读取bmp图片数据

 1 public  void getBMPImage(String source) throws Exception {
 2
 3          clearNData();                        //清除数据保存区
 4          FileInputStream fs = null;
 5
 6         try {
 7             fs = new FileInputStream(source);
 8             int bfLen = 14;
 9             byte bf[] = new byte[bfLen];
10             fs.read(bf, 0, bfLen); // 读取14字节BMP文件头
11             int biLen = 40;
12             byte bi[] = new byte[biLen];
13             fs.read(bi, 0, biLen); // 读取40字节BMP信息头
14             // 源图宽度
15             nWidth = (((int) bi[7] & 0xff) << 24)
16                     | (((int) bi[6] & 0xff) << 16)
17                     | (((int) bi[5] & 0xff) << 8) | (int) bi[4] & 0xff;
18             // 源图高度
19             nHeight = (((int) bi[11] & 0xff) << 24)
20                     | (((int) bi[10] & 0xff) << 16)
21                     | (((int) bi[9] & 0xff) << 8) | (int) bi[8] & 0xff;
22             // 位数
23             nBitCount = (((int) bi[15] & 0xff) << 8) | (int) bi[14] & 0xff;
24             // 源图大小
25             int nSizeImage = (((int) bi[23] & 0xff) << 24)
26                     | (((int) bi[22] & 0xff) << 16)
27                     | (((int) bi[21] & 0xff) << 8) | (int) bi[20] & 0xff;
28             // 对24位BMP进行解析
29             if (nBitCount == 24){
30                 int nPad = (nSizeImage / nHeight) - nWidth * 3;
31                 nData = new int[nHeight * nWidth];
32                 nB=new int[nHeight * nWidth];
33                 nR=new int[nHeight * nWidth];
34                 nG=new int[nHeight * nWidth];
35                 byte bRGB[] = new byte[(nWidth + nPad) * 3 * nHeight];
36                 fs.read(bRGB, 0, (nWidth + nPad) * 3 * nHeight);
37                 int nIndex = 0;
38                 for (int j = 0; j < nHeight; j++){
39                     for (int i = 0; i < nWidth; i++) {
40                         nData[nWidth * (nHeight - j - 1) + i] = (255 & 0xff) << 24
41                                 | (((int) bRGB[nIndex + 2] & 0xff) << 16)
42                                  | (((int) bRGB[nIndex + 1] & 0xff) << 8)
43                                 | (int) bRGB[nIndex] & 0xff;
44                         nB[nWidth * (nHeight - j - 1) + i]=(int) bRGB[nIndex]& 0xff;
45                         nG[nWidth * (nHeight - j - 1) + i]=(int) bRGB[nIndex+1]& 0xff;
46                         nR[nWidth * (nHeight - j - 1) + i]=(int) bRGB[nIndex+2]& 0xff;
47                         nIndex += 3;
48                     }
49                     nIndex += nPad;
50                 }
51  //               Toolkit kit = Toolkit.getDefaultToolkit();
52  //               image = kit.createImage(new MemoryImageSource(nWidth, nHeight,
53  //                       nData, 0, nWidth));
54 /*
55 //调试数据的读取
56                 FileWriter fw = new FileWriter("C:\\Documents and Settings\\Administrator\\My Documents\\nDataRaw.txt");//创建新文件
57                 PrintWriter out = new PrintWriter(fw);
58                 for(int j=0;j<nHeight;j++){
59                  for(int i=0;i<nWidth;i++){
60                   out.print((65536*256+nData[nWidth * (nHeight - j - 1) + i])+"_"
61                     +nR[nWidth * (nHeight - j - 1) + i]+"_"
62                     +nG[nWidth * (nHeight - j - 1) + i]+"_"
63                     +nB[nWidth * (nHeight - j - 1) + i]+" ");
64
65                  }
66                  out.println("");
67                 }
68                 out.close();
69 */
70             }
71         }
72         catch (Exception e) {
73             e.printStackTrace();
74             throw new Exception(e);
75         }
76         finally {
77             if (fs != null) {
78                 fs.close();
79             }
80         }
81      //   return image;
82     }