📄 第3章 图象的平滑(去噪声)、锐化.htm
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</SPAN>if(g1>g2){</P>
<P
style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>if(g2>g3) g=g2;</P>
<P
style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>else{</P>
<P
style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>if(g1>g3) g=g3;</P>
<P
style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>else g=g1;</P>
<P
style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>}</P>
<P
style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>}</P>
<P
style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>else{ //g1<=g2</P>
<P
style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>if(g1>g3) g=g1;</P>
<P
style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>else{ </P>
<P
style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>if(g2>g3) g=g3;</P>
<P
style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>else g=g2;</P>
<P
style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>}</P>
<P
style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>}</P>
<P
style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>*lpTempPtr=(BYTE)g; //<SPAN style="FONT-FAMILY: 宋体">存入新的缓冲区内</SPAN></P>
<P
style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>}</P>
<P style="LINE-HEIGHT: 18pt"><SPAN lang=EN-US>hDc=GetDC(hWnd);</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN> </SPAN>
if(hBitmap!=NULL)</P>
<P style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>DeleteObject(hBitmap);</P>
<P style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>//<SPAN style="FONT-FAMILY: 宋体">产生新的位图</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN
lang=EN-US>hBitmap=CreateDIBitmap(hDc,(LPBITMAPINFOHEADER)lpTempImgData,</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN lang=EN-US>(LONG)CBM_INIT,</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN lang=EN-US>(LPSTR)lpTempImgData+</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN
lang=EN-US>sizeof(BITMAPINFOHEADER)+</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN
lang=EN-US>NumColors*sizeof(RGBQUAD),</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>
(LPBITMAPINFO)lpTempImgData,</P>
<P style="LINE-HEIGHT: 18pt"><SPAN lang=EN-US>DIB_RGB_COLORS);</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN lang=EN-US>if(Hori) //</SPAN><SPAN
style="FONT-FAMILY: 宋体">取不同的结果文件名</SPAN></P>
<P
style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>hf=_lcreat("c:\\hmedian.bmp",0);</P>
<P style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>else</P>
<P
style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>hf=_lcreat("c:\\vmedian.bmp",0);</P>
<P style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>_lwrite(hf,(LPSTR)&bf,sizeof(BITMAPFILEHEADER)); </P>
<P style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>_lwrite(hf,(LPSTR)lpTempImgData,BufSize);</P>
<P style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>_lclose(hf);</P>
<P style="LINE-HEIGHT: 18pt"><SPAN lang=EN-US>//</SPAN><SPAN
style="FONT-FAMILY: 宋体">释放内存及资源</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN> </SPAN>
ReleaseDC(hWnd,hDc);</P>
<P style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>LocalUnlock(hTempImgData);</P>
<P style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>LocalFree(hTempImgData);</P>
<P style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>GlobalUnlock(hImgData);</P>
<P style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>return TRUE;</P>
<P style="LINE-HEIGHT: 18pt"><SPAN lang=EN-US>}</SPAN></P>
<H2><SPAN lang=EN-US>3.3</SPAN> <SPAN lang=EN-US></SPAN><A
name=_Toc486331876></A><A name=_Toc486332876></A><A name=_Toc486338985></A><A
name=_Toc454810850></A><A
name=_Toc454856624><SPAN><SPAN>锐化</SPAN></SPAN></A></H2>
<P style="LINE-HEIGHT: 18pt"><SPAN style="FONT-FAMILY: 宋体">锐化</SPAN><SPAN
lang=EN-US>(sharpening)</SPAN><SPAN
style="FONT-FAMILY: 宋体">和平滑恰恰相反，它是通过增强高频分量来减少图象中的模糊，因此又称为高通滤波</SPAN><SPAN
lang=EN-US>(high pass filter)</SPAN><SPAN
style="FONT-FAMILY: 宋体">。锐化处理在增强图象边缘的同时增加了图象的噪声。</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN
style="FONT-FAMILY: 宋体">常用的锐化模板是拉普拉斯</SPAN><SPAN
lang=EN-US>(Laplacian)</SPAN><SPAN style="FONT-FAMILY: 宋体">模板</SPAN><SPAN
lang=EN-US>(</SPAN><SPAN style="FONT-FAMILY: 宋体">见</SPAN><SPAN
lang=EN-US>(3.4)</SPAN><SPAN style="FONT-FAMILY: 宋体">式</SPAN><SPAN
lang=EN-US>)</SPAN><SPAN
style="FONT-FAMILY: 宋体">，又是个数学家的名字，可见学好数学，走遍天下都不怕。</SPAN></P>
<P style="LINE-HEIGHT: 18pt; TEXT-ALIGN: center" align=center><SPAN
lang=EN-US><SUB><IMG height=75 src="第3章 图象的平滑(去噪声)、锐化.files/image067.gif"
width=100 v:shapes="_x0000_i1081"> </SUB></SPAN></P>
<P style="LINE-HEIGHT: 18pt; TEXT-ALIGN: right" align=right><SPAN
lang=EN-US>(3.4)</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN
style="FONT-FAMILY: 宋体">容易看出拉普拉斯模板的作法：先将自身与周围的</SPAN><SPAN
lang=EN-US>8</SPAN><SPAN
style="FONT-FAMILY: 宋体">个象素相减，表示自身与周围象素的差别；再将这个差别加上自身作为新象素的灰度。可见，如果一片暗区出现了一个亮点，那么锐化处理的结果是这个亮点变得更亮，增加了图象的噪声。</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN
style="FONT-FAMILY: 宋体">因为图象中的边缘就是那些灰度发生跳变的区域，所以锐化模板在边缘检测中很有用，这一点将在后面详细介绍。</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN style="FONT-FAMILY: 宋体">图</SPAN><SPAN
lang=EN-US>3.1</SPAN><SPAN style="FONT-FAMILY: 宋体">经过拉普拉斯模板处理后，如图</SPAN><SPAN
lang=EN-US>3.4</SPAN><SPAN style="FONT-FAMILY: 宋体">所示</SPAN></P>
<P style="LINE-HEIGHT: 18pt; TEXT-ALIGN: center" align=center><SPAN
lang=EN-US><IMG height=193 src="第3章 图象的平滑(去噪声)、锐化.files/image068.gif" width=174
v:shapes="_x0000_i1082"> </SPAN></P>
<P style="LINE-HEIGHT: 18pt; TEXT-ALIGN: center" align=center><B><SPAN
style="FONT-FAMILY: 宋体">图</SPAN>3.4 </B><B><SPAN
style="FONT-FAMILY: 宋体">锐化</SPAN><SPAN lang=EN-US></SPAN></B></P>
<P style="LINE-HEIGHT: 18pt"><SPAN
style="FONT-FAMILY: 宋体">下面给出的程序是一个通用的</SPAN><SPAN lang=EN-US>3</SPAN><SPAN
style="FONT-FAMILY: 宋体">×</SPAN><SPAN lang=EN-US>3</SPAN><SPAN
style="FONT-FAMILY: 宋体">模板的函数，其中第二参数为模板类型，为如下定义的常量：</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN lang=EN-US>#define TEMPLATE_SMOOTH_BOX 1
//Box</SPAN><SPAN style="FONT-FAMILY: 宋体">平滑模板</SPAN></P>
<P style="LINE-HEIGHT: 18pt">#define TEMPLATE_SMOOTH_GAUSS 2 //<SPAN
style="FONT-FAMILY: 宋体">高斯平滑模板</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN lang=EN-US>#define TEMPLATE_SHARPEN_LAPLACIAN
3 //</SPAN><SPAN style="FONT-FAMILY: 宋体">拉普拉斯锐化模板</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN style="FONT-FAMILY: 宋体">对应的模板数组如下</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN lang=EN-US>int
Template_Smooth_Box[9]={1,1,1,1,1,1,1,1,1};</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN lang=EN-US>int
Template_Smooth_Gauss[9]={1,2,1,2,4,2,1,2,1};</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN lang=EN-US>int
Template_Sharpen_Laplacian[9]={-1,-1,-1,-1,9,-1,-1,-1,-1};</SPAN><SPAN
lang=EN-US style="FONT-SIZE: 9pt"></SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN
style="FONT-FAMILY: 宋体">以后我们碰到其它的模板，仍然要用这个函数，所做的操作只是增加一个常量标识，及其对应的模板数组。</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN
style="FONT-FAMILY: 宋体">要注意的是，运算后如果出现了大于</SPAN><SPAN lang=EN-US>255</SPAN><SPAN
style="FONT-FAMILY: 宋体">或者小于</SPAN><SPAN lang=EN-US>0</SPAN><SPAN
style="FONT-FAMILY: 宋体">的点，称为溢出，溢出点的处理通常是截断，即大于</SPAN><SPAN
lang=EN-US>255</SPAN><SPAN style="FONT-FAMILY: 宋体">时，令其等于</SPAN><SPAN
lang=EN-US>255</SPAN><SPAN style="FONT-FAMILY: 宋体">；小于</SPAN><SPAN
lang=EN-US>0</SPAN><SPAN style="FONT-FAMILY: 宋体">时，取其绝对值。</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN
style="FONT-FAMILY: 宋体">这段程序和前几章介绍的代码许多地方是很相似的，所以注释简单一些。程序中并没有用到那种分解成两个一维模板的快速算法，你如果有兴趣，可以自己编着试试。</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN lang=EN-US>BOOL TemplateOperation(HWND hWnd,
int TemplateType)</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN lang=EN-US>{</SPAN></P>
<P style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>DWORD
OffBits,BufSize;</P>
<P style="LINE-HEIGHT: 18pt">LPBITMAPINFOHEADER lpImgData;</P>
<P style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>LPSTR
lpPtr;</P>
<P style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>HLOCAL
hTempImgData;</P>
<P style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>LPBITMAPINFOHEADER lpTempImgData;</P>
<P style="LINE-HEIGHT: 18pt"><SPAN>
</SPAN>LPSTR
lpTempPtr;</P>
<P style="LINE-HEIGHT: 18pt"><SPAN>
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