java验证码识别--3

(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。)

前面的验证码背景都比较简单，用亮度稍微区分一下就可以去掉背景

来看个稍微复杂一点的

1。图片预处理

     怎么去掉背景干扰呢。

     可以注意到每个验证码数字或字母都是同一颜色，所以把验证码平均分成5份

    计算每个区域的颜色分布，除了白色之外，颜色值最多的就是验证码的颜色

    因此很容易将背景去掉

代码：

public static BufferedImage removeBackgroud(String picFile) throws Exception { BufferedImage img = ImageIO.read(new File(picFile)); img = img.getSubimage(1, 1, img.getWidth() - 2, img.getHeight() - 2); int width = img.getWidth(); int height = img.getHeight(); double subWidth = (double) width / 5.0; for (int i = 0; i < 5; i++) { Map<Integer, Integer> map = new HashMap<Integer, Integer>(); for (int x = (int) (1 + i * subWidth); x < (i + 1) * subWidth && x < width - 1; ++x) { for (int y = 0; y < height; ++y) { if (isWhite(img.getRGB(x, y)) == 1) continue; if (map.containsKey(img.getRGB(x, y))) { map.put(img.getRGB(x, y), map.get(img.getRGB(x, y)) + 1); } else { map.put(img.getRGB(x, y), 1); } } } int max = 0; int colorMax = 0; for (Integer color : map.keySet()) { if (max < map.get(color)) { max = map.get(color); colorMax = color; } } for (int x = (int) (1 + i * subWidth); x < (i + 1) * subWidth && x < width - 1; ++x) { for (int y = 0; y < height; ++y) { if (img.getRGB(x, y) != colorMax) { img.setRGB(x, y, Color.WHITE.getRGB()); } else { img.setRGB(x, y, Color.BLACK.getRGB()); } } } } return img; }

处理成这样了，基本就跟验证码识别--2一样了，只是黑白换了一下而已。

2。分割原理和3。训练原理，4。识别都水到渠成了。

 

识别结果如下，识别率100%

上面的处理之后的图片和识别结果，下面是原始图片

完整源码：

public class ImagePreProcess3 { private static Map<BufferedImage, String> trainMap = null; private static int index = 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 int isWhite(int colorInt) { Color color = new Color(colorInt); if (color.getRed() + color.getGreen() + color.getBlue() > 600) { return 1; } return 0; } public static BufferedImage removeBackgroud(String picFile) throws Exception { BufferedImage img = ImageIO.read(new File(picFile)); img = img.getSubimage(1, 1, img.getWidth() - 2, img.getHeight() - 2); int width = img.getWidth(); int height = img.getHeight(); double subWidth = (double) width / 5.0; for (int i = 0; i < 5; i++) { Map<Integer, Integer> map = new HashMap<Integer, Integer>(); for (int x = (int) (1 + i * subWidth); x < (i + 1) * subWidth && x < width - 1; ++x) { for (int y = 0; y < height; ++y) { if (isWhite(img.getRGB(x, y)) == 1) continue; if (map.containsKey(img.getRGB(x, y))) { map.put(img.getRGB(x, y), map.get(img.getRGB(x, y)) + 1); } else { map.put(img.getRGB(x, y), 1); } } } int max = 0; int colorMax = 0; for (Integer color : map.keySet()) { if (max < map.get(color)) { max = map.get(color); colorMax = color; } } for (int x = (int) (1 + i * subWidth); x < (i + 1) * subWidth && x < width - 1; ++x) { for (int y = 0; y < height; ++y) { if (img.getRGB(x, y) != colorMax) { img.setRGB(x, y, Color.WHITE.getRGB()); } else { img.setRGB(x, y, Color.BLACK.getRGB()); } } } } return img; } public static BufferedImage removeBlank(BufferedImage img) throws Exception { int width = img.getWidth(); int height = img.getHeight(); int start = 0; int end = 0; Label1: for (int y = 0; y < height; ++y) { for (int x = 0; x < width; ++x) { if (isBlack(img.getRGB(x, y)) == 1) { start = y; break Label1; } } } Label2: for (int y = height - 1; y >= 0; --y) { for (int x = 0; x < width; ++x) { if (isBlack(img.getRGB(x, y)) == 1) { end = y; break Label2; } } } return img.getSubimage(0, start, width, end - start + 1); } public static List<BufferedImage> splitImage(BufferedImage img) throws Exception { List<BufferedImage> subImgs = new ArrayList<BufferedImage>(); int width = img.getWidth(); int height = img.getHeight(); List<Integer> weightlist = new ArrayList<Integer>(); for (int x = 0; x < width; ++x) { int count = 0; for (int y = 0; y < height; ++y) { if (isBlack(img.getRGB(x, y)) == 1) { count++; } } weightlist.add(count); } for (int i = 0; i < weightlist.size();i++) { int length = 0; while (i < weightlist.size() && weightlist.get(i) > 0) { i++; length++; } if (length > 2) { subImgs.add(removeBlank(img.getSubimage(i - length, 0, length, height))); } } return subImgs; } public static Map<BufferedImage, String> loadTrainData() throws Exception { if (trainMap == null) { Map<BufferedImage, String> map = new HashMap<BufferedImage, String>(); File dir = new File("train3"); File[] files = dir.listFiles(); for (File file : files) { map.put(ImageIO.read(file), file.getName().charAt(0) + ""); } trainMap = map; } return trainMap; } 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; if (Math.abs(bi.getWidth()-width) > 2) continue; int widthmin = width < bi.getWidth() ? width : bi.getWidth(); int heightmin = height < bi.getHeight() ? height : bi.getHeight(); Label1: for (int x = 0; x < widthmin; ++x) { for (int y = 0; y < heightmin; ++y) { if (isBlack(img.getRGB(x, y)) != isBlack(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("result3//" + result + ".jpg")); return result; } public static void downloadImage() { HttpClient httpClient = new HttpClient(); GetMethod getMethod = new GetMethod("http://game.tom.com/checkcode.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 = "img3//" + i + ".jpg"; InputStream inputStream = getMethod.getResponseBodyAsStream(); OutputStream outStream = new FileOutputStream(picName); IOUtils.copy(inputStream, outStream); outStream.close(); System.out.println(i + "OK!"); } catch (Exception e) { e.printStackTrace(); } finally { // 释放连接 getMethod.releaseConnection(); } } } public static void trainData() throws Exception { File dir = new File("temp3"); File[] files = dir.listFiles(); for (File file : files) { BufferedImage img = removeBackgroud("temp3//" + file.getName()); List<BufferedImage> listImg = splitImage(img); if (listImg.size() == 5) { for (int j = 0; j < listImg.size(); ++j) { ImageIO.write(listImg.get(j), "JPG", new File("train3//" + file.getName().charAt(j) + "-" + (index++) + ".jpg")); } } } } /** * @param args * @throws Exception */ public static void main(String[] args) throws Exception { //trainData(); // downloadImage(); for (int i = 0; i < 30; ++i) { String text = getAllOcr("img3//" + i + ".jpg"); System.out.println(i + ".jpg = " + text); } } }