var
AMetaFile : TMetaFile;
AMFCanvas : TMetaFileCanvas;
JPEGImage : TJPEGImage;
begin
// assuming that you have an image in your JPEGImage
AMetaFile := TMetaFile.Create;
AMFCanvas := TMetaFileCanvas.Create(AMetaFile, GetDC(Self.Handle));
AMFCanvas.StretchDraw(Rect(0, 0, 1900, 1468), Photo);
AMFCanvas.Free;
// note that image is copied ONLY when you free Metafile canvas.