add generating result image to Results directory

Azaion.Common/Services/GalleryService.cs

@@ -265,6 +265,24 @@ public class GalleryService(
             logger.LogError(e, e.Message);
         }
     }
+
+    public async Task CreateAnnotatedImage(Annotation annotation, CancellationToken token)
+    {
+        var originalImage = Image.FromStream(new MemoryStream(await File.ReadAllBytesAsync(annotation.ImagePath, token)));
+
+        using var g = Graphics.FromImage(originalImage);
+        foreach (var detection in annotation.Detections)
+        {
+            var detClass = _annotationConfig.DetectionClassesDict[detection.ClassNumber];
+            var color = detClass.Color;
+            var brush = new SolidBrush(Color.FromArgb(color.A, color.R, color.G, color.B));
+            var det = new CanvasLabel(detection, new Size(originalImage.Width, originalImage.Height));
+            g.DrawRectangle(new Pen(brush, width: 3), (float)det.X, (float)det.Y, (float)det.Width, (float)det.Height);
+            var label  = detection.Confidence >= 0.995 ? detClass.UIName : $"{detClass.UIName}: {detection.Confidence * 100:F0}%";
+            g.DrawString(label, new Font(FontFamily.GenericSerif, 14), brush, new PointF((float)(det.X + det.Width / 2.0), (float)det.Y));
+        }
+        originalImage.Save(Path.Combine(_dirConfig.ResultsDirectory, $"{annotation.Name}{Constants.RESULT_PREFIX}.jpg"), ImageFormat.Jpeg);
+    }
 }
 
 public interface IGalleryService
@@ -275,4 +293,5 @@ public interface IGalleryService
     Task RefreshThumbnails();
     Task ClearThumbnails(CancellationToken cancellationToken = default);
 
+    Task CreateAnnotatedImage(Annotation annotation, CancellationToken token);
 }