這里是一個簡單的比較Python和C#中的YOLO實現的例子:
Python版本:
import cv2
net = cv2.dnn.readNet("yolov3.weights", "yolov3.cfg")
classes = []
with open("coco.names", "r") as f:
classes = [line.strip() for line in f.readlines()]
layer_names = net.getLayerNames()
output_layers = [layer_names[i[0] - 1] for i in net.getUnconnectedOutLayers()]
image = cv2.imread("image.jpg")
blob = cv2.dnn.blobFromImage(image, 0.00392, (416, 416), (0, 0, 0), True, crop=False)
net.setInput(blob)
outs = net.forward(output_layers)
for out in outs:
for detection in out:
scores = detection[5:]
class_id = np.argmax(scores)
confidence = scores[class_id]
if confidence > 0.5:
center_x = int(detection[0] * image.shape[1])
center_y = int(detection[1] * image.shape[0])
width = int(detection[2] * image.shape[1])
height = int(detection[3] * image.shape[0])
x = int(center_x - width / 2)
y = int(center_y - height / 2)
cv2.rectangle(image, (x, y), (x + width, y + height), (0, 255, 0), 2)
cv2.putText(image, classes[class_id], (x, y - 5), cv2.FONT_HERSHEY_SIMPLEX, 0.5, (0, 255, 0), 2)
cv2.imshow("Image", image)
cv2.waitKey(0)
cv2.destroyAllWindows()
C#版本:
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web;
using System.Web.Http;
public class YoloController : ApiController
{
[HttpPost]
public IHttpActionResult DetectObjects()
{
string modelFilePath = HttpContext.Current.Server.MapPath("~/yolov3.weights");
string configFilePath = HttpContext.Current.Server.MapPath("~/yolov3.cfg");
string classesFilePath = HttpContext.Current.Server.MapPath("~/coco.names");
var classes = File.ReadAllLines(classesFilePath);
var net = CvDnn.ReadNet(modelFilePath, configFilePath);
var layerNames = net.GetLayerNames();
var outputLayers = layerNames.Where(l => net.GetUnconnectedOutLayers().Contains(l)).ToList();
var image = HttpContext.Current.Request.Files["image"];
var bitmap = new Bitmap(image.InputStream);
var blob = CvDnn.BlobFromImage(bitmap, 0.00392, new Size(416, 416), new Scalar(0, 0, 0), true, false);
net.SetInput(blob);
var outs = net.Forward(outputLayers.ToArray());
foreach (var detection in outs)
{
var scores = detection.Skip(5);
var classId = Array.IndexOf(scores, scores.Max());
var confidence = scores[classId];
if (confidence > 0.5)
{
var centerX = (int)(detection[0] * bitmap.Width);
var centerY = (int)(detection[1] * bitmap.Height);
var width = (int)(detection[2] * bitmap.Width);
var height = (int)(detection[3] * bitmap.Height);
var x = centerX - width / 2;
var y = centerY - height / 2;
using (var graphics = Graphics.FromImage(bitmap))
{
graphics.DrawRectangle(Pens.Green, x, y, width, height);
graphics.DrawString(classes[classId], new Font("Arial", 12), Brushes.Green, new PointF(x, y - 15));
}
}
}
var outputStream = new MemoryStream();
bitmap.Save(outputStream, ImageFormat.Jpeg);
return Ok(Convert.ToBase64String(outputStream.ToArray()));
}
}
這兩個版本都使用了OpenCV的深度學習模塊來實現YOLO目標檢測算法。雖然Python和C#的代碼語法和結構有所不同,但它們的實現原理是相似的。在Python版本中,我們使用了cv2來讀取模型和圖像,并進行目標檢測的操作。而在C#版本中,我們使用了Emgu.CV庫來實現相同的功能。無論是Python還是C#,都可以很容