presently, I am using OpenCV 3.0.0 and Android Studio to make an markerless augmented reality android app for my thesis. For the...

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Android - Opencv - error: (-215) u != 0 in function void cv::Mat::create

My app keeps crashing with this error FATAL EXCEPTION: Thread-22883 Process: com.aar.Cline, PID: 7270 CvException [org.opencv.core.CvException: cv::Exception:...

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OpenCV4Android - calcCovarMatrix for image averages

So I have two RBG averages that I want to get a Mahalanobis distance for but the Mahalanobis function requires an inverse co-variance matrix. My question is how do I create a inverse co-variance matric...

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SimpleBlobDetector in opencv for android

Helle everyone! I'm quite new to opencv , so I'm having a hard time tring to use the class SimpleBlobDetector in my Android project (OpenCV library 300) . I don't know how to create the detector. All...

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Error when tring to train image with opencv and android

public class MainActivity extends Activity { Button button; ImageView res4; TextView T1; private static final String TAG = "training"; private BaseLoaderCallback mLoaderCallBack = new...

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How to put a label of type string in a matrix (KNN)

This line put a label for a trainData mat train_labels.push_back(new Mat (1,1,CvType.CV_32FC1,new Scalar(i))) I would put a string label instead of a float label .is it possible ?

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How to hide camera in opencv android 3.0?

Hi, I am trying to hide camera display in opencv3.1.0 android/java. I have CameraBridgeViewBaseif I set its visibility to GONE or Invisible OnCameraFrame method is not firing in my activity. And if...

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findEssentialMat gives wrong results in android

Hi, I am trying to create a visual odometry app for android using NDK. I am using FAST and KLT and then using findEssentialMat to find the essential matrix. However, it is giving erroneous results....

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Use OpenCV without any external installation Android

Hi, I'm using OpenCV on Android devices. I have 2 kinds of problem using OpenCV libraries: 1. If I'm trying to download the OpenCV package by using the apk file, The user interrupted twice, first, he...

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Unity mobile camera lag Facetracking

I´m trying to build a facetracking app, but when the camera track the face with FaceTrackerARSample script, the fps are very low and it´s impossible to run it without lag. I play it on android device...

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Android QR code detection/extraction using OpenCV

I am trying to develop an android application to decode QR codes, however i do not want to use libraries such as zxing, i must implement it. The main problem i am having is how to perfectly extract a...

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which method is better SVM,KNN or neural network for letters recognition

i have to recognize letters in a picture taken with android camera and i should use machine learning .I can't choose the best method .

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How to recognize all the letters in a picture with opencv , KNN and java

i have to write a java program that recognizes all the letters in a picture taken with android camera .I tried KNN method but i could only recognize a single letter in the picture and i want to...

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