24位bmp剪切并转存为单色bmp
24位bmp剪切并转存为单色bmp
折磨我好久啊。。。可惜弄好了又用不上了。。。
知识关键:
Bmp文件有个重要特性,那就是对于数据区域而言,每行的数据它必须凑满4字节,如果没有满,则用冗余的数据来补齐。
程序关键:
bi.biSizeImage = (bi.biWidth*bi.biBitCount+31)/32*4*bi.biHeight; //生成的新图像的文件大小
/* 实现原图像坐标的转换读取 */
pitch = SrcWidth%4;
int realPitch = i*pitch;
BYTE b = pDIBData[(i*SrcWidth+j)*3+realPitch];
BYTE g = pDIBData[(i*SrcWidth+j)*3+1+realPitch];
BYTE r = pDIBData[(i*SrcWidth+j)*3+2+realPitch];
输入input.bmp 输出output.bmp
主要参考:百度百科_BMP http://baike.baidu.com/view/7671.htm (BMP文件存储格式)
BMP图象解析 http://www.vckbase.com/document/viewdoc/?id=1786 (坐标位置转换)
__________________________________________________________________________________
void CutPhoto(long StartLeft, long StartTop, long TargetWidth, long TargetHeight)
{
char FileName[32];
sprintf(FileName, "input.bmp");
BYTE* pDIBData;
BITMAPFILEHEADER bf;
BITMAPINFOHEADER bi;
RGBQUAD rgb[2]={{0,0,0,0},{255,255,255,0}};
CFile fileR(FileName, CFile::modeRead);
fileR.Read(&bf, sizeof(BITMAPFILEHEADER));
fileR.Read(&bi, sizeof(BITMAPINFOHEADER));
long SrcWidth=bi.biWidth;
long SrcHeight=bi.biHeight;
int nSize = bf.bfSize - bi.biSize;
pDIBData = new BYTE[nSize];
fileR.Read(pDIBData, nSize);
fileR.Close();
StartTop = SrcHeight - TargetHeight - StartTop;
bi.biWidth = TargetWidth;
bi.biHeight = TargetHeight;
bi.biBitCount = 1;
bi.biXPelsPerMeter = 0;
bi.biYPelsPerMeter = 0;
bi.biSizeImage = (bi.biWidth*bi.biBitCount+31)/32*4*bi.biHeight;
sprintf(FileName, "output.bmp");
CFile file(FileName, CFile::modeWrite|CFile::modeCreate);
bf.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + sizeof(RGBQUAD)*2;
bf.bfSize = bf.bfOffBits + bi.biSizeImage;
file.Write(&bf, sizeof(BITMAPFILEHEADER));
file.Write(&bi, sizeof(BITMAPINFOHEADER));
file.Write(rgb, 2*sizeof(RGBQUAD));
BYTE writein = 0;
int pitch = SrcWidth%4;
int k, pitchcount;
for(int i=StartTop;i<StartTop+TargetHeight;i++)
{
pitchcount = 0;
k=0;
int realPitch = i*pitch;
for(int j=StartLeft;j<StartLeft+TargetWidth;j++)
{
BYTE b = pDIBData[(i*SrcWidth+j)*3+realPitch];
BYTE g = pDIBData[(i*SrcWidth+j)*3+1+realPitch];
BYTE r = pDIBData[(i*SrcWidth+j)*3+2+realPitch];
writein<<=1;
if ((r+g+b)/3>127)
writein|=1;
if (++k==8)
{
pitchcount++;
file.Write(&writein, 1);
writein = 0;
k=0;
}
}
if (k != 0)
{
writein<<=(8-k);
file.Write(&writein, 1);
pitchcount++;
}
if (pitchcount%4 != 0)
{
writein = 0;
for (j=0; j<4-pitchcount%4; j++)
file.Write(&writein, 1);
}
}
file.Close();
delete pDIBData;
pDIBData = NULL;
}
知识关键:
Bmp文件有个重要特性,那就是对于数据区域而言,每行的数据它必须凑满4字节,如果没有满,则用冗余的数据来补齐。
程序关键:
bi.biSizeImage = (bi.biWidth*bi.biBitCount+31)/32*4*bi.biHeight; //生成的新图像的文件大小
/* 实现原图像坐标的转换读取 */
pitch = SrcWidth%4;
int realPitch = i*pitch;
BYTE b = pDIBData[(i*SrcWidth+j)*3+realPitch];
BYTE g = pDIBData[(i*SrcWidth+j)*3+1+realPitch];
BYTE r = pDIBData[(i*SrcWidth+j)*3+2+realPitch];
输入input.bmp 输出output.bmp
主要参考:百度百科_BMP http://baike.baidu.com/view/7671.htm (BMP文件存储格式)
BMP图象解析 http://www.vckbase.com/document/viewdoc/?id=1786 (坐标位置转换)
__________________________________________________________________________________
void CutPhoto(long StartLeft, long StartTop, long TargetWidth, long TargetHeight)
{
char FileName[32];
sprintf(FileName, "input.bmp");
BYTE* pDIBData;
BITMAPFILEHEADER bf;
BITMAPINFOHEADER bi;
RGBQUAD rgb[2]={{0,0,0,0},{255,255,255,0}};
CFile fileR(FileName, CFile::modeRead);
fileR.Read(&bf, sizeof(BITMAPFILEHEADER));
fileR.Read(&bi, sizeof(BITMAPINFOHEADER));
long SrcWidth=bi.biWidth;
long SrcHeight=bi.biHeight;
int nSize = bf.bfSize - bi.biSize;
pDIBData = new BYTE[nSize];
fileR.Read(pDIBData, nSize);
fileR.Close();
StartTop = SrcHeight - TargetHeight - StartTop;
bi.biWidth = TargetWidth;
bi.biHeight = TargetHeight;
bi.biBitCount = 1;
bi.biXPelsPerMeter = 0;
bi.biYPelsPerMeter = 0;
bi.biSizeImage = (bi.biWidth*bi.biBitCount+31)/32*4*bi.biHeight;
sprintf(FileName, "output.bmp");
CFile file(FileName, CFile::modeWrite|CFile::modeCreate);
bf.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + sizeof(RGBQUAD)*2;
bf.bfSize = bf.bfOffBits + bi.biSizeImage;
file.Write(&bf, sizeof(BITMAPFILEHEADER));
file.Write(&bi, sizeof(BITMAPINFOHEADER));
file.Write(rgb, 2*sizeof(RGBQUAD));
BYTE writein = 0;
int pitch = SrcWidth%4;
int k, pitchcount;
for(int i=StartTop;i<StartTop+TargetHeight;i++)
{
pitchcount = 0;
k=0;
int realPitch = i*pitch;
for(int j=StartLeft;j<StartLeft+TargetWidth;j++)
{
BYTE b = pDIBData[(i*SrcWidth+j)*3+realPitch];
BYTE g = pDIBData[(i*SrcWidth+j)*3+1+realPitch];
BYTE r = pDIBData[(i*SrcWidth+j)*3+2+realPitch];
writein<<=1;
if ((r+g+b)/3>127)
writein|=1;
if (++k==8)
{
pitchcount++;
file.Write(&writein, 1);
writein = 0;
k=0;
}
}
if (k != 0)
{
writein<<=(8-k);
file.Write(&writein, 1);
pitchcount++;
}
if (pitchcount%4 != 0)
{
writein = 0;
for (j=0; j<4-pitchcount%4; j++)
file.Write(&writein, 1);
}
}
file.Close();
delete pDIBData;
pDIBData = NULL;
}