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Dim videoencodingprops As VideoEncodingProperties = CType(Me.mc.VideoDeviceController.GetMediaStreamProperties(MediaStreamType.VideoPreview), VideoEncodingProperties)
Dim softwarebmp As SoftwareBitmap = (Await Me.mc.GetPreviewFrameAsync(New Windows.Media.VideoFrame(BitmapPixelFormat.Bgra8, CInt(videoencodingprops.Width), CInt(videoencodingprops.Height)))).SoftwareBitmap
Dim writeablebmp As New WriteableBitmap(softwarebmp.PixelWidth, softwarebmp.PixelHeight)
softwarebmp.CopyToBuffer(writeablebmp.PixelBuffer)
Dim bmp As Drawing.Bitmap = CType(writeablebmp, Drawing.Bitmap)
Dim blobcntr As New AForge.Imaging.BlobCounter()
blobcntr.ProcessImage(bmp)
Dim blobs As AForge.Imaging.Blob() = blobcntr.GetObjectsInformation()
writeablebmp = CType(bmp, WriteableBitmap)
Me.imgPreview.Source = writeablebmp
This code displays a preview from a MediaCapture (Me.mc) in a UWP Image control (Me.imgPreview). However, it is displaying a big red X (1 pixel thick, corner to corner) on top of the WriteableBitmap / Image. I can still see the preview from the camera, so the red X is obviously part of the image. If I remove the following line:
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writeablebmp = CType(bmp, WriteableBitmap)
Then the red X is not displayed. The only places where bmp (the Drawing.Bitmap being converted & assigned to the WriteableBitmap in the line mentioned) is used is when it is declared and when I call ProcessImage. Could either of these lines be causing this? If they are (which I would find surprising), why is it using the corners, and why red? Any help would be appreciated, thanks.
