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Freeimage的图片切割分块的处理。。。。尼玛突然感到头好晕。。。。。。。。。。。
/////////////////////////////////////////////////////////////////////////////////////////
//源代码
1、otsu阈值分割
/*
parameter: *image --- buffer for image
rows, cols --- size of image
x0, y0, dx, dy --- region of vector used for computing threshold
vvv --- debug option, is 0, no debug information outputed
*/
/*======================================================================*/
/* OTSU global thresholding routine */
/* takes a 2D unsigned char array pointer, number of rows, and */
/* number of cols in the array. returns the value of the threshold */
/*======================================================================*/
int CStatintDlg::otsu (unsigned char *image, int rows, int cols, int x0, int y0, int dx, int dy, int vvv)
{
unsigned char *np; // 图像指针
int thresholdValue=1; // 阈值
int ihist[256]; // 图像直方图，256个点
int i, j, k; // various counters
int n, n1, n2, gmin, gmax;
double m1, m2, sum, csum, fmax, sb;
// 对直方图置零...
memset(ihist, 0, sizeof(ihist));
gmin=255; gmax=0;
// 生成直方图
for (i = y0 + 1; i < y0 + dy - 1; i++) {
np = &image[i*cols+x0+1];
for (j = x0 + 1; j < x0 + dx - 1; j++) {
ihist[*np]++;
if(*np > gmax) gmax=*np;
if(*np < gmin) gmin=*np;
np++; /* next pixel */
}
}
// set up everything
sum = csum = 0.0;
n = 0;
for (k = 0; k <= 255; k++) {
sum += (double) k * (double) ihist[k]; /* x*f(x) 质量矩*/
n += ihist[k]; /* f(x) 质量 */
}
if (!n) {
// if n has no value, there is problems...
fprintf (stderr,"NOT NORMAL thresholdValue = 160\n");
return (160);
}
// do the otsu global thresholding method
fmax = -1.0;
n1 = 0;
for (k = 0; k < 255; k++) {
n1 += ihist[k];
if (!n1) { continue; }
n2 = n - n1;
if (n2 == 0) { break; }
csum += (double) k *ihist[k];
m1 = csum / n1;
m2 = (sum - csum) / n2;
sb = (double) n1 *(double) n2 *(m1 - m2) * (m1 - m2);
/* bbg: note: can be optimized. */
if (sb > fmax) {
fmax = sb;
thresholdValue = k;
}
}
// at this point we have our thresholding value
// debug code to display thresholding values
if ( vvv & 1 )
fprintf(stderr,"# OTSU: thresholdValue = %d gmin=%d gmax=%d\n",
thresholdValue, gmin, gmax);
return(thresholdValue);
}
//快速判别
void CStatintDlg::OnBnClickedDiscrimination()
{
if(m_kOrgImage.IsEmpty()) //there is no image we should exit from here
return;
size_t bpp = m_kOrgImage.GetBPP();
if(1 == bpp) return;
m_kOrgImage.ConvertToGreyscale();
BYTE *lpBits = m_kOrgImage.GetBits();
unsigned int width = m_kOrgImage.GetWidth();
unsigned int height = m_kOrgImage.GetHeight();
m_Threshold = otsu(lpBits,height,width,0,0,width,height,0);
TRACE1("otsu=%d\n\n",m_Threshold);
ASSERT(m_Threshold >0 && m_Threshold < 256);
//////////////////////////////////////////////////////////////////////////
unsigned int v = ( width - 1 ) / m_nBlockWidth + 1;
unsigned int h = ( height - 1 ) / m_nBlockheight + 1;
dMatrix Ratiomat(h,v); //比列矩阵
uMatrix BitMat(h,v); //0-1矩阵
long sFront,sBack;
double fRatio;
for(unsigned int j = 0; j < h; j ++ )
{
for(unsigned int i = 0; i < v; i ++ )
{
RECT rt;
rt.left = i * m_nBlockWidth;
rt.top = j * m_nBlockheight;
rt.right = rt.left + m_nBlockWidth;
rt.bottom = rt.top + m_nBlockheight;
if( rt.right > (LONG)width ){
rt.right = width;
}
if( rt.bottom > (LONG)height ){
rt.bottom = height;
}
FIBITMAP* pCut = ::FreeImage_Copy( m_kOrgImage.GetHandle(), rt.left, rt.top, rt.right, rt.bottom );
::FreeImage_GetHistogram(pCut , m_hgray, FICC_RGB);
sFront = 0;
sBack = 0;
for (unsigned int k = 0;k<256;k++)
{
if(k > m_Threshold)
sFront += m_hgray[k];
else
sBack += m_hgray[k];
}
if(0 == sBack) //防止处以0
fRatio = 1.0f;
else
fRatio = (double)sFront/(double)sBack;
Ratiomat[j] = fRatio;
if ( (abs(fRatio - m_fLowVal) > 1e-20 ) && (abs(fRatio - m_fHighVal) > 1e-20 ))
BitMat[j] = 1;
else
BitMat[j] = 0;
//举例怎么取矩阵的值
TRACE3("Ratiomat[%d][%d]=%f%%\n",j,i,fRatio*100);
if( pCut )
::FreeImage_DestroyICCProfile( pCut );
}
}
//////////////////////////////////////////////////////////////////////////
m_kOrgImage.Threshold(m_Threshold);
UpdateImage();
}
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