Remove some nullable disable comments

src/ImageSharp/Advanced/AdvancedImageExtensions.cs

@@ -27,8 +27,7 @@ public static IImageEncoder DetectEncoder(this Image source, string filePath)
         Guard.NotNull(filePath, nameof(filePath));
 
         string ext = Path.GetExtension(filePath);
-        IImageFormat format = source.GetConfiguration().ImageFormatsManager.FindFormatByFileExtension(ext);
-        if (format is null)
+        if (!source.GetConfiguration().ImageFormatsManager.TryFindFormatByFileExtension(ext, out IImageFormat? format))
         {
             StringBuilder sb = new();
             sb.AppendLine(CultureInfo.InvariantCulture, $"No encoder was found for extension '{ext}'. Registered encoders include:");
@@ -40,7 +39,7 @@ public static IImageEncoder DetectEncoder(this Image source, string filePath)
             throw new NotSupportedException(sb.ToString());
         }
 
-        IImageEncoder encoder = source.GetConfiguration().ImageFormatsManager.FindEncoder(format);
+        IImageEncoder? encoder = source.GetConfiguration().ImageFormatsManager.FindEncoder(format);
 
         if (encoder is null)
         {

src/ImageSharp/Formats/Bmp/BmpImageFormatDetector.cs

@@ -1,8 +1,8 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Buffers.Binary;
+using System.Diagnostics.CodeAnalysis;
 
 namespace SixLabors.ImageSharp.Formats.Bmp;
 
@@ -15,17 +15,20 @@ public sealed class BmpImageFormatDetector : IImageFormatDetector
     public int HeaderSize => 2;
 
     /// <inheritdoc/>
-    public IImageFormat DetectFormat(ReadOnlySpan<byte> header)
+    public bool TryDetectFormat(ReadOnlySpan<byte> header, [NotNullWhen(true)] out IImageFormat? format)
     {
-        return this.IsSupportedFileFormat(header) ? BmpFormat.Instance : null;
+        format = this.IsSupportedFileFormat(header) ? BmpFormat.Instance : null;
+
+        return format != null;
     }
 
     private bool IsSupportedFileFormat(ReadOnlySpan<byte> header)
     {
         if (header.Length >= this.HeaderSize)
         {
             short fileTypeMarker = BinaryPrimitives.ReadInt16LittleEndian(header);
-            return fileTypeMarker == BmpConstants.TypeMarkers.Bitmap || fileTypeMarker == BmpConstants.TypeMarkers.BitmapArray;
+            return fileTypeMarker == BmpConstants.TypeMarkers.Bitmap ||
+                   fileTypeMarker == BmpConstants.TypeMarkers.BitmapArray;
         }
 
         return false;

src/ImageSharp/Formats/Gif/GifImageFormatDetector.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
+
+using System.Diagnostics.CodeAnalysis;
 
 namespace SixLabors.ImageSharp.Formats.Gif;
 
@@ -13,9 +14,10 @@ public sealed class GifImageFormatDetector : IImageFormatDetector
     public int HeaderSize => 6;
 
     /// <inheritdoc/>
-    public IImageFormat DetectFormat(ReadOnlySpan<byte> header)
+    public bool TryDetectFormat(ReadOnlySpan<byte> header, [NotNullWhen(true)] out IImageFormat? format)
     {
-        return this.IsSupportedFileFormat(header) ? GifFormat.Instance : null;
+        format = this.IsSupportedFileFormat(header) ? GifFormat.Instance : null;
+        return format != null;
     }
 
     private bool IsSupportedFileFormat(ReadOnlySpan<byte> header)

src/ImageSharp/Formats/IImageFormatDetector.cs

@@ -1,6 +1,8 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+using System.Diagnostics.CodeAnalysis;
+
 namespace SixLabors.ImageSharp.Formats;
 
 /// <summary>
@@ -18,6 +20,7 @@ public interface IImageFormatDetector
     /// Detect mimetype
     /// </summary>
     /// <param name="header">The <see cref="T:byte[]"/> containing the file header.</param>
-    /// <returns>returns the mime type of detected otherwise returns null</returns>
-    IImageFormat DetectFormat(ReadOnlySpan<byte> header);
+    /// <param name="format">The mime type of detected otherwise returns null</param>
+    /// <returns>returns true when format was detected otherwise false.</returns>
+    bool TryDetectFormat(ReadOnlySpan<byte> header, [NotNullWhen(true)] out IImageFormat? format);
 }

src/ImageSharp/Formats/ImageDecoderUtilities.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using SixLabors.ImageSharp.IO;
 using SixLabors.ImageSharp.Memory;

src/ImageSharp/Formats/ImageFormatManager.cs

@@ -1,8 +1,8 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Collections.Concurrent;
+using System.Diagnostics.CodeAnalysis;
 
 namespace SixLabors.ImageSharp.Formats;
 
@@ -92,8 +92,9 @@ public void AddImageFormat(IImageFormat format)
     /// For the specified file extensions type find the e <see cref="IImageFormat"/>.
     /// </summary>
     /// <param name="extension">The extension to discover</param>
-    /// <returns>The <see cref="IImageFormat"/> if found otherwise null</returns>
-    public IImageFormat FindFormatByFileExtension(string extension)
+    /// <param name="format">The <see cref="IImageFormat"/> if found otherwise null</param>
+    /// <returns>False if no format was found</returns>
+    public bool TryFindFormatByFileExtension(string extension, [NotNullWhen(true)] out IImageFormat? format)
     {
         Guard.NotNullOrWhiteSpace(extension, nameof(extension));
 
@@ -102,15 +103,18 @@ public IImageFormat FindFormatByFileExtension(string extension)
             extension = extension[1..];
         }
 
-        return this.imageFormats.FirstOrDefault(x => x.FileExtensions.Contains(extension, StringComparer.OrdinalIgnoreCase));
+        format = this.imageFormats.FirstOrDefault(x =>
+            x.FileExtensions.Contains(extension, StringComparer.OrdinalIgnoreCase));
+
+        return format != null;
     }
 
     /// <summary>
     /// For the specified mime type find the <see cref="IImageFormat"/>.
     /// </summary>
     /// <param name="mimeType">The mime-type to discover</param>
     /// <returns>The <see cref="IImageFormat"/> if found; otherwise null</returns>
-    public IImageFormat FindFormatByMimeType(string mimeType)
+    public IImageFormat? FindFormatByMimeType(string mimeType)
         => this.imageFormats.FirstOrDefault(x => x.MimeTypes.Contains(mimeType, StringComparer.OrdinalIgnoreCase));
 
     /// <summary>
@@ -160,11 +164,11 @@ public void AddImageFormatDetector(IImageFormatDetector detector)
     /// </summary>
     /// <param name="format">The format to discover</param>
     /// <returns>The <see cref="IImageDecoder"/> if found otherwise null</returns>
-    public IImageDecoder FindDecoder(IImageFormat format)
+    public IImageDecoder? FindDecoder(IImageFormat format)
     {
         Guard.NotNull(format, nameof(format));
 
-        return this.mimeTypeDecoders.TryGetValue(format, out IImageDecoder decoder)
+        return this.mimeTypeDecoders.TryGetValue(format, out IImageDecoder? decoder)
             ? decoder
             : null;
     }
@@ -174,11 +178,11 @@ public IImageDecoder FindDecoder(IImageFormat format)
     /// </summary>
     /// <param name="format">The format to discover</param>
     /// <returns>The <see cref="IImageEncoder"/> if found otherwise null</returns>
-    public IImageEncoder FindEncoder(IImageFormat format)
+    public IImageEncoder? FindEncoder(IImageFormat format)
     {
         Guard.NotNull(format, nameof(format));
 
-        return this.mimeTypeEncoders.TryGetValue(format, out IImageEncoder encoder)
+        return this.mimeTypeEncoders.TryGetValue(format, out IImageEncoder? encoder)
             ? encoder
             : null;
     }

src/ImageSharp/Formats/Jpeg/JpegImageFormatDetector.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
+
+using System.Diagnostics.CodeAnalysis;
 
 namespace SixLabors.ImageSharp.Formats.Jpeg;
 
@@ -13,8 +14,11 @@ public sealed class JpegImageFormatDetector : IImageFormatDetector
     public int HeaderSize => 11;
 
     /// <inheritdoc/>
-    public IImageFormat DetectFormat(ReadOnlySpan<byte> header)
-        => this.IsSupportedFileFormat(header) ? JpegFormat.Instance : null;
+    public bool TryDetectFormat(ReadOnlySpan<byte> header, [NotNullWhen(true)] out IImageFormat? format)
+    {
+        format = this.IsSupportedFileFormat(header) ? JpegFormat.Instance : null;
+        return format != null;
+    }
 
     private bool IsSupportedFileFormat(ReadOnlySpan<byte> header)
         => header.Length >= this.HeaderSize

src/ImageSharp/Formats/Pbm/PbmImageFormatDetector.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
+
+using System.Diagnostics.CodeAnalysis;
 
 namespace SixLabors.ImageSharp.Formats.Pbm;
 
@@ -17,7 +18,11 @@ public sealed class PbmImageFormatDetector : IImageFormatDetector
     public int HeaderSize => 2;
 
     /// <inheritdoc/>
-    public IImageFormat DetectFormat(ReadOnlySpan<byte> header) => IsSupportedFileFormat(header) ? PbmFormat.Instance : null;
+    public bool TryDetectFormat(ReadOnlySpan<byte> header, [NotNullWhen(true)] out IImageFormat? format)
+    {
+        format = IsSupportedFileFormat(header) ? PbmFormat.Instance : null;
+        return format != null;
+    }
 
     private static bool IsSupportedFileFormat(ReadOnlySpan<byte> header)
     {

src/ImageSharp/Formats/Png/PngImageFormatDetector.cs

@@ -1,8 +1,8 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Buffers.Binary;
+using System.Diagnostics.CodeAnalysis;
 
 namespace SixLabors.ImageSharp.Formats.Png;
 
@@ -15,9 +15,10 @@ public sealed class PngImageFormatDetector : IImageFormatDetector
     public int HeaderSize => 8;
 
     /// <inheritdoc/>
-    public IImageFormat DetectFormat(ReadOnlySpan<byte> header)
+    public bool TryDetectFormat(ReadOnlySpan<byte> header, [NotNullWhen(true)] out IImageFormat? format)
     {
-        return this.IsSupportedFileFormat(header) ? PngFormat.Instance : null;
+        format = this.IsSupportedFileFormat(header) ? PngFormat.Instance : null;
+        return format != null;
     }
 
     private bool IsSupportedFileFormat(ReadOnlySpan<byte> header)

src/ImageSharp/Formats/Tga/TgaImageFormatDetector.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
+
+using System.Diagnostics.CodeAnalysis;
 
 namespace SixLabors.ImageSharp.Formats.Tga;
 
@@ -13,9 +14,10 @@ public sealed class TgaImageFormatDetector : IImageFormatDetector
     public int HeaderSize => 16;
 
     /// <inheritdoc/>
-    public IImageFormat DetectFormat(ReadOnlySpan<byte> header)
+    public bool TryDetectFormat(ReadOnlySpan<byte> header, [NotNullWhen(true)] out IImageFormat? format)
     {
-        return this.IsSupportedFileFormat(header) ? TgaFormat.Instance : null;
+        format = this.IsSupportedFileFormat(header) ? TgaFormat.Instance : null;
+        return format != null;
     }
 
     private bool IsSupportedFileFormat(ReadOnlySpan<byte> header)

src/ImageSharp/Formats/Tiff/TiffImageFormatDetector.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
+
+using System.Diagnostics.CodeAnalysis;
 
 namespace SixLabors.ImageSharp.Formats.Tiff;
 
@@ -13,14 +14,10 @@ public sealed class TiffImageFormatDetector : IImageFormatDetector
     public int HeaderSize => 8;
 
     /// <inheritdoc/>
-    public IImageFormat DetectFormat(ReadOnlySpan<byte> header)
+    public bool TryDetectFormat(ReadOnlySpan<byte> header, [NotNullWhen(true)] out IImageFormat? format)
     {
-        if (this.IsSupportedFileFormat(header))
-        {
-            return TiffFormat.Instance;
-        }
-
-        return null;
+        format = this.IsSupportedFileFormat(header) ? TiffFormat.Instance : null;
+        return format != null;
     }
 
     private bool IsSupportedFileFormat(ReadOnlySpan<byte> header)

src/ImageSharp/Formats/Webp/WebpImageFormatDetector.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
+
+using System.Diagnostics.CodeAnalysis;
 
 namespace SixLabors.ImageSharp.Formats.Webp;
 
@@ -13,8 +14,11 @@ public sealed class WebpImageFormatDetector : IImageFormatDetector
     public int HeaderSize => 12;
 
     /// <inheritdoc />
-    public IImageFormat DetectFormat(ReadOnlySpan<byte> header)
-        => this.IsSupportedFileFormat(header) ? WebpFormat.Instance : null;
+    public bool TryDetectFormat(ReadOnlySpan<byte> header, [NotNullWhen(true)] out IImageFormat? format)
+    {
+        format = this.IsSupportedFileFormat(header) ? WebpFormat.Instance : null;
+        return format != null;
+    }
 
     private bool IsSupportedFileFormat(ReadOnlySpan<byte> header)
         => header.Length >= this.HeaderSize && IsRiffContainer(header) && IsWebpFile(header);

src/ImageSharp/Image.Decode.cs

@@ -82,8 +82,7 @@ private static IImageFormat InternalDetectFormat(Configuration configuration, St
         {
             if (formatDetector.HeaderSize <= headerSize)
             {
-                IImageFormat attemptFormat = formatDetector.DetectFormat(headersBuffer);
-                if (attemptFormat != null)
+                if (formatDetector.TryDetectFormat(headersBuffer, out IImageFormat attemptFormat))
                 {
                     format = attemptFormat;
                 }

src/ImageSharp/Image.FromBytes.cs

@@ -1,7 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
+using System.Diagnostics.CodeAnalysis;
 using SixLabors.ImageSharp.Formats;
 using SixLabors.ImageSharp.PixelFormats;
 
@@ -16,39 +16,41 @@ public abstract partial class Image
     /// By reading the header on the provided byte span this calculates the images format.
     /// </summary>
     /// <param name="data">The byte span containing encoded image data to read the header from.</param>
-    /// <returns>The format or null if none found.</returns>
-    public static IImageFormat DetectFormat(ReadOnlySpan<byte> data)
-        => DetectFormat(DecoderOptions.Default, data);
+    /// <param name="format">The format or null if none found.</param>
+    /// <returns>returns true when format was detected otherwise false.</returns>
+    public static bool TryDetectFormat(ReadOnlySpan<byte> data, [NotNullWhen(true)] out IImageFormat? format)
+        => TryDetectFormat(DecoderOptions.Default, data, out format);
 
     /// <summary>
     /// By reading the header on the provided byte span this calculates the images format.
     /// </summary>
     /// <param name="options">The general decoder options.</param>
     /// <param name="data">The byte span containing encoded image data to read the header from.</param>
+    /// <param name="format">The mime type or null if none found.</param>
     /// <exception cref="ArgumentNullException">The options are null.</exception>
-    /// <returns>The mime type or null if none found.</returns>
-    public static IImageFormat DetectFormat(DecoderOptions options, ReadOnlySpan<byte> data)
+    /// <returns>returns true when format was detected otherwise false.</returns>
+    public static bool TryDetectFormat(DecoderOptions options, ReadOnlySpan<byte> data, [NotNullWhen(true)] out IImageFormat? format)
     {
         Guard.NotNull(options, nameof(options.Configuration));
 
         Configuration configuration = options.Configuration;
         int maxHeaderSize = configuration.MaxHeaderSize;
         if (maxHeaderSize <= 0)
         {
-            return null;
+            format = null;
+            return false;
         }
 
         foreach (IImageFormatDetector detector in configuration.ImageFormatsManager.FormatDetectors)
         {
-            IImageFormat f = detector.DetectFormat(data);
-
-            if (f != null)
+            if (detector.TryDetectFormat(data, out format))
             {
-                return f;
+                return true;
             }
         }
 
-        return default;
+        format = default;
+        return false;
     }
 
     /// <summary>