CODEWITHSUNDEEP
c#aforge
Samy Sammour
Samy Sammour

Reputation: 2465

Object Detection using AForge c#

I am trying to create object detection in C# windows form Project using AForge.NET.

I wrote this code: 

public void DetectCorners()
{
    // Load image and create everything you need for drawing
    Bitmap image = new Bitmap(@"C:\Users\ssammour\Desktop\Unbenannt.PNG");
    originalPicture.ImageLocation = @"C:\Users\ssammour\Desktop\Unbenannt.PNG";
    BlobCounter blobCounter = new BlobCounter();
    blobCounter.ProcessImage(image);
    Graphics g = this.CreateGraphics();
    Blob[] blobs = blobCounter.GetObjectsInformation();
    SimpleShapeChecker shapeChecker = new SimpleShapeChecker();
    Pen redPen = new Pen(Color.Red);
    for (int i = 0, n = blobs.Length; i < n; i++)
    {
        List<IntPoint> corners;
        List<IntPoint> edgePoints = blobCounter.GetBlobsEdgePoints(blobs[i]);

        if (shapeChecker.IsQuadrilateral(edgePoints, out corners))
        {
            g.DrawPolygon(redPen, ToPointsArray(corners));
            image = new Bitmap(image.Width, image.Height, g);
        }
    }

    // Display
    newPicture.Image = image;
}

private System.Drawing.Point[] ToPointsArray(List<IntPoint> points)
{
    System.Drawing.Point[] array = new System.Drawing.Point[points.Count];
    return array;
}

the result is always Black photo, I don't know why. I used this photo to try the code: enter image description here

but still receive a black photo. any help? and why is that? and if you please can tell me how can I detect all objects inside the image.

Upvotes: 0

Views: 3189

Answers (1)

Palle Due
Palle Due

Reputation: 6292

You are not doing anything in ToPointsArray. You are just returning an array of the same length.

You should do something like this instead (I don't know IntPoint):

private System.Drawing.Point[] ToPointsArray(List<IntPoint> points)
{
    System.Drawing.Point[] array = new System.Drawing.Point[points.Count];
    int i = 0;
    foreach (IntPoint p in points)
    {
        array[i++] = new System.Drawing.Point(p.X, p.Y);
    }
    return array;
}

Furthermore you are ruining your image in your for loop. This code works:

public void DetectCorners()
{
    // Load image and create everything you need for drawing
    Bitmap image = new Bitmap(@"C:\Users\ssammour\Desktop\Unbenannt.PNG");
    BlobCounter blobCounter = new BlobCounter();
    blobCounter.ProcessImage(image);
    Bitmap result = new Bitmap(image.Width, image.Height, Graphics.FromImage(image));
    Graphics g = Graphics.FromImage(result);
    g.DrawImage(image,0,0);
    Blob[] blobs = blobCounter.GetObjectsInformation();
    SimpleShapeChecker shapeChecker = new SimpleShapeChecker();
    Pen redPen = new Pen(Color.Red);
    for (int i = 0, n = blobs.Length; i < n; i++)
    {
        List<IntPoint> corners;
        List<IntPoint> edgePoints = blobCounter.GetBlobsEdgePoints(blobs[i]);

        if (shapeChecker.IsQuadrilateral(edgePoints, out corners))
        {
            corners.Dump();
            g.DrawPolygon(redPen, ToPointsArray(corners, image.Height));
        }
    }
    result.Save(@"c:\result.png", ImageFormat.Png);
}

I get these points:

(0 0),(574 0),(574 398),(0 398)

(161 391),(162 390),(165 393),(165 394)

(301 394),(304 392),(310 398),(303 398)

(552 398),(558 392),(561 392),(562 398)

(155 397),(156 396),(157 398),(155 398)

So, it looks like the BlobCounter doesn't find the blobs you are looking for.

Upvotes: 4

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