使用 AForge c# 进行对象检测

Question

我正在尝试使用 AForge.NET 在 C# windows 窗体项目中创建对象检测。

我写了这段代码：

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;
}

结果总是黑色照片，我不知道为什么。 我用这张照片来尝试代码：

但仍会收到一张黑色照片。 有什么帮助吗？为什么是这样？ 如果你能告诉我如何检测图像中的所有对象。

Answer 1

你没有在 ToPointsArray 中做任何事情。你只是返回一个相同长度的数组。

你应该这样做（我不知道 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;
}

此外，您正在破坏您的 for 循环中的图像。此代码有效：

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);
}

我明白了以下几点：

(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)

因此，BlobCounter 似乎没有找到您要查找的 blob。