Re: How image size can change using Intel Library

[jain]

I resize the bitmap but when i am trying to write the buffer into a BMP
File then i found that it is totally black image only.
below is the code snippet. let me know what is missing for setting the
color.

BYTE* pImageBuf = NULL;
int nScaleHeight = -m_bmpInfo.bmiHeader.biHeight / 2;
int nScaleWidth = m_bmpInfo.bmiHeader.biWidth / 2;

HDC ImgDestDC = NULL;
HBITMAP ImgDestBMP;
long lRet;

ImgDestDC = CreateCompatibleDC(NULL);
ImgDestBMP = CreateCompatibleBitmap(ImgDestDC, nScaleWidth,
nScaleHeight);
SelectObject(ImgDestDC, ImgDestBMP);


lRet = StretchDIBits(ImgDestDC, 0, 0, nScaleWidth, nScaleHeight, 0, 0,

m_bmpInfo.bmiHeader.biWidth, -m_bmpInfo.bmiHeader.biHeight,
buffer, &m_bmpInfo, DIB_RGB_COLORS, SRCCOPY);

if (lRet == GDI_ERROR) return NULL;

iBufferSize = nScaleWidth * nScaleHeight * 3;

BITMAPINFO ScaleBMI;
memset(&ScaleBMI, 0, sizeof(ScaleBMI));
ScaleBMI.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
ScaleBMI.bmiHeader.biWidth = nScaleWidth;
ScaleBMI.bmiHeader.biHeight = -nScaleHeight; // top-down image
ScaleBMI.bmiHeader.biPlanes = 1;
ScaleBMI.bmiHeader.biBitCount = 24;
ScaleBMI.bmiHeader.biCompression = BI_RGB;
ScaleBMI.bmiHeader.biSizeImage = iBufferSize;

pImageBuf = new unsigned char [iBufferSize];
lRet1 = GetDIBits(ImgDestDC, ImgDestBMP, 0, nScaleHeight, pImageBuf,
&ScaleBMI, DIB_RGB_COLORS);

WriteBitmapFile(pImageBuf);
if (lRet == GDI_ERROR) return NULL;

Parul