PanoramicMappedImage

Programming Questions
2

Hello @MoDiver,

when you say ringbuffer control do you mean the ActiveX control? You also seem to use the object oriented wrappers. Then you don’t need the ActiveX controls. We don’t have many VB.Net users, this is why we don’t have examples. Sorry. Still I recommend reading:

https://forum.commonvisionblox.com/t/getting-started-with-cvb-net/246?u=parsd

The C# in there is easily translated to VB.Net as the objects are the same. There also the ring buffer is explained.

PanoramicImage

I start with the code:

Sub AcquisitionLoop(device As Device)
  Dim stream = device.Stream

  stream.RingBuffer.LockMode = RingBufferLockMode.On
  stream.RingBuffer.ChangeCount(6, DeviceUpdateMode.UpdateDeviceImage)

  stream.Start()
  Dim lastImage As StreamImage = Nothing
  Try
    While True
      Dim newImage = stream.Wait()
      If lastImage IsNot Nothing Then
        ProcessImages(lastImage, newImage) 
      End If

      If lastImage IsNot Nothing
        lastImage.Dispose()
      End If
      lastImage = newImage
    End While
  Finally
    If lastImage IsNot Nothing
      lastImage.Dispose()
    End If
    stream.Abort()
  End Try
End Sub

Sub ProcessImages(imageTop As Image, imageBottom As Image)
  Dim combinedImage = PanoramicMappedImage.CreateVertical(imageTop, imageBottom)
  
  YourSearch(combinedImage)
End Sub

You store your previous image and process then two at once without copying any data. To be able to do that you need to increase the ring buffer size and change the lock mode to manual (LockMode.On). The size increase is necessary to prevent loosing frames. And you now need to explicitly unlock your unused images via .Dispose(). If you don’t do that your ring buffer runs out of usable memory and your application blocks in the .Wait call.

Image to Bitmap

Just add the reference to Stemmer.Cvb.Extensions.dll to your project and make sure that you import the namespace Stemmer.Cvb.Extensions. Then you can simply call .ToBitmap() on a Stemmer.Cvb.Image.

I hope that helps.

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