vb.net怎么从内存中读取bmp图片？

写入内存的参考代码如下，读取的图片为外界写入内存中的，请问要怎么实现？

  Dim bmpData As System.Drawing.Imaging.BitmapData = bmp.LockBits(rect, System.Drawing.Imaging.ImageLockMode.ReadWrite, bmp.PixelFormat)
            ' Get the address of the first line.   

            sdkimage._height = bmp.Height       ' 图片高度
            sdkimage._width = bmp.Width          ' 图片宽度
            sdkimage.data = bmpData.Scan0         '   位图中第一个像素数据的地址
            sdkimage._size = bmpData.Stride * bmp.Height   '数据大小

 Dim bytes() As Byte = ...
Dim ms1 As MemoryStream = new MemoryStream(bytes)
Dim bm As Bitmap = CType(Image.FromStream(ms1), Bitmap)
ms1.Close()