Image from SQL Database to CImage - c++

Question

I'm struggling at the moment and hope that someone can help me.
I have to get an Image out of a SQL database (like with SQLGetData) and than convert that data to a CImage so I can view it in my program.
Thanks for any help!
SQLGetData(m_Hstmt, col, SQL_C_BINARY, BinaryPtr, 0, &cbData)

Answer 1

The problem can be reduced to loading a CImage from a byte array, since that is what you get from SQLGetData.
You did not indicate whether you mean to use ATL or MFC, but in both cases it is a little bit awkward as there is no such thing as a public ::LoadFromBuffer function.
This answer should do:
https://stackoverflow.com/a/6759701/1132334
It explains how to create a bitmap structure from a byte buffer and construct a CImage from there.
It is going to be tricky if you need to handle different picture formats. In this case, write the raw bytes to a memory mapped file and then use the CImage::Load(IStream*) overload.
EDIT: its all been done before... https://stackoverflow.com/a/14035492/1132334 and https://stackoverflow.com/a/38710933/1132334

Answer 2

Thanks for all the replies so far. Acoording to #dlatikay answer, this is my code so far. But I'm not sure about the types and somehow my Image stayes black (when I save it to file system)
heres my code so far.
SQLLEN cbData;
CImage image;
BYTE* imgBits;
m_Rc = SQLGetData(m_Hstmt, 1, SQL_C_BINARY, imgBits, 0, &cbData);
if (SQL_SUCCEEDED(m_Rc))
{
width = 317;
height = 159;
BITMAPINFOHEADER bmInfohdr;
// Create the header info
bmInfohdr.biSize = sizeof(BITMAPINFOHEADER);
bmInfohdr.biWidth = width;
bmInfohdr.biHeight = -height;
bmInfohdr.biPlanes = 1;
bmInfohdr.biBitCount = 8 * 8;
bmInfohdr.biCompression = BI_RGB;
bmInfohdr.biSizeImage = width*height * 8;
bmInfohdr.biXPelsPerMeter = 0;
bmInfohdr.biYPelsPerMeter = 0;
bmInfohdr.biClrUsed = 0;
bmInfohdr.biClrImportant = 0;
BITMAPINFO bmInfo;
bmInfo.bmiHeader = bmInfohdr;
bmInfo.bmiColors[0].rgbBlue = 255;
// Allocate some memory and some pointers
unsigned char * p24Img = new unsigned char[width*height * 3];
BYTE *pTemp, *ptr;
pTemp = (BYTE*)imgBits;
ptr = p24Img;
// Convert image from RGB to BGR
for (DWORD index = 0; index < width*height; index++)
{
unsigned char r = *(pTemp++);
unsigned char g = *(pTemp++);
unsigned char b = *(pTemp++);
*(ptr++) = b;
*(ptr++) = g;
*(ptr++) = r;
}
// Create the CImage
image.Create(width, height, 8, NULL);
image.Save(_T("c:\\temp\\image1.bmp")); // for testing
}