Android：如何在不拍照的情况下从相机捕获文本？

Question

我想使用 tess-two（在 android 和 eclipse 中）捕获用相机显示的文本和数字而不拍照。 我不想保存图像文件。

类似这样的东西（它在相机上实时捕捉）：

我用过 tess-two ，但我必须先拍照，然后再捕捉文字。 （使用链接：https://stackoverflow.com/questions/19533273/best-ocr-optical-character-recognition-example-in-android）

我已经使用这个 (https://www.codeproject.com/Articles/840623/Android-Character-Recognition) 来创建我上传的图片之类的行为，但它也应该拍照。

那么我该如何实现呢？有可能吗？

Answer 1

您可以按照 android 文档here 中的说明轻松获取缩略图的位图，但从您的问题来看，您似乎需要完整尺寸的图片位图，因此要获得完整尺寸的位图，您必须将相机对准到可以存储捕获图片的某个文件。

要获得完整大小的位图，试试这个

private String imagePath = "";

private void startCamera() {
    // create a collision-resistant file name
    String fileUniqueName= new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    String imageFileName = fileUniqueName + ".jpg";

    File storageDir = Environment.getExternalStoragePublicDirectory(
        Environment.DIRECTORY_PICTURES);
    imagePath = storageDir.getAbsolutePath() + "/" + imageFileName;
    File file = new File(imagePath);
    Uri outputFileUri = Uri.fromFile(file);

    Intent cameraIntent = new     Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);               
    cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);
    startActivityForResult(cameraIntent, 1);
}

处理捕获的图像

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == 1) {
        File tempFile = new  File(imagePath);
        if(tempFile.exists()){        
            Bitmap requiredBitmap = BitmapFactory.decodeFile(tempFile.getAbsolutePath());
        }
    }
}

此捕获的图像不会显示在图库中。

Answer 2

或者，您可以使用免费的 SDK，无需拍照即可进行 OCR：ABBYY Real-time Recognition SDK。它为您完成了处理视频流的所有工作。

免责声明：我为 ABBYY 工作。

Answer 3

/* this is the code of main activity it will capture text without taking picture all you need to do is to make a text field in mainActivity.xml */
    import android.Manifest;
    import android.content.pm.PackageManager;
    import android.support.annotation.NonNull;
    import android.support.v4.app.ActivityCompat;
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;

> Blockquote

    import android.util.Log;
    import android.util.SparseArray;
    import android.view.SurfaceHolder;
    import android.view.SurfaceView;
    import android.widget.TextView;

    import com.google.android.gms.vision.CameraSource;
    import com.google.android.gms.vision.Detector;
    import com.google.android.gms.vision.text.TextBlock;
    import com.google.android.gms.vision.text.TextRecognizer;

    import java.io.IOException;

    public class MainActivity extends AppCompatActivity {

        SurfaceView cameraView;
        TextView textView;
        CameraSource cameraSource;
        final int RequestCameraPermissionID = 1001;

        @Override
        public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
            switch (requestCode)
            {
                case RequestCameraPermissionID:
                {
                    if(grantResults[0]==PackageManager.PERMISSION_GRANTED)
                    {
                        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
                            return;
                        }
                        try {
                            cameraSource.start(cameraView.getHolder());
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
            }
        }

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

            cameraView = (SurfaceView) findViewById(R.id.surface_view);
            textView = (TextView) findViewById(R.id.text_view);

            TextRecognizer textRecognizer = new TextRecognizer.Builder(getApplicationContext()).build();
            if (!textRecognizer.isOperational()) {
                Log.w("MainActivity", "Detector dependencies are not yet available");
            } else {
                cameraSource = new CameraSource.Builder(getApplicationContext(), textRecognizer)
                        .setFacing(CameraSource.CAMERA_FACING_BACK)
                        .setRequestedPreviewSize(1280, 1024)
                        .setRequestedFps(2.0f)
                        .setAutoFocusEnabled(true)
                        .build();
                cameraView.getHolder().addCallback(new SurfaceHolder.Callback() {
                    @Override
                    public void surfaceCreated(SurfaceHolder holder) {

                        try {
                            if (ActivityCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {

                               ActivityCompat.requestPermissions(MainActivity.this,
                                       new String[]{Manifest.permission.CAMERA},
                                       RequestCameraPermissionID);
                                return;
                            }
                            cameraSource.start(cameraView.getHolder());
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }

                    @Override
                    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

                    }

                    @Override
                    public void surfaceDestroyed(SurfaceHolder holder) {
                        cameraSource.stop();
                    }
                });

                textRecognizer.setProcessor(new Detector.Processor<TextBlock>() {
                    @Override
                    public void release() {

                    }

                    @Override
                    public void receiveDetections(Detector.Detections<TextBlock> detections) {
                        final SparseArray<TextBlock> items = detections.getDetectedItems();
                        if(items.size()!=0){
                            textView.post(new Runnable() {
                                @Override
                                public void run() {
                                    StringBuilder stringBuilder=new StringBuilder();
                                    for(int i=0;i<items.size();i++){
                                        TextBlock item = items.valueAt(i);
                                        stringBuilder.append(item.getValue());
                                        stringBuilder.append("\n");
                                    }
                                    textView.setText(stringBuilder.toString());
                                }
                            });
                        }
                    }
                });
            }
        }
    }