[develop] Prepare for August 2026 Release

IronSoftware.Drawing/IronSoftware.Drawing.Common.Tests/UnitTests/AnyBitmapFunctionality.cs

@@ -650,6 +650,21 @@ public void FromTiffFile_MissingFile_ThrowsFileNotFound()
             act.Should().Throw<FileNotFoundException>();
         }
 
+        [TheoryWithAutomaticDisplayName]
+        [InlineData("example.tif")]                 // 24 bpp
+        [InlineData("test_dw_10.tif")]              // 1 bpp, multi-page
+        [InlineData("multiframe.tiff")]            // 16 bpp
+        public void FromTiffFile_BitsPerPixel_MatchesFromFile(string fileName)
+        {
+            string tiffPath = GetRelativeFilePath(fileName);
+
+            int expected = AnyBitmap.FromFile(tiffPath).BitsPerPixel;
+            int streamed = AnyBitmap.FromTiffFile(tiffPath).BitsPerPixel;
+
+            streamed.Should().Be(expected,
+                $"FromTiffFile should report the source color depth for '{fileName}', matching FromFile");
+        }
+
         [FactWithAutomaticDisplayName]
         public void Create_Multi_page_Tiff()
         {

IronSoftware.Drawing/IronSoftware.Drawing.Common/AnyBitmap.cs

@@ -963,7 +963,8 @@ public static AnyBitmap FromTiffFile(string file)
             }
 
             AnyBitmap bitmap = new();
-            bitmap.LoadLargeTiffFromFile(file);
+            // Preserve the source color depth so BitsPerPixel reports it, matching FromFile.
+            bitmap.LoadLargeTiffFromFile(file, preserveOriginalFormat: true);
             return bitmap;
         }
 
@@ -3270,7 +3271,7 @@ private void LoadImageFromFile(string file, bool preserveOriginalFormat)
                 if (IsTiffFile(file))
                 {
                     // Stream the TIFF page-by-page; never materialise the whole file.
-                    LoadLargeTiffFromFile(file);
+                    LoadLargeTiffFromFile(file, preserveOriginalFormat);
                     return;
                 }
 
@@ -3315,7 +3316,12 @@ private static bool IsTiffFile(string file)
         /// time through the underlying <see cref="FileStream"/>, so the entire file
         /// is never allocated as one array, enabling TIFF files larger than 2 GB.
         /// </summary>
-        private void LoadLargeTiffFromFile(string file)
+        /// <param name="file">A fully qualified path to a TIFF file.</param>
+        /// <param name="preserveOriginalFormat">When <c>true</c>, report the source
+        /// color depth from <see cref="BitsPerPixel"/> (as <see cref="FromFile(string)"/>
+        /// does) instead of the decoded 32bpp value. The pixels are always decoded to
+        /// Rgba32 on this path regardless of the flag.</param>
+        private void LoadLargeTiffFromFile(string file, bool preserveOriginalFormat)
         {
             Tiff.SetErrorHandler(new DisableErrorHandler());
 
@@ -3331,6 +3337,7 @@ private void LoadLargeTiffFromFile(string file)
 
                 try
                 {
+                    // ReadTiffFrames also populates _framesOriginalBitsPerPixel (per-frame source depth).
                     frames = ReadTiffFrames(tiff);
                 }
                 catch (DllNotFoundException e)
@@ -3345,6 +3352,13 @@ private void LoadLargeTiffFromFile(string file)
                     $"The TIFF file '{file}' was opened but contained no decodable image pages.");
             }
 
+            if (preserveOriginalFormat)
+            {
+                _originalBitsPerPixel = _framesOriginalBitsPerPixel != null && _framesOriginalBitsPerPixel.Count > 0
+                    ? _framesOriginalBitsPerPixel[0]
+                    : null;
+            }
+
             // Hold the decoded pages directly. Binary is deliberately NOT set: the
             // source file may be larger than a single byte[] can hold. The
             // _streamedFromTiff flag tells the Binary getter to re-encode the pages as

NuGet/IronSoftware.Drawing.nuspec

@@ -42,12 +42,11 @@ For general support and technical inquiries, please email us at: support@ironsof
 		<summary>IronSoftware.System.Drawing is an open-source solution for .NET developers to replace System.Drawing.Common with a universal and flexible library.</summary>
 		<releaseNotes>
 Features
-- Added support for creating multi-page TIFFs while preserving per-page dimensions, orientation, and resolution
+- Added support for loading TIFF and BigTIFF files larger than 2 GB using a streaming loader, enabling page-by-page decoding without loading the entire file into memory
 Enhancements
-- Added support for converting AnyBitmap images to 8, 24, or 32 bits per pixel
+- AnyBitmap now preserves the original source color depth (BitsPerPixel) across derived operations, including frame extraction, cloning, rotation, redaction, and resizing
 Bug Fixes
-- Fixed an issue where AnyBitmap.BitsPerPixel reported incorrect color depths for TIFF images
-- Fixed issues affecting multi-page TIFF generation, including incorrect resolution metadata and corrupted output for certain RGB image formats
+- Fixed an issue where derived AnyBitmap operations incorrectly reported a decoded 32bpp color depth instead of the original source pixel depth
 		</releaseNotes>
 		<copyright>Copyright © Iron Software 2022-2026</copyright>
 		<tags>Images, Bitmap, SkiaSharp, SixLabors, BitMiracle, Maui, SVG, TIFF, TIF, GIF, JPEG, PNG, Color, Rectangle, Drawing, C#, VB.NET, ASPX, create, render, generate, standard, netstandard2.0, core, netcore</tags>