Not able to copy trained files for english ,hindi from asset folder to my mobile device

Question

I am using tess two android libraries for converting any language in image to text...however I copied trained files of English and Hindi from https://github.com/tesseract-ocr/tessdata_best in my asset folder inside app directory. However it is able to copy ben.traineddata to mobile device but for english and hindi traineddata it gives me following error - Data file not found at /storage/emulated/0/Android/data/com.android.application/files/tessdata/mar.traineddata

Here's my code -

package com.android.application;

import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import androidx.core.content.FileProvider;

import android.Manifest;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.res.AssetManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import com.googlecode.tesseract.android.TessBaseAPI;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.text.SimpleDateFormat;
import java.util.Date;

public class tessTwo extends AppCompatActivity {
    public static final String TESS_DATA = "/tessdata";
    private static final String TAG = MainActivity.class.getSimpleName();
    private static final String DATA_PATH = Environment.getExternalStorageDirectory().toString() + "/Tess";
    private TextView textView;
    private TessBaseAPI tessBaseAPI;
    private Uri outputFileDir;
    private String mCurrentPhotoPath;
    Button bo;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_tess_two);


        textView = this.findViewById(R.id.textView);
        bo = findViewById(R.id.buttoi);

        // final Activity activity = this;
        checkPermission();
        bo.setOnClickListener(new View.OnClickListener() {
            private Object Context;

            @Override
            public void onClick(View v) {
                checkPermission();

                dispatchTakePictureIntent();
                Log.e("Data path",DATA_PATH);
            }
        });

    }

    private void checkPermission() {
        if (ContextCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 120);
        }
        if (ContextCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 121);
        }
    }


    private void dispatchTakePictureIntent() {
        Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        // Ensure that there's a camera activity to handle the intent
        if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
            // Create the File where the photo should go
            File photoFile = null;
            try {
                photoFile = createImageFile();
            } catch (IOException ex) {
                // Error occurred while creating the File
            }
            // Continue only if the File was successfully created
            if (photoFile != null) {
                Uri photoURI = FileProvider.getUriForFile(this,
                        BuildConfig.APPLICATION_ID + ".provider",
                        photoFile);
                takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
                startActivityForResult(takePictureIntent, 1024);
            }
        }
    }

    private File createImageFile() throws IOException {
        // Create an image file name
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        String imageFileName = "JPEG_" + timeStamp + "_";
        File storageDir = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
        File image = File.createTempFile(
                imageFileName,  /* prefix */
                ".jpg",         /* suffix */
                storageDir      /* directory */
        );

        // Save a file: path for use with ACTION_VIEW intents
        mCurrentPhotoPath = image.getAbsolutePath();
        return image;
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == 1024) {
            if (resultCode == Activity.RESULT_OK) {
                prepareTessData();
                startOCR(outputFileDir);
            } else if (resultCode == Activity.RESULT_CANCELED) {
                Toast.makeText(getApplicationContext(), "Result canceled.", Toast.LENGTH_SHORT).show();
            } else {
                Toast.makeText(getApplicationContext(), "Activity result failed.", Toast.LENGTH_SHORT).show();
            }
        }
    }

    private void prepareTessData(){
        try{

            File dir = getExternalFilesDir(TESS_DATA);
            Log.e("dir:",dir.toString());
            if(!dir.exists()){
                if (!dir.mkdir()) {
                    Toast.makeText(getApplicationContext(), "The folder " + dir.getPath() + "was not created", Toast.LENGTH_SHORT).show();
                }
            }
            String fileList[] = getAssets().list("");

            for(String fileName : fileList){
                String pathToDataFile = dir + "/" + fileName;
                if(!(new File(pathToDataFile)).exists()){
                    Log.e("Path to dta:",pathToDataFile);
                    InputStream in = getAssets().open(fileName);
                    Log.e("in:",in.toString());

                    OutputStream out = new FileOutputStream(pathToDataFile);
                    byte [] buff = new byte[1024];
                    int len ;
                    while(( len = in.read(buff)) > 0){
                        out.write(buff,0,len);
                    }
                    in.close();
                    out.close();
                }
            }
        } catch (Exception e) {
            Log.e("Na mile", e.getMessage());

        }
    }

    private void startOCR(Uri imageUri){
        try{
            BitmapFactory.Options options = new BitmapFactory.Options();
            options.inJustDecodeBounds = false;
            options.inSampleSize = 6;
            Bitmap bitmap = BitmapFactory.decodeFile(mCurrentPhotoPath, options);
            String result = this.getText(bitmap);
            textView.setText(result);
        }catch (Exception e){
            Log.e(TAG, e.getMessage());
        }
    }

    private String getText(Bitmap bitmap){
        try{
            tessBaseAPI = new TessBaseAPI();
        }catch (Exception e){
            Log.e(TAG, e.getMessage());
        }
        String dataPath = getExternalFilesDir("/").getPath() + "/";
        tessBaseAPI.init(dataPath, "mar");
        tessBaseAPI.setImage(bitmap);
        String retStr = "No result";
        try{
            retStr = tessBaseAPI.getUTF8Text();
        }catch (Exception e){
            Log.e(TAG, e.getMessage());
        }
        tessBaseAPI.end();
        return retStr;
    }
}

I have given required permissions in my device, still it's not working

The full error - 2019-12-31 13:33:55.918 23792-23792/com.android.application E/MainActivity: Data file not found at /storage/emulated/0/Android/data/com.android.application/files/tessdata/eng.traineddata

Also I get this error sometimes - Could not initialize Tesseract API with language=eng!

Answer 1

This is what worked for me, hope it be of help to you or any other person. Make sure the files are in the assets folder, not in a subfolder. Also make sure you are handling

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

permissions on the device as required.

private void copyAssets() {

File parent_data_path = new File(getExternalFilesDir(null)+"/tessdata");

            boolean isCreated;
            if(!parent_data_path.exists()){
                isCreated = parent_data_path.mkdir();
            } else {
                isCreated = true;
            }

            if(!isCreated){
                Toast.makeText(this, "Failed creating parent path", Toast.LENGTH_LONG).show();
                finish();
                return;
            }

            AssetManager assetManager = getAssets();
            String[] files = null;
            try {
                files = assetManager.list("");
            } catch (IOException e) {
                Log.e("tag", "Failed to get asset file list.", e);
            }

            if (files != null) for (String filename : files) {
                InputStream in = null;
                OutputStream out = null;
                try {

                    in = assetManager.open(filename);
                    File outFile = new File(parent_data_path, filename);
                    if(!outFile.exists()){
                        out = new FileOutputStream(outFile);
                        copyFile(in, out);
                    } else {
                        Log.e(TAG,"Already created at: "+outFile.getPath());
                    }

                } catch(IOException e) {
                    Log.e("tag", "Failed to copy asset file: " + filename, e);
                }
                finally {
                    if (in != null) {
                        try {
                            in.close();
                        } catch (IOException e) {
                            // NOOP
                        }
                    }
                    if (out != null) {
                        try {
                            out.close();
                        } catch (IOException e) {
                            Log.e(TAG,"Something here");
                        }
                    }
                }
            }
        }

Files copy method

private void copyFile(InputStream in, OutputStream out) throws IOException {
        byte[] buffer = new byte[1024];
        int read;
        while((read = in.read(buffer)) != -1){
            out.write(buffer, 0, read);
        }
    }

Then initialize the API like this

tessBaseAPI.init(getExternalFilesDir(null).getPath(), "mar");