OpenCvSharp PCA 异常：不支持的输入和输出数组格式组合

Question

我正在使用 OpenCVSharp（OpenCvSharp3-AnyCPU 版本 3.0.0.20150823 运行在 Visual Studio 2015 中并通过 NuGet 安装）从 C# 访问 OpenCV，但是当调用 Cv2.PCACompute 我得到一个通用的 OpenCVException 说明我有一个 不支持的输入和输出数组格式组合 .

我的目标是使用 PCA 找到像素块的主轴。这是我目前的（精简）代码：

using OpenCvSharp;

public struct point2D
{
     public int X;
     public int Y;

     public point2D(int X, int Y)
     {
          this.X = X;
          this.Y = Y;
     }
}

public static void PCA2D()
{
    int height = 5;
    int width = 5;

    int[] image = new int[]
    {
         0,0,0,0,1,
         0,0,0,1,0,
         0,0,1,0,0,
         0,1,0,0,0,
         1,0,0,0,0,
    }

    // extract the datapoints
    List<point2D> dataPoints = new List<point2D>();

    for (int row = 0; row < height; ++row)
    {
         for (int col = 0; col < width; ++col)
         {
              if (image[row * width + col] == 1)
              {
                  dataPoints.Add(new point2D(col, row));
              }
         }
    }

    // create the input matrix
    Mat input = new Mat(dataPoints.Length, 2, MatType.CV_32SC1);

    for (int i = 0; i < dataPoints.Length; ++i)
    {
        input.Set(i, 0, dataPoints[i].X);
        input.Set(i, 1, dataPoints[i].Y);
    }

    Mat mean = new Mat();
    Mat eigenvectors = new Mat();

    // OpenCVException occurs here: unsupported combination of input and output array formats
    Cv2.PCACompute(input, mean, eigenvectors);

    // Code to get orientation from the eigenvectors
}

我无法找到任何关于如何初始化均值和特征向量垫的文档，或者我调用 PCACompute 的方式是否正确。深入了解使用 PCACompute 的正确过程将非常有帮助。

Answer 1

原来dataPoints不可能是MatType.CV_32SC1。将代码更改为以下允许它工作：

// create the input matrix
Mat input = new Mat(dataPoints.Length, 2, MatType.CV_32FC1);

for (int i = 0; i < dataPoints.Length; ++i)
{
    input.Set(i, 0, (float)dataPoints[i].X);
    input.Set(i, 1, (float)dataPoints[i].Y);
}

OpenCvSharp PCA 异常：不支持的输入和输出数组格式组合

OpenCvSharp PCA Exception: Unsupported combination of input and output array formats

c#

opencv

pca

opencvsharp