Add GPU validation and configuration support in NumberRecognitionEngine

src/AIFotoONLUS.Core/NumberRecognitionEngine.cs

@@ -106,6 +106,11 @@ namespace AIFotoONLUS.Core
             {
                 // Ignore if not supported by OpenCvSharp build
             }
+
+            if (_cfg.UseGpu)
+            {
+                ValidateGpuRuntime();
+            }
         }
 
         public void Dispose()
@@ -117,6 +122,38 @@ namespace AIFotoONLUS.Core
             GC.SuppressFinalize(this);
         }
 
+        public static bool TryValidateGpuRuntime(ModelConfiguration cfg, ILogger? logger, out string? failureMessage)
+        {
+            if (cfg is null) throw new ArgumentNullException(nameof(cfg));
+
+            var probeConfiguration = new ModelConfiguration
+            {
+                DetectionCfg = cfg.DetectionCfg,
+                DetectionWeights = cfg.DetectionWeights,
+                RecognitionCfg = cfg.RecognitionCfg,
+                RecognitionWeights = cfg.RecognitionWeights,
+                ConfidenceThreshold = cfg.ConfidenceThreshold,
+                NmsThreshold = cfg.NmsThreshold,
+                DetectionInputSize = cfg.DetectionInputSize,
+                RecognitionInputSize = cfg.RecognitionInputSize,
+                NumberClasses = cfg.NumberClasses,
+                EnableCropSaving = cfg.EnableCropSaving,
+                UseGpu = true
+            };
+
+            try
+            {
+                using var engine = new NumberRecognitionEngine(probeConfiguration, logger);
+                failureMessage = null;
+                return true;
+            }
+            catch (Exception ex)
+            {
+                failureMessage = ex.GetBaseException().Message;
+                return false;
+            }
+        }
+
         private static string SanitizeFileName(string name)
         {
             foreach (var c in Path.GetInvalidFileNameChars()) name = name.Replace(c, '_');
@@ -138,6 +175,26 @@ namespace AIFotoONLUS.Core
             net.SetPreferableTarget(Target.CPU);
         }
 
+        private void ValidateGpuRuntime()
+        {
+            try
+            {
+                using var detectionProbe = new Mat(_cfg.DetectionInputSize.Height, _cfg.DetectionInputSize.Width, MatType.CV_8UC3, Scalar.All(0));
+                _ = DetectTextRegions(_detectionNet, detectionProbe).Take(1).ToArray();
+
+                using var recognitionProbe = new Mat(_cfg.RecognitionInputSize.Height, _cfg.RecognitionInputSize.Width, MatType.CV_8UC3, Scalar.All(0));
+                using var blob = CvDnn.BlobFromImage(recognitionProbe, 0.00392, _cfg.RecognitionInputSize, new Scalar(0, 0, 0), true, false);
+                _recognitionNet.SetInput(blob);
+                using var output = _recognitionNet.Forward();
+            }
+            catch (Exception ex)
+            {
+                throw new InvalidOperationException(
+                    "OpenCV DNN CUDA runtime validation failed. Disable number AI GPU mode or use an OpenCV runtime built with CUDA DNN support.",
+                    ex);
+            }
+        }
+
         /// <summary>
         /// Detect text regions in the supplied image using the detection network.
         /// </summary>