java 解析图片校验码 java验证码图片辨别

(本文仅用于学习研究图像匹配识别原理，不得用于其他用途。)

最近看了看验证码的识别，先从最简单的做起吧(固定大小，固定位置，固定字体)

 

验证码识别基本分四步，图片预处理，分割，训练，识别

 

看一个最简单验证码

这是一个德克萨斯扑克的注册页面的验证码

 

1。图像的预处理

这种直接根据亮度设个阈值处理就可以了

public static int isWhite(int colorInt) {
		Color color = new Color(colorInt);
		if (color.getRed() + color.getGreen() + color.getBlue() > 100) {
			return 1;
		}
		return 0;
	}

	public static BufferedImage removeBackgroud(String picFile)
			throws Exception {
		BufferedImage img = ImageIO.read(new File(picFile));
		int width = img.getWidth();
		int height = img.getHeight();
		for (int x = 0; x < width; ++x) {
			for (int y = 0; y < height; ++y) {
				if (isWhite(img.getRGB(x, y)) == 1) {
					img.setRGB(x, y, Color.WHITE.getRGB());
				} else {
					img.setRGB(x, y, Color.BLACK.getRGB());
				}
			}
		}
		return img;
	}

 

处理完图片效果为

图像基本分得比较清楚，图片分割也比较容易

 

2。分割

这个验证码居然是固定位置的，分割相当简单，直接截取相应位置就可以了

public static List<BufferedImage> splitImage(BufferedImage img)
			throws Exception {
		List<BufferedImage> subImgs = new ArrayList<BufferedImage>();
		subImgs.add(img.getSubimage(10, 6, 8, 10));
		subImgs.add(img.getSubimage(19, 6, 8, 10));
		subImgs.add(img.getSubimage(28, 6, 8, 10));
		subImgs.add(img.getSubimage(37, 6, 8, 10));
		return subImgs;
	}

3。训练

直接拿几张图片，包含0-9，每个数字一个样本就可以了，将文件名对应相应的数字

4。识别

因为是固定大小，固定位置，识别也很简单。

直接拿分割的图片跟这个十个图片一个像素一个像素的比，相同的点最多的就是结果。比如如果跟5.jpg最相似，那么识别的结果就是5。

下面是识别结果，很容易达到100%

 

 

完整代码(csdn连个附件都不支持)：

import java.awt.Color;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.imageio.ImageIO;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.io.IOUtils;

public class ImagePreProcess {

	public static int isWhite(int colorInt) {
		Color color = new Color(colorInt);
		if (color.getRed() + color.getGreen() + color.getBlue() > 100) {
			return 1;
		}
		return 0;
	}

	public static int isBlack(int colorInt) {
		Color color = new Color(colorInt);
		if (color.getRed() + color.getGreen() + color.getBlue() <= 100) {
			return 1;
		}
		return 0;
	}

	public static BufferedImage removeBackgroud(String picFile)
			throws Exception {
		BufferedImage img = ImageIO.read(new File(picFile));
		int width = img.getWidth();
		int height = img.getHeight();
		for (int x = 0; x < width; ++x) {
			for (int y = 0; y < height; ++y) {
				if (isWhite(img.getRGB(x, y)) == 1) {
					img.setRGB(x, y, Color.WHITE.getRGB());
				} else {
					img.setRGB(x, y, Color.BLACK.getRGB());
				}
			}
		}
		return img;
	}

	public static List<BufferedImage> splitImage(BufferedImage img)
			throws Exception {
		List<BufferedImage> subImgs = new ArrayList<BufferedImage>();
		subImgs.add(img.getSubimage(10, 6, 8, 10));
		subImgs.add(img.getSubimage(19, 6, 8, 10));
		subImgs.add(img.getSubimage(28, 6, 8, 10));
		subImgs.add(img.getSubimage(37, 6, 8, 10));
		return subImgs;
	}

	public static Map<BufferedImage, String> loadTrainData() throws Exception {
		Map<BufferedImage, String> map = new HashMap<BufferedImage, String>();
		File dir = new File("train");
		File[] files = dir.listFiles();
		for (File file : files) {
			map.put(ImageIO.read(file), file.getName().charAt(0) + "");
		}
		return map;
	}

	public static String getSingleCharOcr(BufferedImage img,
			Map<BufferedImage, String> map) {
		String result = "";
		int width = img.getWidth();
		int height = img.getHeight();
		int min = width * height;
		for (BufferedImage bi : map.keySet()) {
			int count = 0;
			Label1: for (int x = 0; x < width; ++x) {
				for (int y = 0; y < height; ++y) {
					if (isWhite(img.getRGB(x, y)) != isWhite(bi.getRGB(x, y))) {
						count++;
						if (count >= min)
							break Label1;
					}
				}
			}
			if (count < min) {
				min = count;
				result = map.get(bi);
			}
		}
		return result;
	}

	public static String getAllOcr(String file) throws Exception {
		BufferedImage img = removeBackgroud(file);
		List<BufferedImage> listImg = splitImage(img);
		Map<BufferedImage, String> map = loadTrainData();
		String result = "";
		for (BufferedImage bi : listImg) {
			result += getSingleCharOcr(bi, map);
		}
		ImageIO.write(img, "JPG", new File("result//"+result+".jpg"));
		return result;
	}

	public static void downloadImage() {
		HttpClient httpClient = new HttpClient();
		GetMethod getMethod = new GetMethod(
				"http://www.puke888.com/authimg.php");
		for (int i = 0; i < 30; i++) {
			try {
				// 执行getMethod
				int statusCode = httpClient.executeMethod(getMethod);
				if (statusCode != HttpStatus.SC_OK) {
					System.err.println("Method failed: "
							+ getMethod.getStatusLine());
				}
				// 读取内容
				String picName = "img//" + i + ".jpg";
				InputStream inputStream = getMethod.getResponseBodyAsStream();
				OutputStream outStream = new FileOutputStream(picName);
				IOUtils.copy(inputStream, outStream);
				outStream.close();
				System.out.println("OK!");
			} catch (Exception e) {
				e.printStackTrace();
			} finally {
				// 释放连接
				getMethod.releaseConnection();
			}
		}
	}

	/**
	 * @param args
	 * @throws Exception
	 */
	public static void main(String[] args) throws Exception {
		for (int i = 0; i < 30; ++i) {
			String text = getAllOcr("img//" + i + ".jpg");
			System.out.println(i + ".jpg = " + text);
		}
	}
}