android图片文字识别demo（基于百度ocr）

 /**
     * 通过图片URL的形式，获取图片内的文字信息
     * @param accessToken 通过API Key和Secret Key获取的access_token
     * @param url 图片的url
     * @return observable对象用于rxjava,从RecognitionResultBean中可以获得图片文字识别的信息
     */
    @POST("rest/2.0/ocr/v1/general_basic")
    @FormUrlEncoded
    Observable<RecognitionResultBean> getRecognitionResultByUrl(@Field("access_token") String accessToken, @Field("url") String url);

    /**
     * 通过图片，获取图片内的文字信息
     * @param accessToken 通过API Key和Secret Key获取的access_token
     * @param image 图像数据base64编码后进行urlencode后的String
     * @return  observable对象用于rxjava,从RecognitionResultBean中可以获得图片文字识别的信息
     */
    @POST("rest/2.0/ocr/v1/general_basic")
    @FormUrlEncoded
    Observable<RecognitionResultBean> getRecognitionResultByImage(@Field("access_token") String accessToken, @Field("image") String image);

 Retrofit retrofit = new Retrofit.Builder()
                .baseUrl("https://aip.baidubce.com/")
                .addConverterFactory(GsonConverterFactory.create())
                .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
                .build();

        baiduOCRService = retrofit.create(BaiduOCRService.class);

  @Override
    public void getRecognitionResultByImage(Bitmap bitmap) 

        String encodeResult = bitmapToString(bitmap);

        baiduOCRService.getRecognitionResultByImage(ACCESS_TOKEN,encodeResult)
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(new Observer<RecognitionResultBean>() 
                    @Override
                    public void onSubscribe(Disposable d) 

                    

                    @Override
                    public void onNext(RecognitionResultBean recognitionResultBean) 
                        Log.e("onnext",recognitionResultBean.toString());
                        StringBuilder s = new StringBuilder();
                        List<RecognitionResultBean.WordsResultBean> wordsResult = recognitionResultBean.getWords_result();
                        for (RecognitionResultBean.WordsResultBean words:wordsResult) 
                            s.append(words.getWords());
                        

                        mView.updateUI(s.toString());

                    

                    @Override
                    public void onError(Throwable e) 
                        Log.e("onerror",e.toString());
                    

                    @Override
                    public void onComplete() 

                    
                );

    

    private String bitmapToString(Bitmap bitmap)
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);
        byte[] bytes = baos.toByteArray();
        return Base64.encodeToString(bytes, Base64.DEFAULT);
    

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

    private boolean hasPermission() 
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED
                || ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED
                || ContextCompat.checkSelfPermission(this,Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) 
            ActivityCompat.requestPermissions(this, new String[]Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.CAMERA, PERMISSIONS_REQUEST_CODE);
            return false;
        else 
            return true;
        
    

 private void takePhoto()

        if (!hasPermission()) 
            return;
        

        Intent intent = new Intent();
        intent.setAction(MediaStore.ACTION_IMAGE_CAPTURE);
        String path = Environment.getExternalStorageDirectory().getAbsolutePath() + "/img";
        if (new File(path).exists()) 
            try 
                new File(path).createNewFile();
             catch (IOException e) 
                e.printStackTrace();
            
        
        String filename = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        mTmpFile = new File(path, filename + ".jpg");
        mTmpFile.getParentFile().mkdirs();

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) 
            String authority = getPackageName() + ".provider";
            imageUri = FileProvider.getUriForFile(this, authority, mTmpFile);
         else 
            imageUri = Uri.fromFile(mTmpFile);
        
        intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);

        startActivityForResult(intent, CAMERA_REQUEST_CODE);

    

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) 
        if (requestCode == CAMERA_REQUEST_CODE) 
            if (requestCode == RESULT_OK)
                Bitmap photo = BitmapFactory.decodeFile(mTmpFile.getAbsolutePath());
                mPresenter.getRecognitionResultByImage(photo);
                imageView.setImageBitmap(photo);