一个VC轮廓提取的问题

2011-11-10 11:08:40 136 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

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OpenCV_提取直线、轮廓和区域 *提取直线、轮廓和区域之前的二值边缘分布图有两个缺点。首先，检测到的边缘过厚，这导致更加难以识别物体的边界；第二，通常不能找到这样的阈值：低到足以检测到图像中的所有重要的边缘同时又避免产生太多无关紧要的边缘。Canny算法试图解决这样的问题。使用cv::Canny()函数需要给出低阈值和高阈值两个阈值。canny算子通常是基于sobel算子，低阈值是宽松阈值，很多不需要的也被检测出来了；高阅读详情

那位大侠指点我一下下面这一句代码是什么意思：if((cur==0)||(cur==9))，为什么cur还会有等于9的时候
BOOL CDib::OutlineDIB(HDIB hDib)
{
LONG x,y;
int num;
int nw,n,ne,w,e,sw,s,se;
WaitCursorBegin();
HDIB hNewDib = NULL;
WORD wBitCount = DIBBitCount(hDib);
//将图像转化成24位图像，然后再处理
HANDLE h;
PLOGPALETTE plogPal;
h = GlobalAlloc(GHND, sizeof(DWORD) + sizeof(PALETTEENTRY)*256);
if (! h) return FALSE;
plogPal = (PLOGPALETTE)GlobalLock(h);
if (! plogPal) return FALSE;
plogPal->palVersion=PALVERSION;
plogPal->palNumEntries=256;
plogPal->palPalEntry[0].peGreen= 0;
plogPal->palPalEntry[0].peBlue= 0;
plogPal->palPalEntry[0].peRed= 0;
plogPal->palPalEntry[0].peFlags=NULL;
plogPal->palPalEntry[1].peGreen=255;
plogPal->palPalEntry[1].peBlue=255;
plogPal->palPalEntry[1].peRed=255;
plogPal->palPalEntry[1].peFlags=NULL;
HPALETTE hpl=CreatePalette(plogPal);
HPALETTE palold=NULL;
if (wBitCount != 8)
{
if(wBitCount!=24)
{
CPalette* Cpal=GetPalette();
palold=(HPALETTE)Cpal->GetSafeHandle();
}
hNewDib = ConvertDIBFormat(hDib,8, hpl);
}
else
hNewDib = ConvertDIBFormat(hDib,8, hpl);

if (! hNewDib)
{
WaitCursorEnd();
return FALSE;
}
//新的位图属性
WORD wDIBWidth = (WORD)DIBWidth(hNewDib);
WORD wDIBHeight = (WORD)DIBHeight(hNewDib);
WORD wBytesPerLine = (WORD)BytesPerLine(hNewDib);
DWORD dwImageSize = wBytesPerLine * wDIBHeight;
//锁定要处理的位图数据
HGLOBAL hFilteredBits = GlobalAlloc(GHND, dwImageSize);
if (!hFilteredBits)
{
WaitCursorEnd();
return FALSE;
}
LPBYTE lpPtr = (LPBYTE)GlobalLock(hFilteredBits);
LPBYTE lpDIB = (LPBYTE)GlobalLock(hNewDib);
LPBYTE lpDIBits = FindDIBBits(lpDIB);
unsigned char cur;
memcpy(lpPtr,lpDIBits, dwImageSize);
//开始处理
for (y=1;y<wDIBHeight-1;y++)
{
lpPtr=(unsigned char *)lpDIBits+(dwImageSize-wBytesPerLine-y*wBytesPerLine);
for (x=1;x<wDIBWidth-1;x++)
{
cur=(unsigned char)*(lpPtr+x);
if((cur==0)||(cur==9))//************************不懂不懂*****************
{
w=(unsigned char)*(lpPtr+x-1);
e=(unsigned char)*(lpPtr+x+1);
nw=(unsigned char)*(lpPtr+x+wBytesPerLine-1);
n=(unsigned char)*(lpPtr+x+wBytesPerLine);
ne=(unsigned char)*(lpPtr+x+wBytesPerLine+1);
sw=(unsigned char)*(lpPtr+x-wBytesPerLine-1);
s=(unsigned char)*(lpPtr+x-wBytesPerLine);
se=(unsigned char)*(lpPtr+x-wBytesPerLine+1);
num=nw+n+ne+w+e+sw+s+se;
//如果不是边界，将值设为9
if(num%9==0)
*(lpPtr+x)=(unsigned char)9;
}
}
}
for (y=1;y<wDIBHeight-1;y++)
{
lpPtr=(unsigned char *)lpDIBits+(dwImageSize-wBytesPerLine-y*wBytesPerLine);
for (x=1;x<wDIBWidth-1;x++)
{
cur=(unsigned char)*(lpPtr+x);
//如果不是边界，将值设为1,为白色
if(cur==9)
*(lpPtr+x)=(unsigned char)1;
}
}
//重建位图，变换回原来的位数
GlobalUnlock(hFilteredBits);
GlobalFree(hFilteredBits);
GlobalUnlock(hNewDib);
HDIB hTmp = NULL;
if (wBitCount != 8)
{
if(wBitCount ==24)
hTmp = ConvertDIBFormat(hNewDib, wBitCount, NULL);
else
hTmp = ConvertDIBFormat(hNewDib, wBitCount, palold);
}
else
hTmp = CopyHandle(hNewDib);
GlobalUnlock(h);
GlobalFree(h);
GlobalFree(hNewDib);
DWORD dwSize = GlobalSize(hTmp);
//将原先的位图数据替换成处理后的位图数据
memcpy((LPBYTE)GlobalLock(hDib), (LPBYTE)GlobalLock(hTmp), dwSize);
GlobalUnlock(hTmp);
GlobalUnlock(hDib);
WaitCursorEnd();
return TRUE;
}

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