Minor fixes.

src/ImageSharp/Formats/Bmp/BmpDecoder.cs

@@ -57,7 +57,7 @@ namespace SixLabors.ImageSharp.Formats.Bmp
         /// <inheritdoc />
         public async Task<Image> DecodeAsync(Configuration configuration, Stream stream, CancellationToken cancellationToken)
             => await this.DecodeAsync<Rgba32>(configuration, stream, cancellationToken)
-                .ConfigureAwait(false);
+            .ConfigureAwait(false);
 
         /// <inheritdoc/>
         public IImageInfo Identify(Configuration configuration, Stream stream)

src/ImageSharp/Formats/Gif/GifDecoder.cs

@@ -49,7 +49,7 @@ namespace SixLabors.ImageSharp.Formats.Gif
         /// <inheritdoc />
         public async Task<Image> DecodeAsync(Configuration configuration, Stream stream, CancellationToken cancellationToken)
             => await this.DecodeAsync<Rgba32>(configuration, stream, cancellationToken)
-                .ConfigureAwait(false);
+            .ConfigureAwait(false);
 
         /// <inheritdoc/>
         public IImageInfo Identify(Configuration configuration, Stream stream)

src/ImageSharp/Formats/ImageDecoderUtilities.cs

@@ -48,7 +48,7 @@ namespace SixLabors.ImageSharp.Formats
         {
             try
             {
-                using BufferedReadStream bufferedReadStream = new BufferedReadStream(configuration, stream);
+                using var bufferedReadStream = new BufferedReadStream(configuration, stream);
                 IImageInfo imageInfo = decoder.Identify(bufferedReadStream, cancellationToken);
                 return Task.FromResult(imageInfo);
             }
@@ -108,7 +108,7 @@ namespace SixLabors.ImageSharp.Formats
         {
             try
             {
-                using BufferedReadStream bufferedReadStream = new BufferedReadStream(configuration, stream);
+                using var bufferedReadStream = new BufferedReadStream(configuration, stream);
                 Image<TPixel> image = decoder.Decode<TPixel>(bufferedReadStream, cancellationToken);
                 return Task.FromResult(image);
             }
@@ -132,7 +132,7 @@ namespace SixLabors.ImageSharp.Formats
             Configuration configuration,
             Stream stream)
         {
-            using BufferedReadStream bufferedReadStream = new BufferedReadStream(configuration, stream);
+            using var bufferedReadStream = new BufferedReadStream(configuration, stream);
 
             try
             {
@@ -155,7 +155,7 @@ namespace SixLabors.ImageSharp.Formats
             Func<InvalidMemoryOperationException, Size, InvalidImageContentException> largeImageExceptionFactory)
             where TPixel : unmanaged, IPixel<TPixel>
         {
-            using BufferedReadStream bufferedReadStream = new BufferedReadStream(configuration, stream);
+            using var bufferedReadStream = new BufferedReadStream(configuration, stream);
 
             try
             {

src/ImageSharp/Formats/Jpeg/JpegDecoder.cs

@@ -44,7 +44,8 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
 
         /// <inheritdoc />
         public async Task<Image> DecodeAsync(Configuration configuration, Stream stream, CancellationToken cancellationToken)
-            => await this.DecodeAsync<Rgba32>(configuration, stream, cancellationToken).ConfigureAwait(false);
+            => await this.DecodeAsync<Rgba32>(configuration, stream, cancellationToken)
+            .ConfigureAwait(false);
 
         /// <inheritdoc/>
         public IImageInfo Identify(Configuration configuration, Stream stream)
@@ -56,12 +57,18 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
         }
 
         /// <inheritdoc/>
-        public Task<IImageInfo> IdentifyAsync(Configuration configuration, Stream stream, CancellationToken cancellationToken)
+        public async Task<IImageInfo> IdentifyAsync(Configuration configuration, Stream stream, CancellationToken cancellationToken)
         {
             Guard.NotNull(stream, nameof(stream));
 
-            using var decoder = new JpegDecoderCore(configuration, this);
+            // The introduction of a local variable that refers to an object the implements
-            return decoder.IdentifyAsync(configuration, stream, cancellationToken);
+            // IDisposable means you must use async/await, where the compiler generates the
+            // state machine and a continuation.
+            using (var decoder = new JpegDecoderCore(configuration, this))
+            {
+                return await decoder.IdentifyAsync(configuration, stream, cancellationToken)
+                    .ConfigureAwait(false);
+            }
         }
     }
 }

src/ImageSharp/Formats/Png/PngDecoder.cs

@@ -4,8 +4,6 @@
 using System.IO;
 using System.Threading;
 using System.Threading.Tasks;
-using SixLabors.ImageSharp.IO;
-using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.PixelFormats;
 
 namespace SixLabors.ImageSharp.Formats.Png
@@ -39,7 +37,8 @@ namespace SixLabors.ImageSharp.Formats.Png
 
         /// <inheritdoc />
         public async Task<Image> DecodeAsync(Configuration configuration, Stream stream, CancellationToken cancellationToken)
-            => await this.DecodeAsync<Rgba32>(configuration, stream, cancellationToken);
+            => await this.DecodeAsync<Rgba32>(configuration, stream, cancellationToken)
+            .ConfigureAwait(false);
 
         /// <inheritdoc/>
         public IImageInfo Identify(Configuration configuration, Stream stream)

src/ImageSharp/Formats/Png/PngEncoder.cs

@@ -77,6 +77,9 @@ namespace SixLabors.ImageSharp.Formats.Png
         public async Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream, CancellationToken cancellationToken)
             where TPixel : unmanaged, IPixel<TPixel>
         {
+            // The introduction of a local variable that refers to an object the implements
+            // IDisposable means you must use async/await, where the compiler generates the
+            // state machine and a continuation.
             using (var encoder = new PngEncoderCore(image.GetMemoryAllocator(), image.GetConfiguration(), new PngEncoderOptions(this)))
             {
                 await encoder.EncodeAsync(image, stream, cancellationToken).ConfigureAwait(false);

src/ImageSharp/Formats/Tga/TgaDecoder.cs

@@ -41,7 +41,8 @@ namespace SixLabors.ImageSharp.Formats.Tga
 
         /// <inheritdoc />
         public async Task<Image> DecodeAsync(Configuration configuration, Stream stream, CancellationToken cancellationToken)
-            => await this.DecodeAsync<Rgba32>(configuration, stream, cancellationToken);
+            => await this.DecodeAsync<Rgba32>(configuration, stream, cancellationToken)
+            .ConfigureAwait(false);
 
         /// <inheritdoc/>
         public IImageInfo Identify(Configuration configuration, Stream stream)