Few improvements to Tesseract API.

GeReV · Dec 10, 2024 · 3d32a1c · 3d32a1c
1 parent 3e72291
commit 3d32a1c
Showing 3 changed files with 55 additions and 40 deletions.
diff --git a/HocrEditor.Tesseract/TesseractApi.cs b/HocrEditor.Tesseract/TesseractApi.cs
@@ -136,8 +136,8 @@ public bool GetDoubleVariable(string name, out double value)
     public void SetInputName(string name) =>
         tesseractDllHandle.TessBaseAPISetInputName(apiHandle.DangerousGetHandle(), name);
 
-    public void SetImage(byte[] data, int width, int height, int bytesPerPixel, int bytesPerLine) =>
-        tesseractDllHandle.TessBaseAPISetImage(apiHandle.DangerousGetHandle(), data, width, height, bytesPerPixel, bytesPerLine);
+    public void SetImage(ReadOnlySpan<byte> data, int width, int height, int bytesPerPixel, int bytesPerLine) =>
+        tesseractDllHandle.TessBaseAPISetImage(apiHandle.DangerousGetHandle(), MemoryMarshal.GetReference(data), width, height, bytesPerPixel, bytesPerLine);
 
     public void SetSourceResolution(int ppi) =>
         tesseractDllHandle.TessBaseAPISetSourceResolution(apiHandle.DangerousGetHandle(), ppi);

diff --git a/HocrEditor.Tesseract/TesseractDllHandle.cs b/HocrEditor.Tesseract/TesseractDllHandle.cs
@@ -126,7 +126,7 @@ int configSize
 
         internal delegate void TessBaseAPISetImage(
             IntPtr handle,
-            byte[] data,
+            in byte data,
             int width,
             int height,
             int bytesPerPixel,

diff --git a/HocrEditor.Tesseract/TesseractService.cs b/HocrEditor.Tesseract/TesseractService.cs
@@ -1,15 +1,41 @@
-using System.Diagnostics;
-using System.Drawing;
+using System.Drawing;
+using System.Security;
+using Microsoft.Win32;
+using Optional;
 using SkiaSharp;
 
 namespace HocrEditor.Tesseract;
 
 public sealed class TesseractService : IDisposable
 {
     private bool isDisposed;
-    private readonly object lck = new();
+    private readonly Lock lck = new();
     private readonly TesseractApi tesseractApi;
 
+    public static Option<string> DefaultPath
+    {
+        get
+        {
+            const string tesseractKey = "SOFTWARE\\Tesseract-OCR";
+
+            try
+            {
+                using var tesseractRegistryKey = Registry.CurrentUser.OpenSubKey(tesseractKey) ??
+                                                 Registry.LocalMachine.OpenSubKey(tesseractKey);
+
+                if (tesseractRegistryKey?.GetValue("Path") is string path)
+                {
+                    return Option.Some(path);
+                }
+            }
+            catch (SecurityException)
+            {
+            }
+
+            return Option.None<string>();
+        }
+    }
+
     public TesseractService(string tesseractPath, IEnumerable<string> languages)
     {
         tesseractApi = TesseractFactory.CreateApi(tesseractPath);
@@ -46,58 +72,50 @@ public string[] GetLanguages()
 
     public SKBitmap GetThresholdedImage(SKBitmap image, Rectangle region = new())
     {
-        if (isDisposed)
-        {
-            throw new ObjectDisposedException(nameof(tesseractApi));
-        }
+        ObjectDisposedException.ThrowIf(isDisposed, this);
 
         lock (lck)
         {
-            var bytes = GetBitmapBytes(image);
-
-            tesseractApi.SetImage(bytes, image.Width, image.Height, image.BytesPerPixel, image.RowBytes);
+            tesseractApi.SetImage(image.GetPixelSpan(), image.Width, image.Height, image.BytesPerPixel, image.RowBytes);
 
             return tesseractApi.GetThresholdedImage();
         }
     }
 
     public async Task<string> Recognize(SKBitmap image, string imageFilename, Rectangle region = new())
     {
-        if (isDisposed)
-        {
-            throw new ObjectDisposedException(nameof(tesseractApi));
-        }
+        ObjectDisposedException.ThrowIf(isDisposed, this);
 
         return await Task.Run(
-            () =>
-            {
-                lock (lck)
+                () =>
                 {
-                    if (isDisposed)
+                    lock (lck)
                     {
-                        throw new ObjectDisposedException(nameof(tesseractApi));
-                    }
+                        ObjectDisposedException.ThrowIf(isDisposed, this);
 
-                    var bytes = GetBitmapBytes(image);
+                        tesseractApi.SetInputName(imageFilename);
+                        tesseractApi.SetImage(
+                            image.GetPixelSpan(),
+                            image.Width,
+                            image.Height,
+                            image.BytesPerPixel,
+                            image.RowBytes
+                        );
 
-                    tesseractApi.SetInputName(imageFilename);
-                    tesseractApi.SetImage(bytes, image.Width, image.Height, image.BytesPerPixel, image.RowBytes);
+                        // tesseractApi.SetSourceResolution(300);
 
-                    // tesseractApi.SetSourceResolution(300);
+                        if (!region.IsEmpty)
+                        {
+                            tesseractApi.SetRectangle(region.X, region.Y, region.Width, region.Height);
+                        }
 
-                    if (!region.IsEmpty)
-                    {
-                        tesseractApi.SetRectangle(region.X, region.Y, region.Width, region.Height);
+                        return tesseractApi.GetHocrText();
                     }
-
-                    return tesseractApi.GetHocrText();
                 }
-            }
-        ).ConfigureAwait(false);
+            )
+            .ConfigureAwait(false);
     }
 
-    private static byte[] GetBitmapBytes(SKBitmap image) => image.GetPixelSpan().ToArray();
-
     public void Dispose()
     {
         if (isDisposed)
@@ -107,10 +125,7 @@ public void Dispose()
 
         lock (lck)
         {
-            if (isDisposed)
-            {
-                throw new ObjectDisposedException(nameof(tesseractApi));
-            }
+            ObjectDisposedException.ThrowIf(isDisposed, this);
 
             tesseractApi.Clear();
             tesseractApi.Dispose();