使用 Android 的 OpenCV 人脸识别

Question

I am very new to android, as I got a project for maintenance. I completed other part of the project like authentication, token setting etc... In that face recognition is used to identify the person.

Previously it was working fine and taken images, trained with it and recognized the person.(Obviously not done by me :)). Now it throws error as

Add Person ActivityCvException [org.opencv.core.CvException: cv::Exception: /build/master_pack-android/opencv/modules/core/src/matrix.cpp:1047: error: (-13) The matrix is not continuous, thus its number of rows can not be changed in function cv::Mat cv::Mat::reshape(int, int) const

Code sample is as follows

public void training() { Thread thread; try{ PreferenceManager.setDefaultValues(getApplicationContext(), R.xml.preferences, false); }catch (Exception e){ AddPersonActivity.this.runOnUiThread(new Runnable() { public void run() { WriteLog("Add Person Activity" +e.fillInStackTrace()); errorAlert("Add Person Activity" +e.fillInStackTrace()); VolleyHelper.progressDialog.dismiss(); } }); } WriteLog("training 1 "); final Handler handler = new Handler(Looper.getMainLooper()); thread = new Thread(new Runnable() { public void run() { if (!Thread.currentThread().isInterrupted()) { try { WriteLog("training 2 "); PreProcessorFactory ppF = new PreProcessorFactory(AddPersonActivity.this); PreferencesHelper preferencesHelper = new PreferencesHelper(AddPersonActivity.this); String algorithm = preferencesHelper.getClassificationMethod(); FileHelper fileHelper = new FileHelper(); fileHelper.createDataFolderIfNotExsiting(); final File[] persons = fileHelper.getTrainingList(); if (persons.length > 0) { Recognition rec = RecognitionFactory.getRecognitionAlgorithm(getApplicationContext(), Recognition.TRAINING, algorithm); for (File person : persons) { if (person.isDirectory()) { File[] files = person.listFiles(); int counter = 1; for (File file : files) { if (FileHelper.isFileAnImage(file)) { Mat imgRgb = Imgcodecs.imread(file.getAbsolutePath()); Imgproc.cvtColor(imgRgb, imgRgb, Imgproc.COLOR_BGRA2RGBA); Mat processedImage = new Mat(); imgRgb.copyTo(processedImage); List<Mat> images = ppF.getProcessedImage(processedImage, PreProcessorFactory.PreprocessingMode.RECOGNITION); if (images == null || images.size() > 1) { continue; } else { processedImage = images.get(0); } if (processedImage.empty()) { continue; } String[] tokens = file.getParent().split("/"); final String name = tokens[tokens.length - 1]; for (int i = 0; i < files.length; i++) { File myfile = new File(person + "\\\\" + files[i].getName()); String long_file_name = files[i].getName(); System.out.println(long_file_name); System.out.print(long_file_name); myfile.renameTo(new File(person + "\\\\" + long_file_name + "_101" + ".png")); } WriteLog("training 3 "); MatName m = new MatName("processedImage", processedImage); fileHelper.saveMatToImage(m, FileHelper.DATA_PATH); rec.addImage(processedImage, name, false); counter++; } } } } try { if (rec.train()) { if (zipFileAtPath("/storage/emulated/0/Pictures/facerecognition/training/" + lcode, "/storage/emulated/0/Pictures/facerecognition/data/SVM/" + lcode + ".zip")) { WriteLog("training 4 "); if (zipFileAtPath("/storage/emulated/0/Pictures/facerecognition/data/SVM", "/storage/emulated/0/Pictures/facerecognition/" + "SVM_" + lcode + ".zip")) { WriteLog("training 5 "); fileupload(getintent.getStringExtra("lcode")); } else { Toast.makeText(getApplicationContext(), "No Face Recognised", Toast.LENGTH_SHORT).show(); } } else { Toast.makeText(getApplicationContext(), "No Face Recognised", Toast.LENGTH_SHORT).show(); } } else { Toast.makeText(getApplicationContext(), "Try Again", Toast.LENGTH_SHORT).show(); } } catch (Exception e) { WriteLog("Add Person Activity" +e.fillInStackTrace()); errorAlert("Add Person Activity" +e.fillInStackTrace()); } handler.post(new Runnable() { @Override public void run() { } }); } else { Thread.currentThread().interrupt(); } } catch (Exception e) { AddPersonActivity.this.runOnUiThread(new Runnable() { public void run() { VolleyHelper.progressDialog.dismiss(); WriteLog("Add Person Activity" +e.fillInStackTrace()); errorAlert("Add Person Activity" +e.fillInStackTrace()); } }); } } } }); thread.start(); }

Answer 1

The input image needs to be stored as a continuous block of bytes in memory. I came to a similar situation, particularly because Android (at least the version I tried) does not seem to store images continuously. 1) Check if the image is continuous using: inputImage.isContinuous() . It returns a bool . It should be true . 2) If the image is not continuous, you can create a copy of the image that it is by creating a clone of the image via inputImage.clone() . Behind the scenes, we are creating a deep copy of the input using the create method, that should guarantee that the new matrix is continuous.

 //check image before continuing:
 if ( !inputImage.isContinuous() ){ 
    //if the image is not continuous, create a deep copy:
    inputImage = inputImage.clone();
 }