Simple VB.Net Video/Webcam Capture

[bangonkali]

I think there are not much samples given for VB.NET programmers here in EmguCV. So i just think it may help a lot of people if examples are added in the Wiki. I hope this one helps too.

Code: Select all

Imports Emgu.CV
Imports Emgu.CV.Structure
Imports Emgu.CV.Util
Imports Emgu.CV.UI

Public Class frmMain
    Dim imgFrame As Image(Of Bgr, Byte)
    Dim vidCapture As Capture

    Private Sub frmMain_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        vidCapture = New Capture() ' Put the proper arguments in here
        AddHandler Application.Idle, AddressOf AppIdle
    End Sub

    Public Sub AppIdle(ByVal sender As System.Object, ByVal e As System.EventArgs)
        imgFrame = vidCapture.QueryFrame
        imgBox.Image = imgFrame ' this is where captured image go.
    End Sub
End Class

[MIG400]

Hi, thanks for help, I'm using your code and work, I haven't a webcam right now but I capture images from a .avi,

vidCapture = New Capture("video.avi")

I'm having a problem cause the file .avi is in colors but when I captures the video is in gray, I'm using

Dim imgFrame As Image(Of Bgr, Byte)

Like de example. What I'm doing bad?

Thanks again.

[cke]

hi, what if i want to do a face detection on the webcam capture?

[bangonkali]

Hi, thanks for help, I'm using your code and work, I haven't a webcam right now but I capture images from a .avi,

vidCapture = New Capture("video.avi")

I'm having a problem cause the file .avi is in colors but when I captures the video is in gray, I'm using

Dim imgFrame As Image(Of Bgr, Byte)

Like de example. What I'm doing bad?

Thanks again.

Sorry for the late reply. But i'm quite sure that if your video is colored the code should also output colored frames since we're not limiting it to "Image(Of Gray, Byte)", perhaps the problem lies on the decoding of the video. Try to test on different codecs to see the effects. Perhaps the problem's on the codec.

[bangonkali]

hi, what if i want to do a face detection on the webcam capture?

It should look something like this:

Code: Select all

imgFrame = New Image(Of Bgr, Byte)(file)
For Each face As MCvAvgComp In imgFrame.DetectHaarCascade(objectToDetect)(0)
        imgFrame.Draw(face.rect, New Bgr(Color.Red), 2)
Next

Where file is a string path to the image file, and objectToDetect is declared as:

Code: Select all

Dim objectToDetect As New HaarCascade(Application.StartupPath & "\haarcascade_frontalface_alt2.xml")

... where "Application.StartupPath & "\haarcascade_frontalface_alt2.xml" points to the appropriate haar file. In this example, rectangles are drawn on each face after they're found.

[cke]

thanks bangonkali, i've done that already.. but my problem now is, when i try to put imgFrame as the frame capture inside an image viewer control, the displayed capture slows down because of the detection process. i can't figure out what to do. can you help me? i'm also planning to put an automatic face recognition in my project. thanks again!

[MIG400]

Thanks for help me bangonkali, I'm getting a WebCam now I will try again and post my experience.


Mariano.

[MIG400]

I'm getting colors now with my webcam, thanks.

Mariano.