How to generate an Barcode and convert it to Bitma

问题:

How to generate an Barcode and convert it to Bitmap using new Google Vision API?

Barcode barcode = new Barcode();
Barcode.Email email = new Barcode.Email();
email.address = "[e-mail]";
email.subject = "My Subject;
email.body = "My body content.";
barcode.email = email;

//Implement conversion Bitmap barcodeImage = barcodeToBitmap(barcode);// I do know this part.

回答1:

You can detect your barcodes using Google Vision API and then use ZXing to generate the barcodes. You could try something like this, it uses zxing library:

public static Bitmap getBitmap(String barcode, int barcodeType, int width, int height)
{
    Bitmap barcodeBitmap = null;
    BarcodeFormat barcodeFormat = convertToZXingFormat(barcodeType);
    try
    {
        barcodeBitmap = encodeAsBitmap(barcode, barcodeFormat, width, height);
    }
    catch (WriterException e)
    {
        e.printStackTrace();
    }
    return barcodeBitmap;
}

private static BarcodeFormat convertToZXingFormat(int format)
{
    switch (format)
    {
        case 8:
            return BarcodeFormat.CODABAR;
        case 1:
            return BarcodeFormat.CODE_128;
        case 2:
            return BarcodeFormat.CODE_39;
        case 4:
            return BarcodeFormat.CODE_93;
        case 32:
            return BarcodeFormat.EAN_13;
        case 64:
            return BarcodeFormat.EAN_8;
        case 128:
            return BarcodeFormat.ITF;
        case 512:
            return BarcodeFormat.UPC_A;
        case 1024:
            return BarcodeFormat.UPC_E;
        //default 128?
        default:
            return BarcodeFormat.CODE_128;
    }
}


/**************************************************************
 * getting from com.google.zxing.client.android.encode.QRCodeEncoder
 *
 * See the sites below
 * http://code.google.com/p/zxing/
 * http://code.google.com/p/zxing/source/browse/trunk/android/src/com/google/zxing/client/android/encode/EncodeActivity.java
 * http://code.google.com/p/zxing/source/browse/trunk/android/src/com/google/zxing/client/android/encode/QRCodeEncoder.java
 */

private static final int WHITE = 0xFFFFFFFF;
private static final int BLACK = 0xFF000000;

private static Bitmap encodeAsBitmap(String contents, BarcodeFormat format, int img_width, int img_height) throws WriterException
{
    if (contents == null) {
        return null;
    }
    Map<EncodeHintType, Object> hints = null;
    String encoding = guessAppropriateEncoding(contents);
    if (encoding != null) {
        hints = new EnumMap<>(EncodeHintType.class);
        hints.put(EncodeHintType.CHARACTER_SET, encoding);
    }
    MultiFormatWriter writer = new MultiFormatWriter();
    BitMatrix result;
    try {
        result = writer.encode(contents, format, img_width, img_height, hints);
    } catch (IllegalArgumentException iae) {
        // Unsupported format
        return null;
    }
    int width = result.getWidth();
    int height = result.getHeight();
    int[] pixels = new int[width * height];
    for (int y = 0; y < height; y++) {
        int offset = y * width;
        for (int x = 0; x < width; x++) {
            pixels[offset + x] = result.get(x, y) ? BLACK : WHITE;
        }
    }

    Bitmap bitmap = Bitmap.createBitmap(width, height,
            Bitmap.Config.ARGB_8888);
    bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
    return bitmap;
}

private static String guessAppropriateEncoding(CharSequence contents) {
    // Very crude at the moment
    for (int i = 0; i < contents.length(); i++) {
        if (contents.charAt(i) > 0xFF) {
            return "UTF-8";
        }
    }
    return null;
}

}