[iOS/Android] MediaPicker: Fix image orientation when RotateImage=true

eng/pipelines/ci-device-tests.yml

@@ -5,6 +5,7 @@ trigger:
     - release/*
     - net*.0
     - inflight/*
+    - darc-*
   tags:
     include:
     - '*'

eng/pipelines/ci-uitests.yml

@@ -5,6 +5,7 @@ trigger:
     - release/*
     - net*.0
     - inflight/*
+    - darc-*
   tags:
     include:
     - '*'

src/Essentials/src/MediaPicker/ImageProcessor.android.cs

@@ -51,8 +51,8 @@ public static partial async Task<Stream> RotateImageAsync(Stream inputStream, st
 				return new MemoryStream(bytes);
 			}
 
-			// Apply EXIF orientation correction using SetRotate(0) to preserve original EXIF behavior
-			Bitmap? rotatedBitmap = ApplyExifOrientation(originalBitmap);
+			// Apply EXIF orientation correction with the actual orientation value
+			Bitmap? rotatedBitmap = ApplyExifOrientation(originalBitmap, orientation);
 			if (rotatedBitmap is null)
 			{
 				return new MemoryStream(bytes);
@@ -113,47 +113,92 @@ public static partial async Task<Stream> RotateImageAsync(Stream inputStream, st
 	/// </summary>
 	private static int GetExifOrientation(byte[] imageBytes)
 	{
+		var tempFileName = Path.Combine(Path.GetTempPath(), $"{Guid.NewGuid()}.jpg");
 		try
 		{
-			// Create a temporary file to read EXIF data
-			var tempFileName = Path.Combine(Path.GetTempPath(), $"{Guid.NewGuid()}.jpg");
 			using (var fileStream = File.Create(tempFileName))
 			{
 				fileStream.Write(imageBytes, 0, imageBytes.Length);
 			}
 
-			var exif = new ExifInterface(tempFileName);
-			int orientation = exif.GetAttributeInt(ExifInterface.TagOrientation, 1);
-
-			// Clean up temp file
-			try
-			{
-				File.Delete(tempFileName);
-			}
-			catch
-			{
-				// Ignore cleanup failures
-			}
-
-			return orientation;
+			using var exif = new ExifInterface(tempFileName);
+			return exif.GetAttributeInt(ExifInterface.TagOrientation, 1);
 		}
 		catch
 		{
 			return 1; // Default to normal orientation
 		}
+		finally
+		{
+			try { File.Delete(tempFileName); } catch { }
+		}
 	}
 
 	/// <summary>
-	/// Apply EXIF orientation correction by preserving original EXIF behavior
+	/// Apply EXIF orientation correction by rotating the bitmap according to EXIF orientation value
 	/// </summary>
-	private static Bitmap? ApplyExifOrientation(Bitmap bitmap)
+	private static Bitmap? ApplyExifOrientation(Bitmap bitmap, int orientation = 1)
 	{
 		try
 		{
-			// Use SetRotate(0) to preserve original EXIF orientation behavior
-			var matrix = new Matrix();
-			matrix.SetRotate(0);
-			return Bitmap.CreateBitmap(bitmap, 0, 0, bitmap.Width, bitmap.Height, matrix, true);
+			// Convert EXIF orientation to rotation angle and flip
+			// EXIF Orientation values:
+			// 1 = normal
+			// 2 = flip horizontal
+			// 3 = rotate 180°
+			// 4 = flip vertical
+			// 5 = rotate 90° CW + flip horizontal
+			// 6 = rotate 90° CW
+			// 7 = rotate 90° CCW + flip horizontal
+			// 8 = rotate 90° CCW
+
+			bool flipHorizontal = false;
+			bool flipVertical = false;
+			int rotationAngle = orientation switch
+			{
+				2 => 0,     // flip horizontal only
+				3 => 180,
+				4 => 0,     // flip vertical only
+				5 => 90,    // rotate 90° CW + flip horizontal
+				6 => 90,
+				7 => 270,   // rotate 270° CW + flip horizontal
+				8 => 270,
+				_ => 0      // 1 and other values mean no rotation needed
+			};
+
+			// Determine if we need to flip
+			flipHorizontal = orientation is 2 or 5 or 7;
+			flipVertical = orientation is 4;
+
+			// If no rotation and no flip needed, return original bitmap
+			if (rotationAngle == 0 && !flipHorizontal && !flipVertical)
+			{
+				return bitmap;
+			}
+
+			// Apply rotation and/or flip using a transformation matrix
+			using (var matrix = new Matrix())
+			{
+				float centerX = bitmap.Width / 2f;
+				float centerY = bitmap.Height / 2f;
+
+				// Apply rotation around center first, then flip.
+				// For orientations 5 & 7 the EXIF spec requires rotate-then-flip;
+				// reversing the order produces an incorrect result.
+				if (rotationAngle != 0)
+					matrix.PostRotate(rotationAngle, centerX, centerY);
+
+				if (flipHorizontal)
+					matrix.PostScale(-1, 1, centerX, centerY);
+
+				if (flipVertical)
+					matrix.PostScale(1, -1, centerX, centerY);
+
+				// Create transformed bitmap
+				var transformedBitmap = Bitmap.CreateBitmap(bitmap, 0, 0, bitmap.Width, bitmap.Height, matrix, true);
+
+				return transformedBitmap;
+			}
 		}
 		catch (Exception ex)
 		{
@@ -183,61 +228,58 @@ private static int GetExifOrientation(byte[] imageBytes)
 
 			// Create temporary file to extract EXIF data
 			var tempFileName = Path.Combine(Path.GetTempPath(), $"{Guid.NewGuid()}.jpg");
-			using (var fileStream = File.Create(tempFileName))
+			try
 			{
-				fileStream.Write(bytes, 0, bytes.Length);
-			}
-
-			// Extract all EXIF attributes
-			var exif = new ExifInterface(tempFileName);
-			var metadataList = new List<string>();
+				using (var fileStream = File.Create(tempFileName))
+				{
+					fileStream.Write(bytes, 0, bytes.Length);
+				}
 
-			// Extract common EXIF tags
-			var tags = new string[]
-			{
-				ExifInterface.TagArtist,
-				ExifInterface.TagCopyright,
-				ExifInterface.TagDatetime,
-				ExifInterface.TagImageDescription,
-				ExifInterface.TagMake,
-				ExifInterface.TagModel,
-				ExifInterface.TagOrientation,
-				ExifInterface.TagSoftware,
-				ExifInterface.TagGpsLatitude,
-				ExifInterface.TagGpsLongitude,
-				ExifInterface.TagGpsAltitude,
-				ExifInterface.TagExposureTime,
-				ExifInterface.TagFNumber,
-				ExifInterface.TagIso,
-				ExifInterface.TagWhiteBalance,
-				ExifInterface.TagFlash,
-				ExifInterface.TagFocalLength
-			};
+				// Extract all EXIF attributes
+				using var exif = new ExifInterface(tempFileName);
+				var metadataList = new List<string>();
 
-			foreach (var tag in tags)
-			{
-				var value = exif.GetAttribute(tag);
-				if (!string.IsNullOrEmpty(value))
+				// Extract common EXIF tags
+				var tags = new string[]
+				{
+					ExifInterface.TagArtist,
+					ExifInterface.TagCopyright,
+					ExifInterface.TagDatetime,
+					ExifInterface.TagImageDescription,
+					ExifInterface.TagMake,
+					ExifInterface.TagModel,
+					ExifInterface.TagOrientation,
+					ExifInterface.TagSoftware,
+					ExifInterface.TagGpsLatitude,
+					ExifInterface.TagGpsLongitude,
+					ExifInterface.TagGpsAltitude,
+					ExifInterface.TagExposureTime,
+					ExifInterface.TagFNumber,
+					ExifInterface.TagIso,
+					ExifInterface.TagWhiteBalance,
+					ExifInterface.TagFlash,
+					ExifInterface.TagFocalLength
+				};
+
+				foreach (var tag in tags)
 				{
-					metadataList.Add($"{tag}={value}");
+					var value = exif.GetAttribute(tag);
+					if (!string.IsNullOrEmpty(value))
+					{
+						metadataList.Add($"{tag}={value}");
+					}
 				}
-			}
 
-			// Serialize metadata to simple string format
-			var metadataString = string.Join("\n", metadataList);
-			var metadataBytes = System.Text.Encoding.UTF8.GetBytes(metadataString);
+				// Serialize metadata to simple string format
+				var metadataString = string.Join("\n", metadataList);
+				var metadataBytes = System.Text.Encoding.UTF8.GetBytes(metadataString);
 
-			// Clean up temp file
-			try
-			{
-				File.Delete(tempFileName);
+				return metadataBytes;
 			}
-			catch
+			finally
 			{
-				// Ignore cleanup failures
+				try { File.Delete(tempFileName); } catch { }
 			}
-
-			return metadataBytes;
 		}
 		catch
 		{
@@ -283,40 +325,36 @@ public static partial async Task<Stream> ApplyMetadataAsync(Stream processedStre
 
 			// Create temporary file to apply EXIF data
 			var tempFileName = Path.Combine(Path.GetTempPath(), $"{Guid.NewGuid()}.jpg");
-			using (var fileStream = File.Create(tempFileName))
-			{
-				fileStream.Write(bytes, 0, bytes.Length);
-			}
-
-			// Apply EXIF data
-			var exif = new ExifInterface(tempFileName);
-			foreach (var kvp in metadataDict)
+			try
 			{
-				try
+				using (var fileStream = File.Create(tempFileName))
 				{
-					exif.SetAttribute(kvp.Key, kvp.Value);
+					fileStream.Write(bytes, 0, bytes.Length);
 				}
-				catch
+
+				// Apply EXIF data
+				using var exif = new ExifInterface(tempFileName);
+				foreach (var kvp in metadataDict)
 				{
-					// Skip attributes that can't be set
+					try
+					{
+						exif.SetAttribute(kvp.Key, kvp.Value);
+					}
+					catch
+					{
+						// Skip attributes that can't be set
+					}
 				}
-			}
-			exif.SaveAttributes();
-
-			// Read back the file with applied metadata
-			var resultBytes = File.ReadAllBytes(tempFileName);
+				exif.SaveAttributes();
 
-			// Clean up temp file
-			try
-			{
-				File.Delete(tempFileName);
+				// Read back the file with applied metadata
+				var resultBytes = File.ReadAllBytes(tempFileName);
+				return new MemoryStream(resultBytes);
 			}
-			catch
+			finally
 			{
-				// Ignore cleanup failures
+				try { File.Delete(tempFileName); } catch { }
 			}
-
-			return new MemoryStream(resultBytes);
 		}
 		catch
 		{