Java實現圖片比對-逐像素對比

圖片對比的另外一種方式是經過將圖片每個像素的RGB值提取出來，而後比較兩個圖片每個像素的RGB值；該方法的問題是速度比較慢，須要消耗較大的空間； 

private static InputStream getImageStreamFromWeb(String urlAddress) {  
        URL url = null;  
        HttpURLConnection conn = null;  
        try {  
            url = new URL(urlAddress);  
            conn = (HttpURLConnection) url.openConnection();  
            if (conn.getResponseCode() == 200) {  
                InputStream in = conn.getInputStream();  
                return in;  
            } else {  
                throw new PictureNotFoundError("can not found #ADD# picture: "  
                        + urlAddress);  
            }  
        } catch (Exception e) {  
        }  
        return null;  
    }  
  
public static String[][] getPX(InputStream in) {  
        int[] rgb = new int[3];  
  
        BufferedImage bi = null;  
        try {  
            bi = ImageIO.read(in);  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
  
        int width = bi.getWidth();  
        int height = bi.getHeight();  
        int minx = bi.getMinX();  
        int miny = bi.getMinY();  
        String[][] list = new String[width][height];  
        for (int i = minx; i < width; i++) {  
            for (int j = miny; j < height; j++) {  
                int pixel = bi.getRGB(i, j);  
                rgb[0] = (pixel & 0xff0000) >> 16;  
                rgb[1] = (pixel & 0xff00) >> 8;  
                rgb[2] = (pixel & 0xff);  
                list[i][j] = rgb[0] + "," + rgb[1] + "," + rgb[2];  
            }  
        }  
        rgb = null;  
        return list;  
  
    }  
  
public static boolean compareImage(InputStream img1, InputStream img2) {  
        // 分析圖片類似度 begin  
        String[][] list1 = getPX(img1);  
        String[][] list2 = getPX(img2);  
        int xiangsi = 0;  
        int busi = 0;  
        int i = 0, j = 0;  
        for (String[] strings : list1) {  
            if ((i + 1) == list1.length) {  
                continue;  
            }  
            for (int m = 0; m < strings.length; m++) {  
                try {  
                    String[] value1 = list1[i][j].toString().split(",");  
                    String[] value2 = list2[i][j].toString().split(",");  
                    int k = 0;  
                    for (int n = 0; n < value2.length; n++) {  
                        if (Math.abs(Integer.parseInt(value1[k])  
                                - Integer.parseInt(value2[k])) < 5) {  
                            xiangsi++;  
                        } else {  
                            busi++;  
                        }  
                    }  
                } catch (RuntimeException e) {  
                    continue;  
                }  
                j++;  
            }  
            i++;  
        }  
  
        list1 = list2;  
        list2 = list1;  
        i = 0;  
        j = 0;  
        for (String[] strings : list1) {  
            if ((i + 1) == list1.length) {  
                continue;  
            }  
            for (int m = 0; m < strings.length; m++) {  
                try {  
                    String[] value1 = list1[i][j].toString().split(",");  
                    String[] value2 = list2[i][j].toString().split(",");  
                    int k = 0;  
                    for (int n = 0; n < value2.length; n++) {  
                        if (Math.abs(Integer.parseInt(value1[k])  
                                - Integer.parseInt(value2[k])) < 5) {  
                            xiangsi++;  
                        } else {  
                            busi++;  
                        }  
                    }  
                } catch (RuntimeException e) {  
                    continue;  
                }  
                j++;  
            }  
            i++;  
        }  
        String baifen = "";  
        try {  
            baifen = ((Double.parseDouble(xiangsi + "") / Double  
                    .parseDouble((busi + xiangsi) + "")) + "");  
            baifen = baifen.substring(baifen.indexOf(".") + 1, baifen  
                    .indexOf(".") + 3);  
        } catch (Exception e) {  
            baifen = "0";  
        }  
        if (baifen.length() <= 0) {  
            baifen = "0";  
        }  
        if (busi == 0) {  
            baifen = "100";  
        }  
          
        list1 = null;  
        list2 = null;  
          
        if (!baifen.equals("100")) {  
            return false;  
        } else {  
            return true;  
        }  
  
    }