textRecognizer.detect(frame);它返回大小为0

时间:2018-10-17 06:07:50

标签: java android bitmap google-vision

我正在使用Google视觉API,并尝试从捕获的图像中获取文本。 我已经在图像视图中设置了捕获的图像,然后尝试从图像中获取文本。但是我得到的大小为0的SparseArray。这可能是问题所在。这是我的Java代码。

    public class MainActivity extends AppCompatActivity {


    ImageView imgPic;
    TextView tvText;
    Button btnClick, btnCapture;
    private int REQUEST_IMAGE_CAPTURE = 1;

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

        imgPic = findViewById(R.id.img_pic);
        tvText = findViewById(R.id.tv_text);
        btnClick = findViewById(R.id.btn_click);
        btnCapture = findViewById(R.id.btn_capture);

        btnCapture.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
                    startActivityForResult(takePictureIntent, REQUEST_IMAGE_CAPTURE);
                }


            }
        });


        btnClick.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

Bitmap bitmap;
 if (imgPic.getDrawable() != null && imgPic.getDrawable() instanceof BitmapDrawable) {
                bitmap = ((BitmapDrawable) imgPic.getDrawable()).getBitmap();
            }

                TextRecognizer textRecognizer = new TextRecognizer.Builder(getApplicationContext()).build();
                if (!textRecognizer.isOperational()) {

                    Toast.makeText(MainActivity.this, "could not get the text", Toast.LENGTH_SHORT).show();
                } else {
                    if (bitmap != null) {
                        Frame frame = new Frame.Builder().setBitmap(bitmap).build();
                        SparseArray<TextBlock> items = textRecognizer.detect(frame);
                        StringBuilder sb = new StringBuilder();
                        for (int i = 0; i < items.size(); i++) {
                            TextBlock myItem = items.valueAt(i);
                            Log.e("hello", (String) myItem.getValue());
                            sb.append(myItem.getValue());
                            sb.append("\n");

                        }

                        tvText.setText(sb.toString());
                    } else {
                        Toast.makeText(MainActivity.this, "returned null", Toast.LENGTH_SHORT).show();

                    }

                }
            }
        });


    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK) {
            Bundle extras = data.getExtras();
            Bitmap imageBitmap = (Bitmap) extras.get("data");
            imgPic.setImageBitmap(imageBitmap);


        }

    }
}

这是我的主要活动xml文件。

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">
    <Button
        android:id="@+id/btn_capture"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:text="capture"
        />


    <ImageView
        android:id="@+id/img_pic"
        android:layout_width="370dp"
        android:layout_height="300dp" />

    <TextView
        android:textColor="@color/colorAccent"
        android:id="@+id/tv_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        android:textSize="25sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="click here"
        android:id="@+id/btn_click"/>
</LinearLayout>

最主要的是,当我在imageView中手动设置图像时,它会显示结果,但是当我自己捕获图像时,我尝试获取文本却没有得到结果,我总是得到一个0大小的数组

1 个答案:

答案 0 :(得分:0)

为什么不将位图存储在全局变量中?您当然可以将ImageView的可绘制对象转换回位图,但这需要额外的资源。

无论如何,您的问题的答案将是:

if(imgPic.getDrawable() != null && imgPic.getDrawable() instanceof BitmapDrawable) {
    Bitmap bitmap = ((BitmapDrawable)imgPic.getDrawable()).getBitmap();
}

您应该检查可绘制对象是否不为null,以及可绘制对象内部存储的位图是否确实为BitmapDrawable类型。