提问人：user2959923 提问时间：5/19/2023 更新时间：5/19/2023 访问量：25
EMGU的。CV System.Runtime.InteropServices.SEHException，同时在 VB.NET 中在某个区域上方绘制轮廓 （VectorOfVectorOfPoint）
EMGU.CV System.Runtime.InteropServices.SEHException while drawing contours (VectorOfVectorOfPoint) above a certain area in VB.NET
问：
我试图简单地在图像上某个区域上方绘制所有轮廓。 在我得到框架和轮廓后，我在迭代 contorus 时出现以下异常：
System.Runtime.InteropServices.SEHException： '外部组件具有 抛出了一个例外。
代码如下（它位于计时器内）：
' cyclic routine
Dim frame As New Emgu.CV.Image(Of Bgr, Byte)(1920, 1080)
Dim currFr As Emgu.CV.Image(Of Bgr, Byte) = videoCap.QueryFrame().ToImage(Of Bgr, Byte)
' copy frame
frame = currFr.Resize(1, CvEnum.Inter.Lanczos4)
Dim imgContours As New Image(Of Gray, Byte)(frame.Size)
If backgroundFrame Is Nothing Then
' save this frame as background for subtraction
backgroundFrame = frame
Else
' background subtraction
Dim elFrame As New Image(Of Bgr, Byte)(frame.Size)
elFrame = frame - backgroundFrame
' get contours from image (as VectorOfVectorOfPoint)
imgContours = elFrame.Convert(Of Gray, Byte).ThresholdBinary(New Gray(80), New Gray(255))
Dim contours As New Emgu.CV.Util.VectorOfVectorOfPoint()
Dim hier As New Mat()
CvInvoke.FindContours(imgContours, contours, hier, CvEnum.RetrType.External, CvEnum.ChainApproxMethod.ChainApproxSimple)
' draw all contours on the original frame of blue
CvInvoke.DrawContours(frame, contours, -1, New MCvScalar(255, 0, 0), 5)
' iterate through contours
For j As Integer = 0 To contours.Length - 1
' if the current contour area is above a threshold
If CvInvoke.ContourArea(contours(j)) > threshold Then <-------- HERE I GET THE EXCEPTION
' draw the current contour of red
CvInvoke.DrawContours(frame, contours, j, New MCvScalar(0, 0, 255), 5)
End If
Next
End If
' display the frame in the PictureBox
picFrame.Image = frame.ToBitmap
答：
0赞
user2959923
5/19/2023
#1
我设法让它工作。 我不知道为什么，但代码需要从：
' iterate through contours
For j As Integer = 0 To contours.Length - 1
' if the current contour area is above a threshold
If CvInvoke.ContourArea(contours(j)) > threshold Then
自：
' iterate through contours
Dim cont As Integer = contours.Size
For j As Integer = 0 To cont - 1
Using cnt As Util.VectorOfPoint = contours(j)
' if the current contour area is above a threshold
Dim area As Double = CvInvoke.ContourArea(cnt)
If area > threshold Then
' draw the bounding box of the contour in red
frame.Draw(CvInvoke.BoundingRectangle(cnt), New Bgr(0, 0, 255), 5)
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