Android EXIF orientation calculates proper size before downsampling #130

luberda-molinet · Jan 26, 2016 · 7114cbc · 7114cbc · molinch · Jan 27, 2016
1 parent 1279712
commit 7114cbc
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Showing 2 changed files with 65 additions and 49 deletions.
diff --git a/source/FFImageLoading.Droid/Extensions/ExifExtensions.cs b/source/FFImageLoading.Droid/Extensions/ExifExtensions.cs
@@ -1,69 +1,70 @@
 using System;
 using Android.Graphics;
-using FFImageLoading.Work;
 using Android.Media;
 
 namespace FFImageLoading.Extensions
 {
 	public static class ExifExtensions
 	{
-		public static Bitmap ToExifRotatedBitmap(this Bitmap sourceBitmap, ImageSource source, string identifier)
+		public static int GetExifRotationDegrees(this string filePath)
 		{
-			if (source == ImageSource.Filepath)
-			{
-				int rotation = 0;
-				var exifInt = new ExifInterface(identifier);
-				int exifRotation = exifInt.GetAttributeInt(ExifInterface.TagOrientation, (int)Orientation.Normal);
+			int rotation = 0;
+			var exifInt = new ExifInterface(filePath);
+			int exifRotation = exifInt.GetAttributeInt(ExifInterface.TagOrientation, (int)Orientation.Normal);
 
-				switch (exifRotation)
-				{
-					case (int) Orientation.Rotate270:
-						rotation = 270;
-						break;
-					case (int) Orientation.Rotate180:
-						rotation = 180;
-						break;
-					case (int) Orientation.Rotate90:
-						rotation = 90;
-						break;
-				}
+			switch (exifRotation)
+			{
+				case (int) Orientation.Rotate270:
+					rotation = 270;
+					break;
+				case (int) Orientation.Rotate180:
+					rotation = 180;
+					break;
+				case (int) Orientation.Rotate90:
+					rotation = 90;
+					break;
+				default:
+					return 0;
+			}
 
-				if (rotation == 0)
-					return sourceBitmap;
+			return rotation;
+		}
 
-				int width = sourceBitmap.Width;
-				int height = sourceBitmap.Height;
+		public static Bitmap ToRotatedBitmap(this Bitmap sourceBitmap, int rotationDegrees)
+		{
+			if (rotationDegrees == 0)
+				return sourceBitmap;
 
-				if (rotation == 90 || rotation == 270) 
-				{
-					width = sourceBitmap.Height;
-					height = sourceBitmap.Width;
-				}
+			int width = sourceBitmap.Width;
+			int height = sourceBitmap.Height;
 
-				Bitmap bitmap = Bitmap.CreateBitmap(width, height, sourceBitmap.GetConfig());
-				using (Canvas canvas = new Canvas(bitmap))
-				using (Paint paint = new Paint())
-				using (BitmapShader shader = new BitmapShader(sourceBitmap, Shader.TileMode.Clamp, Shader.TileMode.Clamp))
-				using (Matrix matrix = new Matrix())
-				{
-					// paint.AntiAlias = true;
-					// paint.Dither = true;
-					// paint.FilterBitmap = true;
+			if (rotationDegrees == 90 || rotationDegrees == 270) 
+			{
+				width = sourceBitmap.Height;
+				height = sourceBitmap.Width;
+			}
 
-					matrix.PostRotate(rotation);
-					canvas.DrawBitmap(sourceBitmap, matrix, paint);
-				}
+			Bitmap bitmap = Bitmap.CreateBitmap(width, height, sourceBitmap.GetConfig());
+			using (Canvas canvas = new Canvas(bitmap))
+			using (Paint paint = new Paint())
+			using (BitmapShader shader = new BitmapShader(sourceBitmap, Shader.TileMode.Clamp, Shader.TileMode.Clamp))
+			using (Matrix matrix = new Matrix())
+			{
+				// paint.AntiAlias = true;
+				// paint.Dither = true;
+				// paint.FilterBitmap = true;
 
-				if (sourceBitmap != null && sourceBitmap.Handle != IntPtr.Zero && !sourceBitmap.IsRecycled)
-				{
-					sourceBitmap.Recycle();
-					sourceBitmap.Dispose();	
-				}
+				matrix.PostRotate(rotationDegrees);
+				canvas.DrawBitmap(sourceBitmap, matrix, paint);
+			}
 
-				return bitmap;
+			if (sourceBitmap != null && sourceBitmap.Handle != IntPtr.Zero && !sourceBitmap.IsRecycled)
+			{
+				sourceBitmap.Recycle();
+				sourceBitmap.Dispose();	
 			}
-			
-			return sourceBitmap;
+
+			return bitmap;
 		}
 	}
 }

diff --git a/source/FFImageLoading.Droid/Work/ImageLoaderTask.cs b/source/FFImageLoading.Droid/Work/ImageLoaderTask.cs
@@ -375,6 +375,13 @@ protected virtual async Task<WithLoadingResult<SelfDisposingBitmapDrawable>> Get
 							options.InPreferredConfig = Bitmap.Config.Rgb565;
 						}
 
+						// CHECK IF BITMAP IS EXIF ROTATED
+						int exifRotation = 0;
+						if (source == ImageSource.Filepath)
+						{
+							exifRotation = path.GetExifRotationDegrees();
+						}
+
 						try
 						{
 							if (Parameters.DownSampleSize != null && (Parameters.DownSampleSize.Item1 > 0 || Parameters.DownSampleSize.Item2 > 0))
@@ -384,6 +391,13 @@ protected virtual async Task<WithLoadingResult<SelfDisposingBitmapDrawable>> Get
 								int downsampleWidth = Parameters.DownSampleSize.Item1;
 								int downsampleHeight = Parameters.DownSampleSize.Item2;
 
+								// if image is rotated, swap width/height
+								if (exifRotation == 90 || exifRotation == 270) 
+								{
+									downsampleWidth = Parameters.DownSampleSize.Item2;
+									downsampleHeight = Parameters.DownSampleSize.Item1;
+								}
+
 								if (Parameters.DownSampleUseDipUnits)
 								{
 									downsampleWidth = downsampleWidth.DpToPixels();
@@ -440,7 +454,8 @@ protected virtual async Task<WithLoadingResult<SelfDisposingBitmapDrawable>> Get
 							return null;
 
 						// APPLY EXIF ORIENTATION IF NEEDED
-						bitmap = bitmap.ToExifRotatedBitmap(source, path);
+						if (exifRotation != 0)
+							bitmap = bitmap.ToRotatedBitmap(exifRotation);
 
 						bool transformPlaceholdersEnabled = Parameters.TransformPlaceholdersEnabled.HasValue ? 
 							Parameters.TransformPlaceholdersEnabled.Value : ImageService.Config.TransformPlaceholders;