JAVA識別圖形驗證碼

jopen 11年前發布 | 88K 次閱讀驗證碼驗證碼(Captcha)
用HttpClient模擬客戶端瀏覽器注冊發帖。但是碰到了圖形驗證碼的問題了，對單數字的驗證碼，通過一些OCR引擎，如：tesseract，AspriseOCR很容易解決問題。但碰到如CSDN論壇這中圖形驗證碼就比較麻煩，必須先通過預處理。使圖象二值化，黑白灰度，增加亮度。
package myfilter;
import java.io.;
import java.awt.image.;
import java.awt.geom.AffineTransform;
import java.awt.color.ColorSpace;
import java.awt.image.ConvolveOp;
import java.awt.image.Kernel;
import java.awt.image.BufferedImage;
import javax.imageio.ImageIO;
import java.awt.Toolkit;
import java.awt.Image;
public class MyImgFilter {
BufferedImage image;
private int iw, ih;
private int[] pixels;
public MyImgFilter(BufferedImage image) {
this.image = image;
iw = image.getWidth();
ih = image.getHeight();
pixels = new int[iw  ih];
}
public BufferedImage changeGrey() {
PixelGrabber pg = new PixelGrabber(image.getSource(), 0, 0, iw, ih, pixels,0, iw);
try {
pg.grabPixels();
} catch (InterruptedException e) {
e.printStackTrace();
}
// 設定二值化的域值，默認值為100
int grey = 100;
// 對圖像進行二值化處理，Alpha值保持不變
ColorModel cm = ColorModel.getRGBdefault();
for (int i = 0; i < iw  ih; i++) {
int red, green, blue;
int alpha = cm.getAlpha(pixels[i]);
if (cm.getRed(pixels[i]) > grey) {
red = 255;
} else {
red = 0;
}
if (cm.getGreen(pixels[i]) > grey) {
green = 255;
} else {
green = 0;
}
if (cm.getBlue(pixels[i]) > grey) {
blue = 255;
} else {
blue = 0;
}
pixels[i] = alpha << 24 | red << 16 | green << 8 | blue; //通過移位重新構成某一點像素的RGB值
}
// 將數組中的象素產生一個圖像
Image tempImg=Toolkit.getDefaultToolkit().createImage(new MemoryImageSource(iw,ih, pixels, 0, iw));
image = new BufferedImage(tempImg.getWidth(null),tempImg.getHeight(null), BufferedImage.TYPE_INT_BGR );
image.createGraphics().drawImage(tempImg, 0, 0, null);
return image;
}
public BufferedImage getMedian() {
PixelGrabber pg = new PixelGrabber(image.getSource(), 0, 0, iw, ih,
pixels,
0, iw);
try {
pg.grabPixels();
} catch (InterruptedException e) {
e.printStackTrace();
}
// 對圖像進行中值濾波，Alpha值保持不變
ColorModel cm = ColorModel.getRGBdefault();
for (int i = 1; i < ih - 1; i++) {
for (int j = 1; j < iw - 1; j++) {
int red, green, blue;
int alpha = cm.getAlpha(pixels[i  iw + j]);
// int red2 = cm.getRed(pixels[(i - 1)  iw + j]);
int red4 = cm.getRed(pixels[i  iw + j - 1]);
int red5 = cm.getRed(pixels[i  iw + j]);
int red6 = cm.getRed(pixels[i  iw + j + 1]);
// int red8 = cm.getRed(pixels[(i + 1)  iw + j]);
// 水平方向進行中值濾波
if (red4 >= red5) {
if (red5 >= red6) {
red = red5;
} else {
if (red4 >= red6) {
red = red6;
} else {
red = red4;
}
}
} else {
if (red4 > red6) {
red = red4;
} else {
if (red5 > red6) {
red = red6;
} else {
red = red5;
}
}
}
int green4 = cm.getGreen(pixels[i  iw + j - 1]);
int green5 = cm.getGreen(pixels[i  iw + j]);
int green6 = cm.getGreen(pixels[i  iw + j + 1]);
// 水平方向進行中值濾波
if (green4 >= green5) {
if (green5 >= green6) {
green = green5;
} else {
if (green4 >= green6) {
green = green6;
} else {
green = green4;
}
}
} else {
if (green4 > green6) {
green = green4;
} else {
if (green5 > green6) {
green = green6;
} else {
green = green5;
}
}
}
// int blue2 = cm.getBlue(pixels[(i - 1)  iw + j]);
int blue4 = cm.getBlue(pixels[i  iw + j - 1]);
int blue5 = cm.getBlue(pixels[i  iw + j]);
int blue6 = cm.getBlue(pixels[i  iw + j + 1]);
// int blue8 = cm.getBlue(pixels[(i + 1)  iw + j]);
// 水平方向進行中值濾波
if (blue4 >= blue5) {
if (blue5 >= blue6) {
blue = blue5;
} else {
if (blue4 >= blue6) {
blue = blue6;
} else {
blue = blue4;
}
}
} else {
if (blue4 > blue6) {
blue = blue4;
} else {
if (blue5 > blue6) {
blue = blue6;
} else {
blue = blue5;
}
}
}
pixels[i * iw +
j] = alpha << 24 | red << 16 | green << 8 | blue;
}
}
// 將數組中的象素產生一個圖像
Image tempImg=Toolkit.getDefaultToolkit().createImage(new MemoryImageSource(iw,ih, pixels, 0, iw));
image = new BufferedImage(tempImg.getWidth(null),tempImg.getHeight(null), BufferedImage.TYPE_INT_BGR );
image.createGraphics().drawImage(tempImg, 0, 0, null);
return image;
}
public BufferedImage getGrey() {
ColorConvertOp ccp=new ColorConvertOp(ColorSpace.getInstance(ColorSpace.CS_GRAY), null);
return image=ccp.filter(image,null);
}
//Brighten using a linear formula that increases all color values
public BufferedImage getBrighten() {
RescaleOp rop=new RescaleOp(1.25f, 0, null);
return image=rop.filter(image,null);
}
//Blur by "convolving" the image with a matrix
public BufferedImage getBlur() {
float[] data = {
.1111f, .1111f, .1111f,
.1111f, .1111f, .1111f,
.1111f, .1111f, .1111f, };
ConvolveOp cop = new ConvolveOp(new Kernel(3, 3, data));
return image=cop.filter(image,null);
}
// Sharpen by using a different matrix
public BufferedImage getSharpen() {
float[] data = {
0.0f, -0.75f, 0.0f,
-0.75f, 4.0f, -0.75f,
0.0f, -0.75f, 0.0f};
ConvolveOp cop = new ConvolveOp(new Kernel(3, 3, data));
return image=cop.filter(image,null);
}
// 11) Rotate the image 180 degrees about its center point
public BufferedImage getRotate() {
AffineTransformOp atop=new AffineTransformOp(AffineTransform.getRotateInstance(Math.PI,image.getWidth()/2,image.getHeight()/2),
AffineTransformOp.TYPE_NEAREST_NEIGHBOR);
return image=atop.filter(image,null);
}
public BufferedImage getProcessedImg()
{
return image;
}
public static void main(String[] args) throws IOException {
FileInputStream fin=new FileInputStream(args[0]);
BufferedImage bi=ImageIO.read(fin);
MyImgFilter flt=new MyImgFilter(bi);
flt.changeGrey();
flt.getGrey();
flt.getBrighten();
bi=flt.getProcessedImg();
String pname=args[0].substring(0,args[0].lastIndexOf("."));
File file = new File(pname+".jpg");
ImageIO.write(bi, "jpg", file);
}
}
運行java myfilter.MyImgFilter t6.bmp，請確認圖片t6.bmp與myfilter目錄在同一目錄下。
順便說一下，在JDK1.5下，ImageIO可以輸出JPG，BMP，PNG三種格式圖片，但不支持GIF圖片輸出。</pre>
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驗證碼驗證碼(Captcha)
JAVA識別圖形驗證碼

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