我用StretchBlt(image2.Canvas.Handle, 0, 0, image2.Width, image2.Height, image1.Canvas.Handle, 0, 0,
    image1.Picture.Width, image1.Picture.Height, SRCCOPY);
将一bmp图形缩小(如300*420---->120*168),图形变得不可辨认或是血肉模糊,
怎么样才能避免这样呢?(PhotoShop中就不会)