chap01.htm

数字图像处理入门. 一位图像处理高手写的书. 从图像处理的最基础开始,然后慢慢以一些例子做说明,进入图像处理的更高阶段.学习图像处理不可多得的比较朴实的书

lang=EN-US>}</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>//</span><span style='font-family:宋体;
&quot;Times New Roman&quot;'>将</span><span lang=EN-US>BITMAPFILEHEADER</span><span
style='font-family:宋体;"Times New Roman"'>结构从文件中读出，填写到</span><span lang=EN-US>bf</span><span
style='font-family:宋体;"Times New Roman"'>中</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>_lread(hf,(LPSTR)&amp;bf,sizeof(BITMAPFILEHEADER)); </span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>//</span><span style='font-family:宋体;
&quot;Times New Roman&quot;'>将</span><span lang=EN-US>BITMAPINFOHEADER</span><span
style='font-family:宋体;"Times New Roman"'>结构从文件中读出，填写到</span><span lang=EN-US>bi</span><span
style='font-family:宋体;"Times New Roman"'>中</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>_lread(hf,(LPSTR)&amp;bi,sizeof(BITMAPINFOHEADER));</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>//</span><span style='font-family:宋体;
&quot;Times New Roman&quot;'>我们定义了一个宏</span> #define WIDTHBYTES(i)&nbsp;&nbsp;&nbsp; 
    ((i+31)/32*4)<span style='font-family:宋体;"Times New Roman";"Times New Roman"'>上面曾经</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>//</span><span style='font-family:宋体;
&quot;Times New Roman&quot;'>提到过，每一行的字节数必须是</span><span lang=EN-US>4</span><span
style='font-family:宋体;"Times New Roman"'>的整倍数，只要调用</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>//WIDTHBYTES(bi.biWidth*bi.biBitCount)</span><span style='font-family:
宋体;&quot;Times New Roman&quot;'>就能完成这一换算。举一个例</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>//</span><span style='font-family:宋体;
&quot;Times New Roman&quot;'>子，对于</span><span lang=EN-US>2</span><span
style='font-family:宋体;"Times New Roman"'>色图，如果图象宽是</span><span lang=EN-US>31</span><span
style='font-family:宋体;"Times New Roman"'>，则每一行需要</span><span lang=EN-US>31</span><span
style='font-family:宋体;"Times New Roman"'>位存储，合</span><span lang=EN-US>3</span><span style='font-family:
宋体;&quot;Times New Roman&quot;'>个</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>//</span><span style='font-family:宋体;
&quot;Times New Roman&quot;'>字节加</span><span lang=EN-US>7</span><span
style='font-family:宋体;"Times New Roman"'>位，因为字节数必须是</span><span lang=EN-US>4</span><span
style='font-family:宋体;"Times New Roman"'>的整倍数，所以应该是</span><span lang=EN-US>4</span><span
style='font-family:宋体;"Times New Roman"'>，而此时的</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>//biWidth=31,biBitCount=1,WIDTHBYTES(31*1)=4</span><span
style='font-family:宋体;"Times New Roman"'>，和我们设想的一样。</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>//</span><span style='font-family:宋体;
&quot;Times New Roman&quot;'>再举一个</span><span lang=EN-US>256</span><span
style='font-family:宋体;"Times New Roman"'>色的例子，如果图象宽是</span><span lang=EN-US>31</span><span
style='font-family:宋体;"Times New Roman"'>，则每一行需要</span><span lang=EN-US>31</span><span
style='font-family:宋体;"Times New Roman"'>个字节存</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>//</span><span style='font-family:宋体;
&quot;Times New Roman&quot;'>储，因为字节数必须是</span><span lang=EN-US>4</span><span
style='font-family:宋体;"Times New Roman"'>的整倍数，所以应该是</span><span lang=EN-US>32</span><span
style='font-family:宋体;"Times New Roman"'>，而此时的</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>//biWidth=31,biBitCount=8,WIDTHBYTES(31*8)=32</span><span
style='font-family:宋体;"Times New Roman"'>，我们设想的一样。你可</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>//</span><span style='font-family:宋体;
&quot;Times New Roman&quot;'>以多举几个例子来验证一下</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>//LineBytes</span><span style='font-family:宋体;"Times New Roman";"Times New Roman"'>为每一行的字节数</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>LineBytes=(DWORD)WIDTHBYTES(bi.biWidth*bi.biBitCount);</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>//ImgSize</span><span style='font-family:宋体;"Times New Roman";"Times New Roman"'>为实际的图象数据占用的字节数</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>ImgSize=(DWORD)LineBytes*bi.biHeight;</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>//NumColors</span><span style='font-family:宋体;"Times New Roman";"Times New Roman"'>为实际用到的颜色数</span> 
    <span
style='font-family:宋体;"Times New Roman"'>，即调色板数组中的颜色个数</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>if(bi.biClrUsed!=0)</span></p>
  <p style='line-height:
18.0pt'><span lang=EN-US>//</span><span style='font-family:宋体;"Times New Roman";"Times New Roman"'>如果</span><span
lang=EN-US>bi.biClrUsed</span><span style='font-family:宋体;"Times New Roman";"Times New Roman"'>不为零，即为实际用到的颜色数</span></p>
  <p style='line-height:
18.0pt'><span lang=EN-US>NumColors=(DWORD)bi.biClrUsed; </span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>else //</span><span style='font-family:宋体;"Times New Roman";"Times New Roman"'>否则，用到的颜色数为</span><span
lang=EN-US>2<sup>biBitCount</sup></span><span style='font-family:宋体;"Times New Roman";"Times New Roman"'>。</span></p>
  <p style='line-height:
18.0pt'><span lang=EN-US>switch(bi.biBitCount){</span></p>
  <p style='line-height:
18.0pt'><span lang=EN-US>case 1:</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>NumColors=2;</span></p>
  <p style='line-height:18.0pt'><span>&nbsp;&nbsp; </span> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; break;</p>
  <p style='line-height:18.0pt;'><span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
    </span>case 4:</p>
  <p style='line-height:
18.0pt'><span lang=EN-US>NumColors=16;</span></p>
  <p style='line-height:18.0pt'><span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
    </span>&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; break;</p>
  <p style='line-height:18.0pt'><span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>case 
    8:</p>
  <p style='line-height:18.0pt'><span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
    </span> NumColors=256;</p>
  <p style='line-height:18.0pt'><span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
    </span> break;</p>
  <p style='line-height:18.0pt'><span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>case 
    24:</p>
  <p style='line-height:18.0pt'><span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
    </span> NumColors=0; //<span style='font-family:
宋体;&quot;Times New Roman&quot;'>对于真彩色图，没用到调色板</span></p>
  <p style='line-height:18.0pt'><span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
    </span> break;</p>
  <p style='line-height:18.0pt'><span
lang=EN-US>default: //</span><span style='font-family:宋体;"Times New Roman";"Times New Roman"'>不处理其它的颜色数，认为出错。</span></p>
  <p style='line-height:
18.0pt'><span lang=EN-US>MessageBox(hWnd,&quot;Invalid color numbers!&quot;,&quot;Error 
    Message&quot;,</span></p>
  <p style='line-height:
18.0pt'><span lang=EN-US>MB_OK|MB_ICONEXCLAMATION);</span></p>
  <p style='line-height:
18.0pt'><span lang=EN-US>_lclose(hf);</span></p>
  <p style='line-height:18.0pt'><span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
    </span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
    return FALSE; //<span style='font-family:宋体;
&quot;Times New Roman&quot;'>关闭文件，返回</span><span lang=EN-US>FALSE</span></p>
  <p style='line-height:
18.0pt'><span lang=EN-US>}</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>if(bf.bfOffBits!=(DWORD)(NumColors*sizeof(RGBQUAD)+</span></p>
  <p style='line-height:
18.0pt'><span lang=EN-US>sizeof(BITMAPFILEHEADER)+</span></p>
  <p style='line-height:
18.0pt'><span lang=EN-US>sizeof(BITMAPINFOHEADER)))</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>{</span></p>
  <p style='line-height:
18.0pt'><span lang=EN-US>//</span><span style='font-family:宋体;"Times New Roman";"Times New Roman"'>计算出的偏移量与实际偏移量不符，一定是颜色数出错</span></p>
  <p style='line-height:18.0pt'><span>&nbsp;&nbsp; </span> MessageBox(hWnd,&quot;Invalid 
    color numbers!&quot;,&quot;Error Message&quot;,</p>
  <p style='line-height:
18.0pt'><span lang=EN-US>MB_OK|MB_ICONEXCLAMATION);</span></p>
  <p style='line-height:
18.0pt'><span lang=EN-US>_lclose(hf);</span></p>
  <p style='line-height:
18.0pt'><span lang=EN-US>return FALSE; //</span><span style='font-family:宋体;
&quot;Times New Roman&quot;'>关闭文件，返回</span><span
lang=EN-US>FALSE</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>}</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>bf.bfSize=sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER)+</span></p>
  <p style='line-height:
18.0pt'><span lang=EN-US>NumColors*sizeof(RGBQUAD)+ImgSize;</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>//</span><span style='font-family:宋体;
&quot;Times New Roman&quot;'>分配内存，大小为</span><span lang=EN-US>BITMAPINFOHEADER</span><span
style='font-family:宋体;"Times New Roman"'>结构长度加调色板</span><span lang=EN-US>+</span><span
style='font-family:宋体;"Times New Roman"'>实际位图</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>if((hImgData=GlobalAlloc(GHND,(DWORD)</span></p>
  <p style='line-height:
18.0pt'><span lang=EN-US>(sizeof(BITMAPINFOHEADER)+</span></p>
  <p style='line-height:
18.0pt'><span lang=EN-US>NumColors*sizeof(RGBQUAD)+</span></p>
  <p style='line-height:
18.0pt'><span lang=EN-US>ImgSize)))==NULL)</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>{</span></p>
  <p style='line-height:
18.0pt'><span lang=EN-US>//</span><span style='font-family:宋体;"Times New Roman";"Times New Roman"'>分配内存错误</span></p>
  <p style='line-height:
18.0pt'><span lang=EN-US>MessageBox(hWnd,&quot;Error alloc memory!&quot;,&quot;ErrorMessage&quot;,MB_OK|</span></p>
  <p style='line-height:18.0pt'><span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
    </span>MB_ICONEXCLAMATION);</p>
  <p style='line-height:
18.0pt'><span lang=EN-US>_lclose(hf);</span></p>
  <p style='line-height:
18.0pt'><span lang=EN-US>return FALSE; //</span><span style='font-family:宋体;
&quot;Times New Roman&quot;'>关闭文件，返回</span><span
lang=EN-US>FALSE</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>}</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>//</span><span style='font-family:宋体;
&quot;Times New Roman&quot;'>指针</span><span lang=EN-US>lpImgData</span><span
style='font-family:宋体;"Times New Roman"'>指向该内存区</span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>lpImgData=(LPBITMAPINFOHEADER)GlobalLock(hImgData); </span></p>
  <p style='line-height:18.0pt'><span
lang=EN-US>//</span><span style='font-family:宋体;
&quot;Times New Roman&quot;'>文件指针重新定位到</span><span lang=EN-US>BITMAPINFOHEADER</span><span
style='font-family:宋体;"Times New Roman"'>开