Writing an Image to Memory

ImageMan can also be used to export images to memory blocks. To do this, an application uses the ImgXBeginWriteMem/ImgXEndWriteMem function pair instead of the ImgXBeginWrite/ImgXEndWrite functions. The following example illustrates writing a DIB to a TIFF file in memory:

#include "imgx.h"

HANDLE hJob, hMemBlk;

XINFO xInfo;

DWORD dwSize;

...

// lpBitmapInfo points to a BITMAPINFO structure

// lpRasterData points to our image data in DIB format

// xInfo has been initialized

hJob = ImgXBeginWriteMem("tif",lpBitmapInfo,NULL,&xInfo,NULL,0);

ImgXWriteBlock( hJob, nLines, lpRasterData, &xInfo );

ImgXEndWriteMem( hJob, &xInfo, &hMemBlk, &dwSize );

// hMemBlk now contains the handle of the memory block

// containing the image, and dwSize is the size of the

// image, in bytes. It is up to the calling app

// to free hMemBlk using GlobalFree before the app exits.

...

If we haven't said enough times already, we'll say it again here: It is up to your application to free the memory block returned from the ImgXEndWriteMem function. Failure to do so will result in a severe memory leak in your application, which is a bad thing.