public static extern IntPtr HeifDecodeImage(HeifImageHandlePointer inHandle, ref HeifImagePointer outImg, HeifColorspace colorspace, HeifChroma chroma, HeifDecodingOptionsPointer options);
public static extern int HeifImageHandleGetLumaBitsPerPixel(HeifImageHandlePointer handle);
public static extern IntPtr HeifContextGetImageHandle(HeifContextPointer ctx, HeifItemId id, ref HeifImageHandlePointer imgHdl);
public static extern void HeifImageHandleRelease(HeifImageHandlePointer handle);
public static extern IntPtr HeifContextGetPrimaryImageHandle(HeifContextPointer ctx, ref HeifImageHandlePointer imgHdl);