rom fastapi import FastAPI, Depends, HTTPException from cache import cache, cached import asyncio app = FastAPI(title=“FastAPI Redis缓存演示”) # 应用启动和关闭事件 async def startup_event (): await cache.connect() print (“✅ Redis connected”) async def shutdown_event (): await cache.disconnect() print (“👋 Redis disconnected”) # --- 模拟一个耗时的数据查询函数 --- async def fetch_user_data_from_db ( user_id: int ): """模拟从数据库查询用户数据（耗时操作）""" await asyncio.sleep( 2 ) # 模拟2秒的IO延迟 return {“ id ”: user_id, “name”: f“用户_{user_id}”, “score”: user_id * 10 } # --- 应用缓存的接口 --- # 为此接口单独设置30秒缓存 async def get_user ( user_id: int ): """获取用户信息（带缓存）""" data = await fetch_user_data_from_db(user_id) return {“source”: “database (cached later)”, “data”: data} async def get_user_fresh ( user_id: int ): """获取用户信息（强制查数据库，不缓存）""" data = await fetch_user_data_from_db(user_id) return {“source”: “database (fresh)”, “data”: data} async def delete_user_cache ( user_id: int ): """手动删除某个用户的缓存""" # 注意：这里需要模拟生成和接口一致的缓存键，实战中可能需要更复杂的键管理 key_pattern = f“fastapi_cache:get_user:{user_id}” deleted = await cache.delete(key_pattern) if deleted: return {“message”: f”Cache for user {user_id} deleted.”} raise HTTPException(status_code= 404 , detail=“Cache key not found”) if __name__ == “__main__”: import uvicorn
{if (!File.Exists(imagePath))
{
Console.WriteLine("文件不存在!");
Console.ReadKey();return;
}try
{
Console.WriteLine($"处理:m.114dhz.cn {Path.GetFileName(imagePath)}");var stopwatch = Stopwatch.StartNew();// 检测面单var results = _detector.DetectLabels(imagePath);
stopwatch.Stop();
Console.WriteLine($"检测耗时: {stopwatch.ElapsedMilliseconds}ms");
Console.WriteLine($"找到 {results.Count} 个面单区域");if (results.Count == 0)
{
Console.WriteLine("未检测到面单!");
Console.ReadKey();njsydq.cnreturn;
}// 显示结果foreach (var result in results)
{
Console.WriteLine($"- {result.DetectionMethod}: 置信度 {result.Confidence:F2}, " +$"位置 [{result.BoundingBox.X}, {result.BoundingBox.Y}, " +$"{result.BoundingBox.Width}, {result.BoundingBox.Height}]");
}// 创建输出目录var outputDir = _config.OutputDirectory;if (!Directory.Exists(outputDir))
Directory.CreateDirectory(outputDir);var baseName = Path.GetFileNameWithoutExtension(imagePath);// 保存可视化结果if (_config.SaveVisualized)
{using (var original = new Bitmap(imagePath))
{
Bitmap bitResult = ImageProcessor.DrawBoundingBoxesSafe(original, results);var visPath = Path.Combine(outputDir, $"{baseName}_detected.png");
ImageProcessor.SaveImage(bitResult, visPath);
Console.WriteLine($"可视化结果已保存: {visPath}");
}
}// 保存抠图结果 if (_config.SaveCropped)
{using (var mat = Cv2.ImRead(imagePath))
{for (int i = 0; i < results.Count; i++)
{var cropped = _detector.CropLabel(mat, results[i].BoundingBox);if (cropped != null)
{// 图像增强
_detector.EnhanceImage(ref cropped);var cropPath = Path.Combine(outputDir, $"{baseName}_label_{i + 1}.png");
Console.WriteLine(cropped);
ImageProcessor.SaveImage(cropped, cropPath);
Console.WriteLine($"抠图已保存: {cropPath}");
cropped.Dispose();
}
}
}
}// 保存检测结果到JSON
SaveResultsToJson(results, Path.Combine(outputDir, $"{baseName}_results.json"));
Console.WriteLine("\n处理完成! 按任意键继续...");
}catch (Exception ex)
{
Console.WriteLine($"处理失败: {ex.Message}");
}
public List<DetectionResult> DetectLabels(string imagePath)
{var results = new List<DetectionResult>();using (var mat = Cv2.ImRead(imagePath, OpenCvSharp.ImreadModes.Color))
{if (mat.Empty())
thrownew FileNotFoundException($"无法加载图像: {imagePath}");// 方法1: 轮廓检测var contourResults = DetectByContours(mat);
results.AddRange(contourResults)wap.jrwsh.com;// 方法2: 颜色检测var colorResults = DetectByColor(mat);
results.AddRange(colorResults);// 方法3: 边缘检测var edgeResults = DetectByEdges(mat);
results.AddRange(edgeResults);
{var results = new List<DetectionResult>();
using (var gray = new OpenCvSharp.Mat())using (var binary = new OpenCvSharp.Mat())
{
Cv2.CvtColor(src, gray, ColorConversionCodes.BGR2GRAY);// 二值化
Cv2.Threshold(gray, binary, 0, 255, ThresholdTypes.Binary | ThresholdTypes.Otsu);// 形态学操作var kernel = Cv2.GetStructuringElement(MorphShapes.Rect, new OpenCvSharp.Size(3, 3));
Cv2.MorphologyEx(binary, binary, MorphTypes.Close, kernel);// 查找轮廓 Cv2.FindContours(binary, outvar contours, outvar hierarchy,
RetrievalModes.External, ContourApproximationModes.ApproxSimple);foreach (var contour in contours)
{var area =hnsgzxh.com Cv2.ContourArea(contour);
if (area < _minArea || area > _maxArea)continue;
Console.WriteLine($"面积：{area}");var rect = Cv2.BoundingRect(contour);// 计算宽高比var aspectRatio = (double)rect.Width / rect.Height;// 面单通常为矩形，宽高比在一定范围内if (aspectRatio > 0.5 && aspectRatio < 3.0)
{// 计算矩形度var rectArea = rect.Width * rect.Height;var rectangularity = area / rectArea;
Console.WriteLine(rectangularity) weajoy.com;if (rectangularity > 0.55)
{
results.Add(new DetectionResult
{
BoundingBox = rect.ToRectangle(),
Confidence = rectangularity,
DetectionMethod = "Contour"
});
private List<DetectionResult> DetectByColor(OpenCvSharp.Mat src)
{var results = new List<DetectionResult>();using (var hsv = new OpenCvSharp.Mat())using (var mask = new OpenCvSharp.Mat())
{// 转换到HSV色彩空间 Cv2.CvtColor(src, hsv, ColorConversionCodes.BGR2HSV);// 定义白色/浅色范围var lowerWhite1 = new Scalar(0, 0, 200);var upperWhite1 = new Scalar(180, 30, 255);var lowerWhite2 = new Scalar(0, 0, 180);var upperWhite2 = new Scalar(180, 80, 255);using (var mask1 = new OpenCvSharp.Mat())using (var mask2 = new OpenCvSharp.Mat())
{
Cv2.InRange(hsv, lowerWhite1, upperWhite1, mask1);
Cv2.InRange(hsv, lowerWhite2, upperWhite2, mask2);
Cv2.BitwiseOr(mask1, mask2, mask);
}// 形态学操作var kernel njsydq.cn= Cv2.GetStructuringElement(MorphShapes.Rect, new OpenCvSharp.Size(5, 5));
Cv2.MorphologyEx(mask, mask, MorphTypes.Close, kernel);
Cv2.MorphologyEx(mask, mask, MorphTypes.Open, kernel);// 查找轮廓 Cv2.FindContours(mask, outvar contours, outvar hierarchy,
RetrievalModes.External, ContourApproximationModes.ApproxSimple);foreach (var contour in contours)
{var area = Cv2.ContourArea(contour);if (area < _minArea || area > _maxArea)continue;var rect = Cv2.BoundingRect(contour);// 计算颜色均匀度var uniformity = CalculateColorUniformity(src, rect);if (uniformity > _confidenceThreshold)
{
results.Add(new DetectionResult
{
BoundingBox = rect.ToRectangle(),
Confidence = uniformity,
DetectionMethod = "Color"
});
}
}
}return results;
}3.边缘检测private List<DetectionResult> DetectByEdges(OpenCvSharp.Mat src)
{var results = new List<DetectionResult>();using (var gray = new OpenCvSharp.Mat())using (var edges = new OpenCvSharp.Mat())
{
Cv2.CvtColor(src, gray, ColorConversionCodes.BGR2GRAY);// 降噪
Cv2.GaussianBlur(gray, gray, new OpenCvSharp.Size(5, 5), 1.5);// 边缘检测
Cv2.Canny(gray, edges, 50, 150);// 膨胀var kernel = Cv2.GetStructuringElement(MorphShapes.Rect, new OpenCvSharp.Size(3, 3));
Cv2.Dilate(edges, edges, kernel, iterations: 2);// 查找轮廓 Cv2.FindContours(edges, outvar contours, outvar hierarchy,
RetrievalModes.External, ContourApproximationModes.ApproxSimple);foreach (var contour in contours)
{var area = Cv2.ContourArea(contour);if (area < _minArea || area > _maxArea)continue;var rect = Cv2.BoundingRect(contour);// 计算边缘密度using (var roi = new OpenCvSharp.Mat(edges, rect))
{var totalPixels =byven.com roi.Rows * roi.Cols;var edgePixels = Cv2.CountNonZero(roi);var edgeDensity = (double)edgePixels / totalPixels;if (edgeDensity > 0.1 && rect.Width > 100 && rect.Height > 100)
{
results.Add(new DetectionResult
{
BoundingBox = rect.ToRectangle(),
Confidence = edgeDensity,
// 返回面单图片///</summary>///<param name="errorMsg">异常信息</param>///<param name="IsEnhanceImage">面单是否增强</param>///<param name="IsSaveLocl">是否本地保存</param>///<returns></returns>public Bitmap GetLabelImageByBitmap(outstring errorMsg, bool IsEnhanceImage = true, bool IsSaveLocl = true)
{
Bitmap croppedImage fjzhongxiang.cn= null;
errorMsg = string.Empty; byven.com try
{ if (!File.Exists(imagePath))
{
ShellLine.WriteLine($"请确保 {imagePath} 存在");
errorMsg = $"请确保 {imagePath} 存在";
returnnew Bitmap(10, 10);
} //图片目录
string imageDir = Path.GetDirectoryName(debugImagePath); if (Directory.Exists(imageDir))
{
Directory.CreateDirectory(imageDir);
}
Bitmap bitmap1 Lyyqhb.cn= new Bitmap(imagePath); var rr = oCR.GetOCRDataStr(bitmap1, debugImagePath); // 读取JSON文件
string jsonFilePath = imageDir + "\\content.json"; if (!File.Exists(jsonFilePath))
{
errorMsg = $"未找到JSON文件，请确保 {jsonFilePath} 存在";
ShellLine.WriteLine($"未找到JSON文件，请确保 {jsonFilePath} 存在");
returnnew Bitmap(imagePath);
} string preRotatedImage Lyyqhb.cn= imageDir + "\\preRotatedImg.jpg"; if (!File.Exists(preRotatedImage))
{
errorMsg = $"未找到面单文件，请确保包裹面单清晰且存在";
ShellLine.WriteLine($"未找到面单文件，请确保包裹面单清晰且存在");
returnnew Bitmap(imagePath);
} // 解析矩形数据并计算最小外接矩形
List<Rectangle> rectangles = ParseRectanglesFromJson(jsonFilePath); if (rectangles.Count == 0)
{
errorMsg = "未在JSON文件中找到有效的矩形数据";
ShellLine.WriteLine("未在JSON文件中找到有效的矩形数据");
returnnew Bitmap(imagePath);
}
Rectangle boundingRect = CalculateBoundingRectangle(rectangles);
ShellLine.WriteLine($"最小外接矩形: X={boundingRect.X}, Y={boundingRect.Y}, Width={boundingRect.Width}, Height={boundingRect.Height}");
ShellLine.WriteLine($"包含 {rectangles.Count} 个元素"); // 加载图片并进行裁剪
using (Bitmap originalImage = new Bitmap(preRotatedImage))
{ // 确保矩形在图片范围内
Rectangle safeRect = GetSafeRectangle(boundingRect, originalImage); // 裁剪图片
croppedImage jntmjq.cn= CropImage(originalImage, safeRect); if (IsEnhanceImage)
{ // 增强显示
EnhanceImage(ref croppedImage);
} if (IsSaveLocl)
{ // 保存结果
string outputPath = Path.Combine(
Path.GetDirectoryName(preRotatedImage),
Path.GetFileNameWithoutExtension(preRotatedImage) + "_cropped_enhanced.jpg");
croppedImage.Save(outputPath, ImageFormat.Jpeg);
ShellLine.WriteLine($"处理完成！结果已保存到: {outputPath}");
} // 显示裁剪区域信息
ShellLine.WriteLine($"\n裁剪区域信息:");
ShellLine.WriteLine($" 原始图片尺寸: {originalImage.Width}x{originalImage.Height}");
ShellLine.WriteLine($" 裁剪区域: {safeRect.X}, {safeRect.Y}, {safeRect.Width}x{safeRect.Height}");
ShellLine.WriteLine($" 增强后图片尺寸: {croppedImage.Width}x{croppedImage.Height}"); return croppedImage;
}
} catch (Exception ex)
{
errorMsg = $"处理过程中出现错误: {ex.Message}";
ShellLine.WriteLine($"处理过程中出现错误: {ex.Message}");
ShellLine.WriteLine($"堆栈跟踪: {ex.StackTrace}");
returnnew Bitmap(imagePath);
}
publicvoidEnhanceImage(ref Bitmap image)
{ using (var mat = image.ToMat()) using (var lab = new OpenCvSharp.Mat())
{ // 转换为Lab色彩空间 Cv2.CvtColor(mat, lab, ColorConversionCodes.BGR2Lab);
Cv2.Split(lab, outvar labChannels); // 对亮度通道进行直方图均衡化
Cv2.EqualizeHist(labChannels[0], labChannels[0]);
Cv2.Merge(labChannels,jntmjq.cn lab);
Cv2.CvtColor(lab, mat, ColorConversionCodes.Lab2BGR); // 释放通道
foreach (var channel in labChannels)
channel.Dispose(); // 更新图像
static Rectangle CalculateBoundingRectangle(List<Rectangle> rectangles)
{ if (rectangles.Count == 0)
thrownew ArgumentException("矩形列表为空"); int minX = int.MaxValue; int minY = int.MaxValue; int maxX = int.MinValue; int maxY = int.MinValue; foreach (Rectangle rect in rectangles)
{
minX yfiso9000.com= Math.Min(minX, rect.X);
minY = Math.Min(minY, rect.Y);
maxX = Math.Max(maxX, rect.X + rect.Width);
maxY = Math.Max(maxY, rect.Y + rect.Height);
} // 添加一些边距，使裁剪更美观
int margin = 10;
minX = Math.Max(0, minX - margin);
minY = Math.Max(0, minY - margin);
maxX = maxX + margin;
maxY = maxY + margin;
returnnew Rectangle(minX, minY, maxX - minX, maxY - minY);
}// 确保矩形在图片范围内static Rectangle GetSafeRectangle(Rectangle rect, Bitmap image)
{ int x yfiso9000.com=jntmjq.cn Math.Max(0, Math.Min(rect.X, image.Width - 1)); int y = Math.Max(0, Math.Min(rect.Y, image.Height - 1)); int width = Math.Min(rect.Width, image.Width - x); int height = Math.Min(rect.Height, image.Height - y);
returnnew Rectangle(x, y, width, height);
}// 裁剪图片static Bitmap CropImage(Bitmap source, Rectangle cropArea)
{
Bitmap target = new Bitmap(cropArea.Width, cropArea.Height); using (Graphics g = Graphics.FromImage(target))
{
g.DrawImage(source, new Rectangle(0, 0, cropArea.Width, cropArea.Height),
cropArea, GraphicsUnit.Pixel);
}
来自 “ ITPUB博客 ” ，链接：https://blog.itpub.net/70048957/viewspace-3109181/ ，如需转载，请注明出处，否则将追究法律责任。
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