Это уже обсуждалось здесь :
IplImage* img=cvLoadImage("sample.jpg",3); // for example
HDC hdc = picturebox.GetDC()->m_hDC;
char m_chBmpBuf[2048];
BITMAPINFO *m_pBmpInfo =0;
m_pBmpInfo = (BITMAPINFO *)m_chBmpBuf;
m_pBmpInfo->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
m_pBmpInfo->bmiHeader.biWidth = img->width;
m_pBmpInfo->bmiHeader.biHeight = -img->height;
m_pBmpInfo->bmiHeader.biBitCount= 24;
m_pBmpInfo->bmiHeader.biPlanes = 1;
m_pBmpInfo->bmiHeader.biCompression = BI_RGB;
m_pBmpInfo->bmiHeader.biSizeImage = 0;
m_pBmpInfo->bmiHeader.biXPelsPerMeter = 0;
m_pBmpInfo->bmiHeader.biYPelsPerMeter = 0;
m_pBmpInfo->bmiHeader.biClrUsed = 0;
m_pBmpInfo->bmiHeader.biClrImportant = 0;
StretchDIBits(hdc, 0, 0, img->width, img->height,
0, 0, img->width, img->height,
img->imageData, m_pBmpInfo,
DIB_RGB_COLORS, SRCCOPY);