How to display camera streams on WinForm?

[Skullface9512]

I am developing a C# UI using IC4 camera. How can I display camera stream in real-time on the WinForm? Meanwhile, how to modify parameters such as resolution and exposure time for the camera and make it change in real-time? Is there any control that can be used?

[TIS-Tim]

For display, just put a ic4.WinForms.Display on your form, as shown in the Windows Forms example applications: https://github.com/TheImagingSource/ic4-examples/tree/master/dotnet/winforms/DialogApp-net6/DialogApp-net6

The example program also shows how to display the pre-built property dialog that allows the user to adjust settings.

[Skullface9512]

Recently i'm working on putting the camera video stream into a UI WinForm and show a cross in image, the code i modified like that:

namespace CameraTest.Forms
{
    public partial class Calibration : Form
    {
        public Calibration()
        {
            InitializeComponent();
            ic4.Library.Init(apiLogLevel: ic4.LogLevel.Info, logTargets: ic4.LogTarget.WinDebug);
        }

        private void btnOpen_Click(object sender, EventArgs e)
        {
            ic4.Grabber grabber = new ic4.Grabber();

            var selectedDeviceInfo = ic4.WinForms.Dialogs.ShowSelectDeviceDialog(this);
            if (selectedDeviceInfo == null)
                return;
            grabber.DeviceOpen(selectedDeviceInfo);
            var sink = new ic4.QueueSink(ic4.PixelFormat.BGR8, maxOutputBuffers: 1);
            sink.FramesQueued += (s, args) =>
            {
                // Get the new buffer from the sink
                // Buffer is disposed at the end of the using-block to allow re-queue
                using (var buffer = sink.PopOutputBuffer())
                {
                    // Create an OpenCVSharp view onto the buffer
                    // This view is only valid while the buffer itself exists,
                    // which is guaranteed by them both not being passed out of this function
                    var wrap = buffer.CreateOpenCvWrap();

                    int width = wrap.Width;
                    int height = wrap.Height;
                    //Console.WriteLine(width);
                    //Console.WriteLine(height);

                    OpenCvSharp.Point startPoint1 = new OpenCvSharp.Point(Convert.ToInt32(width / 2) - 500, Convert.ToInt32(height / 2));
                    OpenCvSharp.Point endPoint1 = new OpenCvSharp.Point(Convert.ToInt32(width / 2) + 500, Convert.ToInt32(height / 2)); 
                    OpenCvSharp.Point startPoint2 = new OpenCvSharp.Point(Convert.ToInt32(width / 2), Convert.ToInt32(height / 2) - 500);
                    OpenCvSharp.Point endPoint2 = new OpenCvSharp.Point(Convert.ToInt32(width / 2), Convert.ToInt32(height / 2) + 500);
                    Scalar color = new Scalar(0, 255, 0);
                    int thickness = 2;

                    Cv2.Line(wrap, startPoint1, endPoint1, color, thickness);
                    Cv2.Line(wrap, startPoint2, endPoint2, color, thickness);
                    display1.DisplayBuffer(buffer);
                }
            };

            // Start the stream
            grabber.StreamSetup(sink, display1,StreamSetupOption.AcquisitionStart);

            //grabber.StreamStop();
        }
    }
}

the running result is very strange, sometimes screen likely fix the first frame and don't change, sometimes it can show the video stream, but see no cross in image.

[TIS-Tim]

The display should not be used manually and as stream target at the same time.

This line manually displays the modified image:

display1.DisplayBuffer(buffer);

This line automatically displays all (original) images:

grabber.StreamSetup(sink, display1,StreamSetupOption.AcquisitionStart);

Don't pass the display to StreamSetup and the cross should be displayed correctly.

[Skullface9512]

Ok, it works, and if i want to close this window through a button, how can i add this function.

[TIS-Tim]

"This Window"? You mean your Windows Form? Form.Close.

[Skullface9512]

Just stop the video stream when click the button.

[TIS-Tim]

To stop the video stream, call grabber.StreamStop()

[Skullface9512]

Where should I put this function in the above code and set relative button?

[TIS-Tim]

I am very sorry, but Windows Forms programming really is outside the scope of this forum.

[Skullface9512]

Rencently i tried to compile C# program in Win32, but come across some problems like that:
System.NotSupportedException:“IC Imaging Control 4 .NET does not support x86 Windows applications. Change your project settings to x64, or, when the project is set to 'Any CPU' disable 'Prefer 32-bit' in the build options.”
How can i solve this problem, thanks.

[TIS-Tim]

You do exactly as the error message says. ic4 is not supported in 32-bit applications.

[Skullface9512]

Hello, I want to take 4 pictures and display them in real-time on display 1, but I found that using sink TryPopOutputBuffer can only capture 3 images. Do you have any good methods?

 var sink = new ic4.QueueSink(ic4.PixelFormat.BGR8, maxOutputBuffers: 10);

 int save_num = 0;
 string file_name = $"{picture_dir}/MTF";
 if (!Directory.Exists(file_name))
 {
     Directory.CreateDirectory(file_name);
 }
 Console.WriteLine("file_name" + file_name);
 List<double> value = new List<double>();
 value.Add(0.0);
 value.Add(500.0);
 value.Add(1000.0);
 value.Add(1920.0);


 this.grabberL.StreamStop();
 this.grabberL.DeviceClose();
 var grabber2 = new ic4.Grabber();
 var selectedDeviceInfo2 = selectedDeviceInfoL;
 if (selectedDeviceInfo2 == null) { Console.WriteLine("无法读到设备"); return; }
 grabber2.DeviceOpen(selectedDeviceInfo2);


 Console.WriteLine("程序已启动，参数已传递。");
 sink.FramesQueued += (s, args) =>
 {
     Console.WriteLine("value.Count:"+ value.Count);
     if (sink.TryPopOutputBuffer(out ic4.ImageBuffer buffer) && save_num < value.Count+10)
     {

         try
         {
             string zoomingValue = value[save_num].ToString();
             Process.Start(motorFilePath, zoomingValue);
             buffer.SaveAsPng($"{file_name}/{save_num}.png");
             Console.WriteLine($"Saved image {$"{file_name}/{save_num}.png"}");
             display1.DisplayBuffer(buffer);
             //AnalyseMTFLeft(save_num);


         }
         catch (IC4Exception err)
         {
             Console.WriteLine($"Failed to save buffer: {err.Message}");
         }
         save_num++;
     }
 };
 Console.WriteLine("22222");
 // Start the stream
 grabber2.StreamSetup(sink, StreamSetupOption.AcquisitionStart);
 //this.grabberL = grabber2;
 Console.WriteLine("333333");```

and logcat is as follows:

```file_nameE:\WorkProject\Agent\CameraTest\bin\x64\Debug\picture/MTF
程序已启动，参数已传递。
22222
333333
value.Count:4
Saved image E:\WorkProject\Agent\CameraTest\bin\x64\Debug\picture/MTF/0.png
value.Count:4
Saved image E:\WorkProject\Agent\CameraTest\bin\x64\Debug\picture/MTF/1.png
value.Count:4
Saved image E:\WorkProject\Agent\CameraTest\bin\x64\Debug\picture/MTF/2.png```

[TIS-Tim]

When posting code, please try to create a Minimal, Reproducible Example.

Your code does not show what happens after you call StreamSetup, so for all I know your program may just exit.

One wild guess: You do not dispose the buffer objects you get in the callback. Since garbage collection takes time, your program owns all buffers and no buffers are available for new images to be received.

Add a finally block to your try statement and call buffer.Dispose() to make sure the buffer is returned to the driver.

[Skullface9512]

Hi，I tried method you advised before, and the modified code is：

{

    string motorFilePath = @"E:\WorkProject\Agent\CameraTest\bin\x64\Debug\exe\CH347Demo.exe";
    var sink = new ic4.QueueSink(ic4.PixelFormat.BGR8, maxOutputBuffers: 1);

    int save_num = 0;
    string file_name = $"{picture_dir}/VID";
    if (!Directory.Exists(file_name))
    {
        Directory.CreateDirectory(file_name);
    }
    Console.WriteLine("file_name" + file_name);
    List<double> value = new List<double>();
    value.Add(120.0);
    value.Add(28.0);
    value.Add(26.0);
    value.Add(25.3);
    value.Add(24.9);
    value.Add(23.5);
    value.Add(22.0);
    value.Add(21.0);
    value.Add(0.0);


    this.grabberL.StreamStop();
    this.grabberL.DeviceClose();
    var grabber2 = new ic4.Grabber();
    var selectedDeviceInfo2 = selectedDeviceInfoL;
    if (selectedDeviceInfo2 == null) { Console.WriteLine("can't read the device"); return; }
    grabber2.DeviceOpen(selectedDeviceInfo2);

    sink.FramesQueued += (s, args) =>
    {
        Console.WriteLine("value.Count:" + value.Count);

        if (sink.TryPopOutputBuffer(out ic4.ImageBuffer buffer)&& save_num< value.Count)
        {

            try
            {
                string zoomingValue = value[save_num].ToString();
                Console.WriteLine("zoomingValue：" + zoomingValue);
                Process.Start(motorFilePath, zoomingValue);
                Console.WriteLine("----start----");
                Thread.Sleep(30);
                Console.WriteLine("----stop----");
                buffer.SaveAsPng($"{file_name}/{save_num}.png");
                Console.WriteLine($"Saved image {$"{file_name}/{save_num}.png"}");
                display1.DisplayBuffer(buffer);
                //AnalyseMTFLeft(save_num);

            }
            catch (IC4Exception err)
            {
                Console.WriteLine($"Failed to save buffer: {err.Message}");
            }
            finally
            {
                buffer.Dispose();
            }
            save_num++;
        }

    };
    Console.WriteLine("22222");
    // Start the stream
    grabber2.StreamSetup(sink, StreamSetupOption.AcquisitionStart);
    //this.grabberL = grabber2;
    Console.WriteLine("333333");
}```

In the code 'Process.Start(motorFilePath, zoomingValue);' means adjust camera's focal length, The result is very strange, the first time it take photos, the image taken is the same as focusing before，do you why hanppened this, thank you so much for giving me so many recommendations.

[TIS-Tim]

You do realize that *PopOutputBuffer does not really synchronize to the camera? So you controlling some external motor depending on that function returning will not magically delay the next image being taken, and most images you receive are older than your motor movement. Additionally, are you sure that the external application is really done after 30ms?

The correct way to take images at a specific time on application request is the software trigger function.

[Skullface9512]

what is software trigger function? I found https://www.theimagingsource.com/en-us/documentation/ic4dotnet/articles/grabbing-an-image.html using SnapSink.SnapSingle to grab the single image, can it meet my demand?

[TIS-Tim]

There currently is no simple example showing software trigger. But a complex one: EventExposureEnd

But you might get the gist of it (which is enable TriggerMode and execute TriggerSoftware, still using QueueSink).

SnapSingle grab an image from the free-running stream of images, which by definition always looks a little into the past.

[janeshuu]

Hi, I want to use two cameras to display the camera streams on different display at the same time, but now I found that I have to turn off one of the cameras for the other camera to work. How should I solve this problem?
The code is as follow:

 private void btnOpenLeft_Click(object sender, EventArgs e)
        {            
            var selectedDeviceInfoL = ic4.WinForms.Dialogs.ShowSelectDeviceDialog(this);
            if (selectedDeviceInfoL == null) { return; }
            this.selectedDeviceInfoL = selectedDeviceInfoL;
            Resources.CameraParameter.selectedDeviceInfoL = selectedDeviceInfoL;
            ic4.Grabber grabber = new Grabber();
            var selectedDeviceInfo2 = this.selectedDeviceInfoL;
            grabber.DeviceOpen(selectedDeviceInfo2);
            Console.WriteLine($"Opened device {grabber.DeviceInfo.ModelName}");

            var sink = new ic4.QueueSink(ic4.PixelFormat.BGR8, maxOutputBuffers: 1);
            sink.FramesQueued += (s, args) =>
            {
                using (var buffer = sink.PopOutputBuffer())
                {
                    var wrap = buffer.CreateOpenCvWrap();

                    this.width = wrap.Width;
                    this.height = wrap.Height;


                    OpenCvSharp.Point startPoint1 = new OpenCvSharp.Point(Convert.ToInt32(width / 2) - 500, Convert.ToInt32(height / 2));
                    OpenCvSharp.Point endPoint1 = new OpenCvSharp.Point(Convert.ToInt32(width / 2) + 500, Convert.ToInt32(height / 2));
                    OpenCvSharp.Point startPoint2 = new OpenCvSharp.Point(Convert.ToInt32(width / 2), Convert.ToInt32(height / 2) - 500);
                    OpenCvSharp.Point endPoint2 = new OpenCvSharp.Point(Convert.ToInt32(width / 2), Convert.ToInt32(height / 2) + 500);

                    Cv2.Line(wrap, startPoint1, endPoint1, color, thickness);
                    Cv2.Line(wrap, startPoint2, endPoint2, color, thickness);

                    display1.DisplayBuffer(buffer);
                }
            };

            grabber.StreamSetup(sink, StreamSetupOption.AcquisitionStart);
            this.grabberL = grabber;
}
        private void btnOpenRight_Click(object sender, EventArgs e)
        {            
            var selectedDeviceInfoR = ic4.WinForms.Dialogs.ShowSelectDeviceDialog(this);
            if (selectedDeviceInfoR == null) { return; }
            this.selectedDeviceInfoR = selectedDeviceInfoR;
            Resources.CameraParameter.selectedDeviceInfoR = selectedDeviceInfoR;
            ic4.Grabber grabber = new Grabber();
            var selectedDeviceInfo2 = this.selectedDeviceInfoR;
            grabber.DeviceOpen(selectedDeviceInfo2);
            Console.WriteLine($"Opened device {grabber.DeviceInfo.ModelName}");

            var sink = new ic4.QueueSink(ic4.PixelFormat.BGR8, maxOutputBuffers: 1);
            sink.FramesQueued += (s, args) =>
            {
                using (var buffer = sink.PopOutputBuffer())
                {
                    var wrap = buffer.CreateOpenCvWrap();

                    this.width = wrap.Width;
                    this.height = wrap.Height;


                    OpenCvSharp.Point startPoint1 = new OpenCvSharp.Point(Convert.ToInt32(width / 2) - 500, Convert.ToInt32(height / 2)); 
                    OpenCvSharp.Point endPoint1 = new OpenCvSharp.Point(Convert.ToInt32(width / 2) + 500, Convert.ToInt32(height / 2));  
                    OpenCvSharp.Point startPoint2 = new OpenCvSharp.Point(Convert.ToInt32(width / 2), Convert.ToInt32(height / 2) - 500);
                    OpenCvSharp.Point endPoint2 = new OpenCvSharp.Point(Convert.ToInt32(width / 2), Convert.ToInt32(height / 2) + 500);

                    Cv2.Line(wrap, startPoint1, endPoint1, color, thickness);
                    Cv2.Line(wrap, startPoint2, endPoint2, color, thickness);
                    display2.DisplayBuffer(buffer);
                }
            };

            grabber.StreamSetup(sink, StreamSetupOption.AcquisitionStart);
            this.grabberR = grabber;
}

[TIS-Tim]

Which cameras are you using?
Do the two cameras work at the same time with the same settings in 2 instances of ic4-demoapp?

If you operate two cameras on the same network adapter or USB controllers, you have to take bandwidth into consideration. Set AcquisitionFrameRate to half the maximum for both cameras if you only have one interface.

[janeshuu]

Two cameras both named DFM 37UX178-ML
Where can I set AcquisitionFrameRate?

[TIS-Tim]

Please have a look at the documentation: Configuring a Video Capture Device

(It does not explicitly set AcquisitionFrameRate, but you should get the idea.)

[janeshuu]

It worked, thank you.
By the way, is there an interface to obtain the maximum frame rate? I can only check it through IC capture2.5 software

[TIS-Tim]

The documentation describes how to access and query information about the different types of device properties.

(You could also use the device property dialog in ic4-demoapp instead of IC Capture.)