简单的验证码识别

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

import javax.imageio.ImageIO;

public class ImagePreProcess {
	
	//去除噪点
	public static int isWhite(int colorInt) {
		Color color = new Color(colorInt);
		if (color.getRed() + color.getGreen() + color.getBlue() > 590) {
			return 1;
		}
		return 0;
	}
	//移除背景
	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;
	}
	//将要识别的图片拆分为单个字母的图片
	public static List<BufferedImage> splitImage(BufferedImage img)
			throws Exception {
		List<BufferedImage> subImgs = new ArrayList<BufferedImage>();
		//此处的数字应该根据验证码的大小做相应调整
		subImgs.add(img.getSubimage(25, 0, 12, 25));
		subImgs.add(img.getSubimage(38, 0, 11, 25));
		subImgs.add(img.getSubimage(48, 0, 11, 25));
		subImgs.add(img.getSubimage(58, 0, 11, 25));
		return subImgs;
	}
	//加载验证码模板库
	public static Map<BufferedImage, String> loadTrainData(String trainPath) throws Exception {
		Map<BufferedImage, String> map = new HashMap<BufferedImage, String>();
		File dir = new File(trainPath);
		File[] files = dir.listFiles();
		for (File file : files) {
			if(file.getName().endsWith("jpg"))
				map.put(ImageIO.read(file), file.getName().charAt(0) + "");
		}
		return map;
	}
	//进行对比识别
	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 < bi.getWidth(); ++x) {
				for (int y = 0; y < height && y < bi.getWidth(); ++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;
	}
	//识别的入口
	public static String getAllOcr(String file) throws Exception {
		BufferedImage img = removeBackgroud(file);
		List<BufferedImage> listImg = splitImage(img);
		Map<BufferedImage, String> map = loadTrainData("C:/test/train");
		String result = "";
		for (BufferedImage bi : listImg) {
			result += getSingleCharOcr(bi, map);
		}
		ImageIO.write(img, "JPG", new File("C:/test/result/"+result+".jpg"));
		return result;
	}


	/**
	 * @param args
	 * @throws Exception
	 */
	public static void main(String[] args) throws Exception {
		String text = getAllOcr("C:/test/src.jpeg");
		System.out.println("jpg = " + text);
	}
}