yolov7-tiny的c# 调用，vs2022使用opencvsharp推理。

最近AB大神yolov7出来了，我们使用c# 调用yolov7-tiny，使用openchsharp加载.weights 和.cfg文件，进行推理。i5 10400 的 total时间 在25ms左右。还是很快的。跟yolov4一样，对于opencv很友好。yolov4-tiny 也在25ms左右，c#调用代码都通用。

首先在nuget程序包里搜索，opencvsharp

完整demo程序下载

yolov7-tiny的c#调用，vs2022使用opencvsharp推理-C#文档类资源-CSDN文库https://download.csdn.net/download/vokxchh/85993605

 其中调用代码如下。

using OpenCvSharp;
using OpenCvSharp.Dnn;
using System.Diagnostics;
using System.Drawing.Drawing2D;

namespace WinFormsApp5
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        private const string configurationFilename = @".\Cfg\yolov7-tiny.cfg";
        private const string weightsFilename = @".\Weights\yolov7-tiny_last.weights";
        private const string namesFile = @".\Data\vocTR.names";
        private static Dictionary _namesDic = new Dictionary();
        Net? net;
        const float threshold = 0.5f;    
        const float nmsThreshold = 0.3f;   
        static BoundingBox[] bbox = new BoundingBox[1000];
        /// 

        /// 画图
        /// 
        public static Bitmap? DrawRectangleInPicture(Bitmap bmp, int id, float prob, int x, int y, int width, int height, Color RectColor, int LineWidth, DashStyle ds)
        {
            try
            {
                if (bmp == null) return null;

                Graphics g = Graphics.FromImage(bmp);

                Brush brush = new SolidBrush(RectColor);
                Pen pen = new Pen(brush, LineWidth);
                pen.DashStyle = ds;
                SolidBrush drawBush = new SolidBrush(Color.Red);
                Font drawFont = new Font("Arial", 12, FontStyle.Bold, GraphicsUnit.Millimeter);
                g.DrawString(_namesDic[(int)id] + " " + prob.ToString("F2"), drawFont, drawBush, 1, 1);
                var x1 = (x - width / 2) < 0 ? 0 : x - width / 2; //avoid left side over edge
                var y1 = (y - height / 2) < 0 ? 0 : y - height / 2; //avoid left side over edge
                Rectangle rect = new Rectangle(x1, y1, width, height);
          
                g.DrawRectangle(pen, rect);
                System.Drawing.Color Mycolor = System.Drawing.Color.FromArgb(60, Color.Yellow);//透明度1-255
                System.Drawing.SolidBrush SB1 = new System.Drawing.SolidBrush(Mycolor);
                g.FillRectangle(SB1, rect);
                g.Dispose();

                return bmp;
            }
            catch (Exception ) { return null; }
        }
        /// 

        /// 获取yolov7输出
        /// 
        private static void GetResult(IEnumerable output, Mat image, float threshold, float nmsThreshold, bool nms = true)
        {
            Array.Clear(bbox, 0, 1000);
        
            var classIds = new List();
            var confidences = new List();
            var probabilities = new List();
            var boxes = new List();
            var w = image.Width;
            var h = image.Height;
        
            const int prefix = 5;  
            foreach (var prob in output)
            {
                for (var i = 0; i < prob.Rows; i++)
                {
                    var confidence = prob.At(i, 4);
                    if (confidence > threshold)
                    {
                      
                        Cv2.MinMaxLoc(prob.Row(i).ColRange(prefix, prob.Cols), out _, out OpenCvSharp.Point max);
                        var classes = max.X;
                        var probability = prob.At(i, classes + prefix);
                        if (probability > threshold) 
                        {
                          
                            var centerX = prob.At(i, 0) * w;
                            var centerY = prob.At(i, 1) * h;
                            var width = prob.At(i, 2) * w;
                            var height = prob.At(i, 3) * h;
                            if (!nms)
                            {
                               
                                continue;
                            }
                        
                            classIds.Add(classes);
                            confidences.Add(confidence);
                            probabilities.Add(probability);
                            boxes.Add(new Rect2d(centerX, centerY, width, height));
                        }
                    }
                }
            }
            if (!nms) return;
           
            CvDnn.NMSBoxes(boxes, confidences, threshold, nmsThreshold, out int[] indices);
         
            foreach (var i in indices)
            {
                var box = boxes[i];
                if (box.X >= 0 && box.Y >= 0)
                {
                    bbox[i].w = box.Width; bbox[i].x = box.X; bbox[i].y = box.Y; bbox[i].h = box.Height;
                    bbox[i].prob = probabilities[i];
                    bbox[i].obj_id = classIds[i];
                }
            }
        }
        public struct BoundingBox
        {
            public double x, y, w, h;
            public float prob;
            public Int32 obj_id;
        }
        /// 

        /// 检测
        /// 
        void detectR(string filename)
        {
            try
            {


                Stopwatch swR = new Stopwatch();
                swR.Start();

                Bitmap img =(Bitmap) Image.FromFile(filename);
                var org = OpenCvSharp.Extensions.BitmapConverter.ToMat(img);
                var blob = CvDnn.BlobFromImage(org, 1.0 / 255, new OpenCvSharp.Size(416, 416), new Scalar(), true, false);
                net.SetInput(blob);
                var outNames = net.GetUnconnectedOutLayersNames();
                var outs = outNames.Select(_ => new Mat()).ToArray();
                net.Forward(outs, outNames);
                GetResult(outs, org, threshold, nmsThreshold);
                swR.Stop();
                string TotalTime = swR.ElapsedMilliseconds.ToString();  //i5 10400 25ms
               
                if (bbox != null)
                {
                    foreach (var i in bbox)
                    {
                        if (i.prob >= 0.70 && i.w <= 100)
                        {
                            DrawRectangleInPicture(img, (int)i.obj_id, i.prob, (int)i.x, (int)i.y, (int)i.w, (int)i.h, Color.Red, 3, DashStyle.Solid);
                          
                        }
                    }

                }
                pictureBox1.BeginInvoke(new MethodInvoker(delegate () { pictureBox1.Image = img; }));
                label1.BeginInvoke(new MethodInvoker(delegate () { label1.Text = TotalTime+" ms"; }));
            }
            catch (Exception ex) { MessageBox.Show(ex.Message.ToString()); }
        }
        private void Initilize()
        {
            try
            {
                net = CvDnn.ReadNetFromDarknet(configurationFilename, weightsFilename);
          
                net.SetPreferableBackend((Backend)3);
                net.SetPreferableTarget(0);
                var lines = File.ReadAllLines(namesFile);
                for (var i = 0; i < lines.Length; i++)
                    _namesDic.Add(i, lines[i]);
            }
            catch (Exception ex) { MessageBox.Show( ex.Message.ToString()); }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            pictureBox1.Image = null;
            detectR("1.jpg");


        }

        private void Form1_Load(object sender, EventArgs e)
        {
            Initilize();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            pictureBox1.Image = null;
            detectR("2.jpg");

        }
    }
}

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原始80分类权重demo程序下载

yolov7darknet80分类原始权重的C#调用，使用opencvsharp载入weight和cfg文件。-C#文档类资源-CSDN文库