我用vb2012 directshow 编写的摄像头拍照程序，摄像头视频能够预览，但拍下的照片一片黑，代码如下：
Private Sub Button9_Click(sender As Object, e As EventArgs) Handles Button9.Click
Cursor.Current = Cursors.WaitCursor ' Release any previous buffer
If m_ip <> IntPtr.Zero Then
Marshal.FreeCoTaskMem(m_ip)
m_ip = IntPtr.Zero
End If 'capture image
m_ip = cam.Click()
Dim b As Bitmap
'Bitmap b = New Bitmap(cam.Width, cam.Height, cam.Stride, PixelFormat.Format24
bp
pRgb, m_ip)
b = New Bitmap(cam.Width, cam.Height, cam.Stride, PixelFormat.Format24bppRgb, m_ip)
' If the image is upsidedown
b.RotateFlip(RotateFlipType.RotateNoneFlipY)
PictureBox1.Image = b
If PictureBox1.Image IsNot Nothing Then
'pictureBox2
Cursor.Current = Cursors.Default
PictureBox1.Image.Save(Application.StartupPath + "/2.bmp")
End If
End Sub

我也有这样的问题

用emgucv或者forge.net
——来自 诺基亚 Lumia 925