需要使用POS打印机在Android中打印图像

Question

我需要在Android中打印图片。我使用了以下代码。我的问题是如果我用64x64打印图像，图像被分成三个部分并以水平顺序打印。如下，

public class PrinterCommands {
 public static final byte[] INIT = {27, 64};
 public static byte[] FEED_LINE = {10};

 public static byte[] SELECT_FONT_A = {27, 33, 0};

 public static byte[] SET_BAR_CODE_HEIGHT = {29, 104, 100};
 public static byte[] PRINT_BAR_CODE_1 = {29, 107, 2};
 public static byte[] SEND_NULL_BYTE = {0x00};

 public static byte[] SELECT_PRINT_SHEET = {0x1B, 0x63, 0x30, 0x02};
 public static byte[] FEED_PAPER_AND_CUT = {0x1D, 0x56, 66, 0x00};

 public static byte[] SELECT_CYRILLIC_CHARACTER_CODE_TABLE = {0x1B, 0x74, 0x11};

 public static byte[] SELECT_BIT_IMAGE_MODE = {0x1B, 0x2A, 33, 255, 3};
 public static byte[] SET_LINE_SPACING_24 = {0x1B, 0x33, 24};
 public static byte[] SET_LINE_SPACING_30 = {0x1B, 0x33, 30};

 public static byte[] TRANSMIT_DLE_PRINTER_STATUS = {0x10, 0x04, 0x01};
 public static byte[] TRANSMIT_DLE_OFFLINE_PRINTER_STATUS = {0x10, 0x04, 0x02};
 public static byte[] TRANSMIT_DLE_ERROR_STATUS = {0x10, 0x04, 0x03};
 public static byte[] TRANSMIT_DLE_ROLL_PAPER_SENSOR_STATUS = {0x10, 0x04, 0x04};
 }

灰度转换：

 public String convertBitmap(Bitmap inputBitmap) {

 mWidth = inputBitmap.getWidth();
 mHeight = inputBitmap.getHeight();

 convertArgbToGrayscale(inputBitmap, mWidth, mHeight);
 mStatus = "ok";
 return mStatus;
}

private void convertArgbToGrayscale(Bitmap bmpOriginal, int width,
    int height) {
int pixel;
int k = 0;
int B = 0, G = 0, R = 0;
dots = new BitSet();
try {

    for (int x = 0; x < height; x++) {
        for (int y = 0; y < width; y++) {
            // get one pixel color
            pixel = bmpOriginal.getPixel(y, x);

            // retrieve color of all channels
            R = Color.red(pixel);
            G = Color.green(pixel);
            B = Color.blue(pixel);
            // take conversion up to one single value by calculating
            // pixel intensity.
            R = G = B = (int) (0.299 * R + 0.587 * G + 0.114 * B);
            // set bit into bitset, by calculating the pixel's luma
            if (R < 55) {                       
                dots.set(k);//this is the bitset that i'm printing
            }
            k++;
        }
    }

} catch (Exception e) {
    // TODO: handle exception
    Log.e(TAG, e.toString());
}

}

打印图像

 private void print_image(String file) {
   File fl = new File(file);
   if (fl.exists()) {
    Bitmap bmp = BitmapFactory.decodeFile(file);
    convertBitmap(bmp);
    mService.write(PrinterCommands.SET_LINE_SPACING_24);

    int offset = 0;
    while (offset < bmp.getHeight()) {
        mService.write(PrinterCommands.SELECT_BIT_IMAGE_MODE);
        for (int x = 0; x < bmp.getWidth(); ++x) {

            for (int k = 0; k < 3; ++k) {

                byte slice = 0;
                for (int b = 0; b < 8; ++b) {
                    int y = (((offset / 8) + k) * 8) + b;
                    int i = (y * bmp.getWidth()) + x;
                    boolean v = false;
                    if (i < dots.length()) {
                        v = dots.get(i);
                    }
                    slice |= (byte) ((v ? 1 : 0) << (7 - b));
                }
                mService.write(slice);
            }
        }
        offset += 24;
        mService.write(PrinterCommands.FEED_LINE);
        mService.write(PrinterCommands.FEED_LINE);          
        mService.write(PrinterCommands.FEED_LINE);
        mService.write(PrinterCommands.FEED_LINE);
        mService.write(PrinterCommands.FEED_LINE);
        mService.write(PrinterCommands.FEED_LINE);
    }
    mService.write(PrinterCommands.SET_LINE_SPACING_30);


 } else {
    Toast.makeText(this, "file doesn't exists", Toast.LENGTH_SHORT)
            .show();
 }
}