1 ZXing解析二维码
上一篇文件已经说过如何用ZXing进行生成二维码和带图片的二维码，下面说下如何解析二维码
二维码的解析和生成类似，也可以参考google的一个操作类 BufferedImageLuminanceSource类，该类可在google的测试包中找到，另外j2se中也有该类，你可以将该类直接拷贝到源码中使用，你也可以自己写个。
1.1 BufferedImageLuminanceSource类
package t1;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.awt.image.WritableRaster;
import com.google.zxing.LuminanceSource;
/**
*
* 二维码的解析需要借助BufferedImageLuminanceSource类，该类是由Google提供的，可以将该类直接拷贝到源码中使用，当然你也可以自己写个
* 解析条形码的基类
*/
public final class BufferedImageLuminanceSource extends LuminanceSource {
private static final double MINUS_45_IN_RADIANS = -0.7853981633974483; // Math.toRadians(-45.0)
private final BufferedImage image;
private final int left;
private final int top;
private static final boolean EXPLICIT_LUMINANCE_CONVERSION;
static {
String property = System.getProperty("explicitLuminanceConversion");
if (property == null) {
property = System.getenv("EXPLICIT_LUMINANCE_CONVERSION");
}
EXPLICIT_LUMINANCE_CONVERSION = Boolean.parseBoolean(property);
}
public BufferedImageLuminanceSource(BufferedImage image) {
this(image, 0, 0, image.getWidth(), image.getHeight());
}
public BufferedImageLuminanceSource(BufferedImage image, int left, int top, int width, int height) {
super(width, height);
if (image.getType() == BufferedImage.TYPE_BYTE_GRAY) {
this.image = image;
} else {
int sourceWidth = image.getWidth();
int sourceHeight = image.getHeight();
if (left + width > sourceWidth || top + height > sourceHeight) {
throw new IllegalArgumentException("Crop rectangle does not fit within image data.");
}
this.image = new BufferedImage(sourceWidth, sourceHeight, BufferedImage.TYPE_BYTE_GRAY);
if (EXPLICIT_LUMINANCE_CONVERSION) {
WritableRaster raster = this.image.getRaster();
int[] buffer = new int[width];
for (int y = top; y < top + height; y++) {
image.getRGB(left, y, width, 1, buffer, 0, sourceWidth);
for (int x = 0; x < width; x++) {
int pixel = buffer[x];
// see comments in implicit branch
if ((pixel & 0xFF000000) == 0) {
pixel = 0xFFFFFFFF; // = white
}
// .229R + 0.587G + 0.114B (YUV/YIQ for PAL and NTSC)
buffer[x] =
(306 * ((pixel >> 16) & 0xFF) +
601 * ((pixel >> 8) & 0xFF) +
117 * (pixel & 0xFF) +
0x200) >> 10;
}
raster.setPixels(left, y, width, 1, buffer);
}
} else {
// The color of fully-transparent pixels is irrelevant. They are often, technically, fully-transparent
// black (0 alpha, and then 0 RGB). They are often used, of course as the "white" area in a
// barcode image. Force any such pixel to be white:
if (image.getAlphaRaster() != null) {
int[] buffer = new int[width];
for (int y = top; y < top + height; y++) {
image.getRGB(left, y, width, 1, buffer, 0, sourceWidth);
boolean rowChanged = false;
for (int x = 0; x < width; x++) {
if ((buffer[x] & 0xFF000000) == 0) {
buffer[x] = 0xFFFFFFFF; // = white
rowChanged = true;
}
}
if (rowChanged) {
image.setRGB(left, y, width, 1, buffer, 0, sourceWidth);
}
}
}
// Create a grayscale copy, no need to calculate the luminance manually
this.image.getGraphics().drawImage(image, 0, 0, null);
}
}
this.left = left;
this.top = top;
}
@Override
public byte[] getRow(int y, byte[] row) {
if (y < 0 || y >= getHeight()) {
throw new IllegalArgumentException("Requested row is outside the image: " + y);
}
int width = getWidth();
if (row == null || row.length < width) {
row = new byte[width];
}
// The underlying raster of image consists of bytes with the luminance values
image.getRaster().getDataElements(left, top + y, width, 1, row);
return row;
}
@Override
public byte[] getMatrix() {
int width = getWidth();
int height = getHeight();
int area = width * height;
byte[] matrix = new byte[area];
// The underlying raster of image consists of area bytes with the luminance values
image.getRaster().getDataElements(left, top, width, height, matrix);
return matrix;
}
@Override
public boolean isCropSupported() {
return true;
}
@Override
public LuminanceSource crop(int left, int top, int width, int height) {
return new BufferedImageLuminanceSource(image, this.left + left, this.top + top, width, height);
}
/**
* This is always true, since the image is a gray-scale image.
*
* @return true
*/
@Override
public boolean isRotateSupported() {
return true;
}
@Override
public LuminanceSource rotateCounterClockwise() {
int sourceWidth = image.getWidth();
int sourceHeight = image.getHeight();
// Rotate 90 degrees counterclockwise.
AffineTransform transform = new AffineTransform(0.0, -1.0, 1.0, 0.0, 0.0, sourceWidth);
// Note width/height are flipped since we are rotating 90 degrees.
BufferedImage rotatedImage = new BufferedImage(sourceHeight, sourceWidth, BufferedImage.TYPE_BYTE_GRAY);
// Draw the original image into rotated, via transformation
Graphics2D g = rotatedImage.createGraphics();
g.drawImage(image, transform, null);
g.dispose();
// Maintain the cropped region, but rotate it too.
int width = getWidth();
return new BufferedImageLuminanceSource(rotatedImage, top, sourceWidth - (left + width), getHeight(), width);
}
@Override
public LuminanceSource rotateCounterClockwise45() {
int width = getWidth();
int height = getHeight();
int oldCenterX = left + width / 2;
int oldCenterY = top + height / 2;
// Rotate 45 degrees counterclockwise.
AffineTransform transform = AffineTransform.getRotateInstance(MINUS_45_IN_RADIANS, oldCenterX, oldCenterY);
int sourceDimension = Math.max(image.getWidth(), image.getHeight());
BufferedImage rotatedImage = new BufferedImage(sourceDimension, sourceDimension, BufferedImage.TYPE_BYTE_GRAY);
// Draw the original image into rotated, via transformation
Graphics2D g = rotatedImage.createGraphics();
g.drawImage(image, transform, null);
g.dispose();
int halfDimension = Math.max(width, height) / 2;
int newLeft = Math.max(0, oldCenterX - halfDimension);
int newTop = Math.max(0, oldCenterY - halfDimension);
int newRight = Math.min(sourceDimension - 1, oldCenterX + halfDimension);
int newBottom = Math.min(sourceDimension - 1, oldCenterY + halfDimension);
return new BufferedImageLuminanceSource(rotatedImage, newLeft, newTop, newRight - newLeft, newBottom - newTop);
}
}
1.2 操作类：DecodeTest
package t1;
import java.awt.image.BufferedImage;
import java.io.File;
import java.util.Hashtable;
import javax.imageio.ImageIO;
import com.google.zxing.Binarizer;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.DecodeHintType;
import com.google.zxing.LuminanceSource;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.Result;
import com.google.zxing.common.HybridBinarizer;
/**
* 解析二维码
* @author Administrator
*
*/
public class DecodeHelper {
public static void main(String[] args) throws Exception {
try {
MultiFormatReader formatReader = new MultiFormatReader();
String filePath = "e:\\new-1.gif"; //new.png
File file = new File(filePath);
BufferedImage image = ImageIO.read(file);
LuminanceSource source = new BufferedImageLuminanceSource(image);
Binarizer binarizer = new HybridBinarizer(source);
BinaryBitmap binaryBitmap = new BinaryBitmap(binarizer);
Hashtable<DecodeHintType, Object> hints = new Hashtable<DecodeHintType, Object>();
hints.put(DecodeHintType.CHARACTER_SET, "UTF-8");
Result result = formatReader.decode(binaryBitmap,hints);
System.out.println("result = "+ result.toString());
System.out.println("resultFormat = "+ result.getBarcodeFormat());
System.out.println("resultText = "+ result.getText());
} catch (Exception e) {
e.printStackTrace();
}
}
}
1.3 补充
a.读取二维码图片，并送给 Zxing LuminanceSource 和 Binarizer 两兄弟的处理。
b.处理完的位图和相应的解析参数，交由 MultiFormatReader 处理，并返回解析后的结果。
c.如果对上述 两兄弟的处理 和 MultiFormatReader 的解析有兴趣，可以读读源码。
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时间： 2024-07-29 00:06:17