OpenCVForUnity实现摄像头实时霍夫圆检测

Question

我在做一个摄像头可以识别圆形的东西
根据一个博主写的人脸检测修改后，摄像头打开只显示灰色，如下，无法识别圆形，请问怎么解决这些问题？

Console如下：

文章：https://blog.csdn.net/GottaYiWanLiu/article/details/90442274

步骤如下：
第一步先导入OpenCVForUnity，给quad附加例子中的WebCamTextureToMatExample；

第二步将CircleDetect脚本附加给quad，检测圆形代码如下：

using OpenCVForUnity.CoreModule;
using OpenCVForUnity.ImgprocModule;
using OpenCVForUnity.Structured_lightModule;
using OpenCVForUnity.UnityUtils;
using OpenCVForUnity;
using OpenCVForUnityExample;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class CircleDetect : MonoBehaviour
{
  
    
    WebCamTextureToMatExample webcamTexToMat = new WebCamTextureToMatExample();
    Mat gray;
    Texture2D texture;
    
    public void Start()
    {
        
        
        webcamTexToMat = transform.GetComponent<WebCamTextureToMatExample>();
        Mat gray = new Mat();

        //texture = new Texture2D(640, 480);
        //GetComponent<Renderer>().material.mainTexture = texture;

        
    }
    public void ProcessImage()
    {
        //webcamTexToMat = transform.GetComponent<WebCamTextureToMatExample>();
        //Mat gray = new Mat();

        //texture = new Texture2D(640, 480);
        //GetComponent<Renderer>().material.mainTexture = texture;

        // 转换为灰度图像

        Imgproc.cvtColor(webcamTexToMat.rgbaMat, gray, Imgproc.COLOR_RGBA2GRAY);


        // 高斯模糊
        Imgproc.GaussianBlur(gray, gray, new Size(9, 9), 2, 2);


        // 检测圆形
        Mat circles = new Mat();
        Imgproc.HoughCircles(gray, circles, Imgproc.HOUGH_GRADIENT, 1,10, 200, 100, 0, 0);


        // 绘制检测到的圆形
        for (int i = 0; i < circles.cols(); i++)
        {
            double[] circleData = circles.get(0, i);
            Point center = new Point(circleData[0], circleData[1]);
            int radius = (int)circleData[2];
            Imgproc.circle(webcamTexToMat.rgbaMat, center, radius, new Scalar(255, 0, 0), 5);
        }


        // 显示结果
        //Utils.matToTexture2D(webcamTexToMat.rgbaMat, texture);

    }
    

}

第三步根据博主修改WebCamTextureToMatExample中的一部分代码如图

Answer 1

using UnityEngine;
using UnityEngine.UI;
using OpenCVForUnity.CoreModule;
using OpenCVForUnity.ImgprocModule;
using OpenCVForUnity.UnityUtils;
using OpenCVForUnity.VideoioModule;
using OpenCVForUnityExample;

public class CircleDetection : MonoBehaviour
{
    public RawImage rawImage;

    private WebCamTexture webCamTexture;
    private Mat rgbaMat;
    private Texture2D texture;

    void Start()
    {
        webCamTexture = new WebCamTexture();
        webCamTexture.Play();

        rgbaMat = new Mat(webCamTexture.height, webCamTexture.width, CvType.CV_8UC4);
        texture = new Texture2D(webCamTexture.width, webCamTexture.height, TextureFormat.RGBA32, false);

        rawImage.texture = texture;
    }

    void Update()
    {
        if (webCamTexture.didUpdateThisFrame)
        {
            Utils.webCamTextureToMat(webCamTexture, rgbaMat);

            Mat grayMat = new Mat();
            Imgproc.cvtColor(rgbaMat, grayMat, Imgproc.COLOR_RGBA2GRAY);
            Imgproc.GaussianBlur(grayMat, grayMat, new Size(9, 9), 2, 2);

            Mat circles = new Mat();
            Imgproc.HoughCircles(grayMat, circles, Imgproc.HOUGH_GRADIENT, 1, grayMat.rows() / 8, 100, 20, 0, 0);

            for (int i = 0; i < circles.cols(); i++)
            {
                double[] circle = circles.get(0, i);
                if (circle == null) break;

                Point center = new Point(circle[0], circle[1]);
                int radius = (int)circle[2];
                Imgproc.circle(rgbaMat, center, radius, new Scalar(255, 0, 0, 255), 3);
            }

            Utils.fastMatToTexture2D(rgbaMat, texture);
        }
    }

    void OnDestroy()
    {
        if (webCamTexture != null)
        {
            webCamTexture.Stop();
        }
        if (rgbaMat != null)
        {
            rgbaMat.Dispose();
        }
    }
}