From 1f17a18600e4e69f8f2dc4707e0e50b45d2546ba Mon Sep 17 00:00:00 2001
From: Canming Huang <support@emgu.com>
Date: Fri, 5 Apr 2024 17:09:51 -0400
Subject: [PATCH] Minor optimization using Span.

---
 Emgu.CV.Models/Dnn/DetectedObject.cs               | 7 +++++++
 Emgu.CV.Models/Dnn/SceneTextDetector.cs            | 4 ++++
 Emgu.CV.OCR/Tesseract.cs                           | 4 ++++
 Emgu.CV.Platform/Emgu.CV.Bitmap/BitmapExtension.cs | 3 +--
 Emgu.CV/Imgproc/Subdiv2D.cs                        | 4 ++++
 Emgu.CV/Objdetect/HOGDescriptor.cs                 | 5 +++++
 6 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/Emgu.CV.Models/Dnn/DetectedObject.cs b/Emgu.CV.Models/Dnn/DetectedObject.cs
index e45ae7199..5389953da 100644
--- a/Emgu.CV.Models/Dnn/DetectedObject.cs
+++ b/Emgu.CV.Models/Dnn/DetectedObject.cs
@@ -123,9 +123,16 @@ namespace Emgu.CV.Models
                     regions,
                     confThreshold,
                     nmsThreshold);
+#if UNSAFE_ALLOWED
+                var classIdArr = classIds.GetSpan();
+                var confidentArr = confidents.GetSpan();
+                var regionArr = regions.GetSpan();
+#else
                 var classIdArr = classIds.ToArray();
                 var confidentArr = confidents.ToArray();
                 var regionArr = regions.ToArray();
+
+#endif
                 List<DetectedObject> results = new List<DetectedObject>();
                 for (int i = 0; i < classIdArr.Length; i++)
                 {
diff --git a/Emgu.CV.Models/Dnn/SceneTextDetector.cs b/Emgu.CV.Models/Dnn/SceneTextDetector.cs
index 978faf70c..0880b91ab 100644
--- a/Emgu.CV.Models/Dnn/SceneTextDetector.cs
+++ b/Emgu.CV.Models/Dnn/SceneTextDetector.cs
@@ -232,7 +232,11 @@ namespace Emgu.CV.Models
                 _textDetector.Detect(image, vvp, confidents);
 
                 Point[][] detectionResults = vvp.ToArrayOfArray();
+#if UNSAFE_ALLOWED
+                var confidentResult = confidents.GetSpan();
+#else
                 float[] confidentResult = confidents.ToArray();
+#endif
                 List<DetectedObject> results = new List<DetectedObject>();
                 for (int i = 0; i < detectionResults.Length; i++)
                 {
diff --git a/Emgu.CV.OCR/Tesseract.cs b/Emgu.CV.OCR/Tesseract.cs
index 75918458c..73dada65c 100644
--- a/Emgu.CV.OCR/Tesseract.cs
+++ b/Emgu.CV.OCR/Tesseract.cs
@@ -503,7 +503,11 @@ namespace Emgu.CV.OCR
                 OcrInvoke.cveTessBaseAPIExtractResult(_ptr, textSeq, results);
 
                 byte[] bytes = textSeq.ToArray();
+#if UNSAFE_ALLOWED
+                var trs = results.GetSpan();
+#else
                 TesseractResult[] trs = results.ToArray();
+#endif
 
                 Word[] res = new Word[trs.Length];
                 int idx = 0;
diff --git a/Emgu.CV.Platform/Emgu.CV.Bitmap/BitmapExtension.cs b/Emgu.CV.Platform/Emgu.CV.Bitmap/BitmapExtension.cs
index cea09b759..ea411b091 100644
--- a/Emgu.CV.Platform/Emgu.CV.Bitmap/BitmapExtension.cs
+++ b/Emgu.CV.Platform/Emgu.CV.Bitmap/BitmapExtension.cs
@@ -813,8 +813,7 @@ namespace Emgu.CV
                 Bitmap result = new Bitmap(s.Width, s.Height, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
                 System.Drawing.Imaging.BitmapData data = result.LockBits(new Rectangle(Point.Empty, result.Size),
                     System.Drawing.Imaging.ImageLockMode.WriteOnly, result.PixelFormat);
-                using (Image<TColor, TDepth> tmp = new Image<TColor, TDepth>(s.Width, s.Height, data.Stride, data.Scan0)
-                )
+                using (Image<TColor, TDepth> tmp = new Image<TColor, TDepth>(s.Width, s.Height, data.Stride, data.Scan0))
                 {
                     cudaImage.Download(tmp);
                 }
diff --git a/Emgu.CV/Imgproc/Subdiv2D.cs b/Emgu.CV/Imgproc/Subdiv2D.cs
index 77af511ad..03f165f7e 100644
--- a/Emgu.CV/Imgproc/Subdiv2D.cs
+++ b/Emgu.CV/Imgproc/Subdiv2D.cs
@@ -124,7 +124,11 @@ namespace Emgu.CV
 
                 CvInvoke.cveSubdiv2DGetVoronoiFacetList(_ptr, vi, facetVec, centerVec);
                 PointF[][] vertices = facetVec.ToArrayOfArray();
+#if UNSAFE_ALLOWED
+                var centers = centerVec.GetSpan();
+#else
                 PointF[] centers = centerVec.ToArray();
+#endif
 
                 VoronoiFacet[] facets = new VoronoiFacet[centers.Length];
                 for (int i = 0; i < facets.Length; i++)
diff --git a/Emgu.CV/Objdetect/HOGDescriptor.cs b/Emgu.CV/Objdetect/HOGDescriptor.cs
index a4fcf48e9..28bf007cd 100644
--- a/Emgu.CV/Objdetect/HOGDescriptor.cs
+++ b/Emgu.CV/Objdetect/HOGDescriptor.cs
@@ -114,8 +114,13 @@ namespace Emgu.CV
             {
                 ObjdetectInvoke.cveHOGDescriptorDetectMultiScale(_ptr, iaImage, vr, vd, hitThreshold, ref winStride, ref padding, scale,
                    finalThreshold, useMeanshiftGrouping);
+#if UNSAFE_ALLOWED
+                var location = vr.GetSpan();
+                var weight = vd.GetSpan();
+#else
                 Rectangle[] location = vr.ToArray();
                 double[] weight = vd.ToArray();
+#endif
                 MCvObjectDetection[] result = new MCvObjectDetection[location.Length];
                 for (int i = 0; i < result.Length; i++)
                 {