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标题: [多媒体] 视频捕捉 [打印本页]

作者: tiggerwang 时间: 2008-3-3 03:02 标题: 视频捕捉

请教高手，我是菜鸟
我用有一个webcamera, 运行了视频，有了视频显示，我想每隔几秒把视频的桢抓出来，判断桢中红颜色的位置
怎么做？谢谢

作者: tiggerwang 时间: 2008-3-3 05:44 标题: 视频捕捉

我的代码：引用AVICAP
我先把视频缓冲的内容读到内存，然后把内存的数据写成bitmap，看看我写的对吗？
Public Function MyFrameCheck(hDestBmp As Long) As Long

Dim VideoHeader As VIDEOHDR
Dim VideoData() As Byte

Dim X As Integer, y As Integer
Dim tDBmpInfo As BITMAP
Dim dBits() As Byte

'//Fill VideoHeader with data at lpVHdr
   RtlMoveMemory VarPtr(VideoHeader), lpvhdr, Len(VideoHeader)

'// Make room for data
   ReDim VideoData(VideoHeader.dwBytesUsed)

'//Copy data into the memory array
   RtlMoveMemory VarPtr(VideoData(0)), VideoHeader.lpData, VideoHeader.dwBytesUsed


'get bitmap
   Call GetObject(hDestBmp, Len(tDBmpInfo), tDBmpInfo)
   Call SetBitmapBits(hDestBmp, tDBmpInfo.bmWidthBytes * tDBmpInfo.bmHeight, VarPtr(VideoData(0)))


   Image1.Picture.Handle = hDestBmp

Dim c1 As Long             'Picture1的RGB颜色

Dim r As Boolean 'R分量
Dim g As Boolean
Dim b As Boolean

  For X = 0 To tDBmpInfo.bmWidth - 1
For y = 0 To tDBmpInfo.bmHeight - 1
      c1 = Image1.Point(X, y)
      r = c1 And &HFF
      g = (c1 And 65280) / 256
      b = (c1 And &HFF0000) / 65536

      If r = True And g = False And b = False Then

      Label1.Caption = X
      Label2.Caption = y
      Exit For
      End If


Next
Next




End Function

作者: Nothing 时间: 2008-3-3 21:32

原理是对的，可能一些操作上还要测试一下

作者: tiggerwang 时间: 2008-3-5 08:55 标题: thanks

我知道了，从视频读出来得就是颜色值，我没必要再转换成BMP格式了，直接操作就可以了，希望同行借鉴

作者: Nothing 时间: 2008-3-5 16:13

因为图像会模糊一点，可能会有一些变色，应当取一个色值范围而不是一个值。

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