请教VC中怎么把不同格式的图片（Jpeg,Png,Bmp,Gif.）读入规定尺寸的buffer（Bitmap 矩阵）

/**
 * Renders an image based on the specified GraphicInfo structure. Image will be rendered to specified height
 * and width to specified buffer.
 *
 * @param    graphicType            Graphic type, Jpeg, Png, Dib or BMP.
 * @param    pImageStream        Input stream of graphic.
 * @param    imageSize            Size of graphic in bytes or number of bytes that can be
 *                                read from above stream.
 * @param    width                Desired width of rendered graphic.
 * @param    height                Desired height of rendered graphic.
 * @param    pImageData            Pointer to a buffer where image will be rendered.
 *  */
void ImageHelper::renderBitmapGraphic(GraphicType graphicType, InputStream* pImageStream, int32_t streamSize, int32_t width, 
                                      int32_t height, int32_t* pImageData)
{
//函数体
}