利用Java生成可扩展EPS的QR码

时间:2012-04-27 17:01:01

标签: java qr-code

我目前正在开发一款使用ZXing生成QR码作为图片的应用。这是一个简单的例子:

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.WriterException;
import com.google.zxing.client.j2se.MatrixToImageWriter;
import com.google.zxing.common.BitMatrix;

public class MyQREncoder {

    /**
     * @param args
     * @throws WriterException 
     * @throws IOException 
     * @throws FileNotFoundException 
     */
    public static void main(String[] args) throws WriterException, FileNotFoundException, IOException {
        String text = "Some text to encode";
        int width = 300;
        int height = 300;
        BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE,width,height);
        String file = "plop.png";
        String format = "png";
        MatrixToImageWriter.writeToStream(bitMatrix, format, new FileOutputStream(new File(file)));
    }

}

这会生成一个PNG文件,其中包含可扫描的QRcode,上面写着“要编码的某些文字”。

我的问题是,如果我尝试将格式更改为eps,那么我将获得一个空文件。我们使用的当前解决方案是通过imagemagick转换实用程序将png文件转换为eps。但是给定的EPS只是嵌入原始图像,并且不能很好地扩展(特别是在打印时)。

有人知道是否有任何开源解决方案(使用Zxing或其他)来构建可扩展的Eps文件? (或任何矢量格式)

1 个答案:

答案 0 :(得分:4)

编辑:这是一个完整的Java解决方案:

PrintStream psFile = /* Open file */;

final int blockSize = 4;

psFile.println("%!PS-Adobe-3.0 EPSF-3.0");
psFile.println("%%BoundingBox: 0 0 " + bitMatrix.getWidth() * blockSize + " " + bitMatrix.getHeight() * blockSize);

psFile.print("/bits [");
for(int y = 0; y < bitMatrix.getHeight(); ++y) {
    for(int x = 0; x < bitMatrix.getWidth(); ++x) {
        psFile.print(bitMatrix.get(x, y) ? "1 " : "0 ");
    }           
}
psFile.println("] def");

psFile.println("/width " + bitMatrix.getWidth() + " def");
psFile.println("/height " + bitMatrix.getHeight() + " def");

psFile.println(
        "/y 0 def\n" + 
        blockSize + " " + blockSize + " scale\n" + 
        "height {\n" +
        "   /x 0 def\n" +
        "   width {\n" +
        "      bits y width mul x add get 1 eq {\n" +
        "         newpath\n" +
        "         x y moveto\n" +
        "         0 1 rlineto\n" +
        "         1 0 rlineto\n" +
        "         0 -1 rlineto\n" +
        "         closepath\n" +
        "         fill\n" +
        "      } if\n" +
        "      /x x 1 add def\n" +
        "   } repeat\n" +
        "   /y y 1 add def\n" +
        "} repeat\n");
psFile.close();

如何自己生成PS文件?像这样:

%!PS-Adobe-3.0 EPSF-3.0
%%BoundingBox: 0 0 288 288

/bits [0 0 1 0  1 0 1 1  0 1 1 0  1 1 0 0] def

/width 4 def
/height 4 def
/y 0 def

72 72 scale

height {
   /x 0 def
   width {
      bits y width mul x add get 1 eq {
         newpath
         x y moveto
         0 1 rlineto
         1 0 rlineto
         0 -1 rlineto
         closepath
         fill
      } if
      /x x 1 add def
   } repeat
   /y y 1 add def
} repeat

(当然,你可以在顶部用自己的值填写defs,迭代BitMatrix并打印1和0来填充bitsps file output