从画廊android中的图像扫描条形码答案

【问题标题】：Scan barcode from an image in gallery android从画廊android中的图像扫描条形码
【发布时间】：2015-06-21 09:09:00
【问题描述】：

我正在创建一个android项目，主要功能是扫描条形码。

我尝试将Zxing 库集成到我的项目中，并且工作正常。

但是，它似乎不支持从 android 设备库中的可用图像中扫描条形码。

我该怎么做？或与其他条形码库？

【问题讨论】：

标签： android qr-code barcode-scanner image-gallery

【解决方案1】：

您可以使用 ZXing 库中的此类 MultiFormatReader。

您必须在 BitMap 中获取图库图像并将其转换为：

Bitmap bMap = [...];
String contents = null;

int[] intArray = new int[bMap.getWidth()*bMap.getHeight()];  
//copy pixel data from the Bitmap into the 'intArray' array  
bMap.getPixels(intArray, 0, bMap.getWidth(), 0, 0, bMap.getWidth(), bMap.getHeight());  

LuminanceSource source = new RGBLuminanceSource(bMap.getWidth(), bMap.getHeight(), intArray);
BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));

Reader reader = new MultiFormatReader();
Result result = reader.decode(bitmap);
contents = result.getText();

更新1

要操作大图，请看：

https://developer.android.com/training/articles/memory.html

https://developer.android.com/training/displaying-bitmaps/manage-memory.html

您可以使用此属性android:largeHeap 来增加堆大小。

【讨论】：

@MítTơLớp，有用吗？
对不起，我的回复很慢。我试过你的代码，对于一些图片，它的工作很棒。但是其他一些图片，它在以下位置崩溃： int[] intArray = new int[bitmap.getWidth() * bitmap.getHeight()];原因：java.lang.OutOfMemoryError
我该如何修复这些错误？请。
@MítTơLớp，我觉得有些图片太大了。崩溃时图片的大小是多少？
是的。它是 3264 x 2448。我在 Galaxy s3 上测试过。

【解决方案2】：

我有一个关于如何实现它的工作示例，如果您在 2016 年阅读，我就是这样做的：

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    //initialize variables to make them global
    private ImageButton Scan;
    private static final int SELECT_PHOTO = 100;
  //for easy manipulation of the result
     public String barcode;

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

        //cast neccesary variables to their views
        Scan = (ImageButton)findViewById(R.id.ScanBut);

        //set a new custom listener
        Scan.setOnClickListener(this);
        //launch gallery via intent
        Intent photoPic = new Intent(Intent.ACTION_PICK);
        photoPic.setType("image/*");
        startActivityForResult(photoPic, SELECT_PHOTO);
    }

    //do necessary coding for each ID
    @Override
    public void onClick(View v) {
         switch (v.getId()){
             case R.id.ScanBut:
                 //launch gallery via intent
                 Intent photoPic = new Intent(Intent.ACTION_PICK);
                 photoPic.setType("image/*");
                 startActivityForResult(photoPic, SELECT_PHOTO);
                       break;
         }
    }

//call the onactivity result method
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent imageReturnedIntent) {
        super.onActivityResult(requestCode, resultCode, imageReturnedIntent);
        switch (requestCode) {
            case SELECT_PHOTO:
                if (resultCode == RESULT_OK) {
//doing some uri parsing
                    Uri selectedImage = imageReturnedIntent.getData();
                    InputStream imageStream = null;
                    try {
                        //getting the image
                        imageStream = getContentResolver().openInputStream(selectedImage);
                    } catch (FileNotFoundException e) {
                        Toast.makeText(getApplicationContext(), "File not found", Toast.LENGTH_SHORT).show();
                        e.printStackTrace();
                    }
                    //decoding bitmap
                    Bitmap bMap = BitmapFactory.decodeStream(imageStream);
                    Scan.setImageURI(selectedImage);// To display selected image in image view
                    int[] intArray = new int[bMap.getWidth() * bMap.getHeight()];
                    // copy pixel data from the Bitmap into the 'intArray' array
                    bMap.getPixels(intArray, 0, bMap.getWidth(), 0, 0, bMap.getWidth(),
                            bMap.getHeight());

                    LuminanceSource source = new RGBLuminanceSource(bMap.getWidth(),
                            bMap.getHeight(), intArray);
                    BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));

                    Reader reader = new MultiFormatReader();// use this otherwise
                    // ChecksumException
                    try {
                        Hashtable<DecodeHintType, Object> decodeHints = new Hashtable<DecodeHintType, Object>();
                        decodeHints.put(DecodeHintType.TRY_HARDER, Boolean.TRUE);
                        decodeHints.put(DecodeHintType.PURE_BARCODE, Boolean.TRUE);

                        Result result = reader.decode(bitmap, decodeHints);
         //*I have created a global string variable by the name of barcode to easily manipulate data across the application*//
                        barcode =  result.getText().toString();

                           //do something with the results for demo i created a popup dialog
                        if(barcode!=null){
                            AlertDialog.Builder builder = new AlertDialog.Builder(this);
                            builder.setTitle("Scan Result");
                            builder.setIcon(R.mipmap.ic_launcher);
                            builder.setMessage("" + barcode);
                            AlertDialog alert1 = builder.create();
                            alert1.setButton(DialogInterface.BUTTON_POSITIVE, "Done", new DialogInterface.OnClickListener() {
                                @Override
                                public void onClick(DialogInterface dialog, int which) {
                                    Intent i = new Intent (getBaseContext(),MainActivity.class);
                                    startActivity(i);
                                }
                            });

                            alert1.setCanceledOnTouchOutside(false);

                            alert1.show();}
                        else
                        {
                            AlertDialog.Builder builder = new AlertDialog.Builder(this);
                            builder.setTitle("Scan Result");
                            builder.setIcon(R.mipmap.ic_launcher);
                            builder.setMessage("Nothing found try a different image or try again");
                            AlertDialog alert1 = builder.create();
                            alert1.setButton(DialogInterface.BUTTON_POSITIVE, "Done", new DialogInterface.OnClickListener() {
                                @Override
                                public void onClick(DialogInterface dialog, int which) {
                                    Intent i = new Intent (getBaseContext(),MainActivity.class);
                                    startActivity(i);
                                }
                            });

                            alert1.setCanceledOnTouchOutside(false);

                            alert1.show();

                        }
                     //the end of do something with the button statement.

                    } catch (NotFoundException e) {
                        Toast.makeText(getApplicationContext(), "Nothing Found", Toast.LENGTH_SHORT).show();
                        e.printStackTrace();
                    } catch (ChecksumException e) {
                        Toast.makeText(getApplicationContext(), "Something weird happen, i was probably tired to solve this issue", Toast.LENGTH_SHORT).show();
                        e.printStackTrace();
                    } catch (FormatException e) {
                        Toast.makeText(getApplicationContext(), "Wrong Barcode/QR format", Toast.LENGTH_SHORT).show();
                        e.printStackTrace();
                    } catch (NullPointerException e) {
                        Toast.makeText(getApplicationContext(), "Something weird happen, i was probably tired to solve this issue", Toast.LENGTH_SHORT).show();
                        e.printStackTrace();
                    }
                }
        }
    }

}

【讨论】：

添加如何此代码回答问题将有助于未来的访问者。
@LucienMendela 谢谢。它工作..但它只扫描黑白png..如何扫描不同颜色的qr？
而且问题是相同的，它适用于大多数图像，但不适用于相同。为了验证生成的 QR 图像是否正确，我使用 在线工具 (qrlogo.kaarposoft.dk/qrdecode.html) 进行了检查，它能够成功解码。我有强烈的感觉，Zxing 在移动 SDK 方面缺少一些东西。

【解决方案3】：

我处于同一场景之间，它抛出 NotFoundException，official doc 说

在图像中未找到条形码时抛出。可能是部分检测到但无法确认。

一级解决方案 在某种程度上，@Laurent 答案几乎适用于我拥有的每个样本，但很少失败。

下一级解决方案在@Lucien Mendela 建议的 reader.decode(..) 之前添加 decodeHints 就可以了。

Hashtable<DecodeHintType, Object> decodeHints = new Hashtable<DecodeHintType, Object>();
decodeHints.put(DecodeHintType.TRY_HARDER, Boolean.TRUE); // Not required in my case
decodeHints.put(DecodeHintType.PURE_BARCODE, Boolean.TRUE);

但最后的事情对我有用

如果您的图片很大，您可能需要缩小尺寸。
它还需要一个 ~rectangle 形状（在我的例子中是 421*402）。

参考添加几个类似的问题：

Random com.google.zxing.NotFoundException during the reading valid QRCode

您可以用来验证您拥有的图像的工具：

qrdecode（别忘了勾选“生成调试输出”以获取调试信息）
Zxing Decoder online

【讨论】：

【解决方案4】：

首先，当然，从图库中读取图片（这可以在您的活动中）： Help by

Intent pickIntent = new Intent(Intent.ACTION_PICK);
    pickIntent.setDataAndType( android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI, "image/*");

    startActivityForResult(pickIntent, 111);

之后，只需获取活动结果上的图像 uri，ZXing 就会发挥作用：

 @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        switch (requestCode) {
            //the case is because you might be handling multiple request codes here
            case 111:
                if(data == null || data.getData()==null) {
                    Log.e("TAG", "The uri is null, probably the user cancelled the image selection process using the back button.");
                    return;
                }
                Uri uri = data.getData();
                try
                {
                    InputStream inputStream = getContentResolver().openInputStream(uri);
                    Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
                    if (bitmap == null)
                    {
                        Log.e("TAG", "uri is not a bitmap," + uri.toString());
                        return;
                    }
                    int width = bitmap.getWidth(), height = bitmap.getHeight();
                    int[] pixels = new int[width * height];
                    bitmap.getPixels(pixels, 0, width, 0, 0, width, height);
                    bitmap.recycle();
                    bitmap = null;
                    RGBLuminanceSource source = new RGBLuminanceSource(width, height, pixels);
                    BinaryBitmap bBitmap = new BinaryBitmap(new HybridBinarizer(source));
                    MultiFormatReader reader = new MultiFormatReader();
                    try
                    {
                        Result result = reader.decode(bBitmap);
                        Toast.makeText(this, "The content of the QR image is: " + result.getText(), Toast.LENGTH_SHORT).show();
                    }
                    catch (NotFoundException e)
                    {
                        Log.e("TAG", "decode exception", e);
                    }
                }
                catch (FileNotFoundException e)
                {
                    Log.e("TAG", "can not open file" + uri.toString(), e);
                }
                break;
        }
    }

【讨论】：