optimize code, fix typo in readme

README.md

@@ -18,7 +18,7 @@ PM> Install-Package ImageSharp.Community.Formats.Pdf
 using System.IO;
 
 using SixLabors.ImageSharp;
-using SixLabors.ImageSharp.Formats.Jpeg;
+using SixLabors.ImageSharp.Formats.Png;
 using SixLabors.ImageSharp.Processing;
 using ImageSharpCommunity.Formats.Pdf;
 

src/ImageSharpCommunity.Formats.Pdf/ImageSharpCommunity.Formats.Pdf.csproj

@@ -20,7 +20,7 @@
 		<RepositoryUrl>https://github.com/skttl/ImageSharpCommunity.Formats.Pdf</RepositoryUrl>
 		<RootNamespace>ImageSharpCommunity.Formats.Pdf</RootNamespace>
 		<Title>PDF Decoder for ImageSharp</Title>
-		<Version>0.1.0</Version>
+		<Version>0.2.0</Version>
 	</PropertyGroup>
 
 	<ItemGroup>

src/ImageSharpCommunity.Formats.Pdf/PdfConfigurationModule.cs

@@ -1,15 +1,11 @@
-using SixLabors.ImageSharp;
-using SixLabors.ImageSharp.Formats;
+namespace ImageSharpCommunity.Formats.Pdf;
 
-namespace ImageSharpCommunity.Formats.Pdf
+public sealed class PdfConfigurationModule : IImageFormatConfigurationModule
 {
-    public sealed class PdfConfigurationModule : IImageFormatConfigurationModule
+    public void Configure(Configuration configuration)
     {
-        public void Configure(Configuration configuration)
-        {
-            configuration.ImageFormatsManager.SetDecoder(PdfFormat.Instance, PdfDecoder.Instance);
-            configuration.ImageFormatsManager.SetEncoder(PdfFormat.Instance, new PdfEncoder());
-            configuration.ImageFormatsManager.AddImageFormatDetector(new PdfFormatDetector());
-        }
+        configuration.ImageFormatsManager.SetDecoder(PdfFormat.Instance, PdfDecoder.Instance);
+        configuration.ImageFormatsManager.SetEncoder(PdfFormat.Instance, new PdfEncoder());
+        configuration.ImageFormatsManager.AddImageFormatDetector(new PdfFormatDetector());
     }
 }

src/ImageSharpCommunity.Formats.Pdf/PdfDecoder.cs

@@ -1,73 +1,59 @@
-using PdfLibCore;
-using SixLabors.ImageSharp;
-using SixLabors.ImageSharp.Formats;
-using SixLabors.ImageSharp.PixelFormats;
+namespace ImageSharpCommunity.Formats.Pdf;
 
-namespace ImageSharpCommunity.Formats.Pdf
+public class PdfDecoder : SpecializedImageDecoder<PdfDecoderOptions>
 {
-    public class PdfDecoder : SpecializedImageDecoder<PdfDecoderOptions>
+    private PdfDecoder()
     {
-        private PdfDecoder()
-        {
-        }
-
-        /// <summary>
-        /// Gets the current instance.
-        /// </summary>
-        public static PdfDecoder Instance { get; } = new PdfDecoder();
-
-        protected override PdfDecoderOptions CreateDefaultSpecializedOptions(DecoderOptions options) => new() { GeneralOptions = options };
-
-        protected override Image<TPixel> Decode<TPixel>(PdfDecoderOptions options, Stream stream, CancellationToken cancellationToken)
-        {
-            ArgumentNullException.ThrowIfNull(options, nameof(options));
-            ArgumentNullException.ThrowIfNull(stream, nameof(stream));
-
-            using var pdfDocument = new PdfDocument(stream);
-            var page = pdfDocument?.Pages?.FirstOrDefault();
+    }
 
-            TryGetWidthAndHeight(page, out var width, out var height);
+    /// <summary>
+    /// Gets the current instance.
+    /// </summary>
+    public static PdfDecoder Instance { get; } = new PdfDecoder();
 
-            ArgumentNullException.ThrowIfNull(page, nameof(page));
+    protected override PdfDecoderOptions CreateDefaultSpecializedOptions(DecoderOptions options) => new() { GeneralOptions = options };
 
-            using var bitmap = new PdfiumBitmap(width, height, true);
-            page.Render(bitmap, PdfLibCore.Enums.PageOrientations.Normal, PdfLibCore.Enums.RenderingFlags.LcdText);
+    protected override Image<TPixel> Decode<TPixel>(PdfDecoderOptions options, Stream stream, CancellationToken cancellationToken)
+    {
+        ArgumentNullException.ThrowIfNull(options, nameof(options));
+        ArgumentNullException.ThrowIfNull(stream, nameof(stream));
 
-            var image = Image.Load<TPixel>(bitmap.AsBmpStream());
+        using var pdfDocument = new PdfDocument(stream);
+        var firstPageOfPdf = pdfDocument?.Pages?.FirstOrDefault();
+        ArgumentNullException.ThrowIfNull(firstPageOfPdf, nameof(firstPageOfPdf));
 
-            ScaleToTargetSize(options.GeneralOptions, image);
+        var (width, height) = GetDimensions(firstPageOfPdf);
 
-            return image;
-        }
+        using var bitmap = new PdfiumBitmap(width, height, true);
+        firstPageOfPdf.Render(bitmap, PdfLibCore.Enums.PageOrientations.Normal, PdfLibCore.Enums.RenderingFlags.LcdText);
 
-        protected override Image Decode(PdfDecoderOptions options, Stream stream, CancellationToken cancellationToken) => Decode<Rgba32>(options, stream, cancellationToken);
+        using var bmpStream = bitmap.AsBmpStream();
+        var image = Image.Load<TPixel>(bmpStream);
 
-        protected override ImageInfo Identify(DecoderOptions options, Stream stream, CancellationToken cancellationToken)
-        {
-            ArgumentNullException.ThrowIfNull(options, nameof(options));
-            ArgumentNullException.ThrowIfNull(stream, nameof(stream));
+        ScaleToTargetSize(options.GeneralOptions, image);
 
-            using var pdfDocument = new PdfDocument(stream);
-            var page = pdfDocument?.Pages?.FirstOrDefault();
-            TryGetWidthAndHeight(page, out int width, out int height);
+        return image;
+    }
 
-            return new ImageInfo(new PixelTypeInfo(4), new(width, height), null);
-        }
+    protected override Image Decode(PdfDecoderOptions options, Stream stream, CancellationToken cancellationToken) => Decode<Rgba32>(options, stream, cancellationToken);
 
-        private bool TryGetWidthAndHeight(PdfPage? page, out int width, out int height)
-        {
-            ArgumentNullException.ThrowIfNull(page, nameof(page));
+    protected override ImageInfo Identify(DecoderOptions options, Stream stream, CancellationToken cancellationToken)
+    {
+        ArgumentNullException.ThrowIfNull(options, nameof(options));
+        ArgumentNullException.ThrowIfNull(stream, nameof(stream));
 
-            var w = page.Size.Width;
-            w = w != 0 ? w / 72 * 144D : 0;
+        using var pdfDocument = new PdfDocument(stream);
+        var firstPageOfPdf = pdfDocument?.Pages?.FirstOrDefault();
+        ArgumentNullException.ThrowIfNull(firstPageOfPdf, nameof(firstPageOfPdf));
 
-            var h = page.Size.Height;
-            h = h != 0 ? h / 72 * 144D : 0;
+        var (width, height) = GetDimensions(firstPageOfPdf);
 
-            width = (int)w;
-            height = (int)h;
+        return new ImageInfo(new PixelTypeInfo(4), new(width, height), null);
+    }
 
-            return true;
-        }
+    private static (int width, int height) GetDimensions(PdfPage page)
+    {
+        ArgumentNullException.ThrowIfNull(page, nameof(page));
+        return ((int)page.Width, (int)page.Height);
     }
 }

src/ImageSharpCommunity.Formats.Pdf/PdfDecoderOptions.cs

@@ -1,10 +1,7 @@
-using SixLabors.ImageSharp.Formats;
+namespace ImageSharpCommunity.Formats.Pdf;
 
-namespace ImageSharpCommunity.Formats.Pdf
+public sealed class PdfDecoderOptions : ISpecializedDecoderOptions
 {
-    public sealed class PdfDecoderOptions : ISpecializedDecoderOptions
-    {
-        /// <inheritdoc/>
-        public DecoderOptions GeneralOptions { get; init; } = new();
-    }
+    /// <inheritdoc/>
+    public DecoderOptions GeneralOptions { get; init; } = new();
 }

src/ImageSharpCommunity.Formats.Pdf/PdfEncoder.cs

@@ -1,13 +1,9 @@
-using SixLabors.ImageSharp;
-using SixLabors.ImageSharp.Formats;
+namespace ImageSharpCommunity.Formats.Pdf;
 
-namespace ImageSharpCommunity.Formats.Pdf
+public class PdfEncoder : ImageEncoder
 {
-    public class PdfEncoder : ImageEncoder
+    protected override void Encode<TPixel>(Image<TPixel> image, Stream stream, CancellationToken cancellationToken)
     {
-        protected override void Encode<TPixel>(Image<TPixel> image, Stream stream, CancellationToken cancellationToken)
-        {
-            throw new NotImplementedException();
-        }
+        throw new NotSupportedException("PDF encoding is not supported");
     }
 }

src/ImageSharpCommunity.Formats.Pdf/PdfFormat.cs

@@ -1,23 +1,33 @@
-using SixLabors.ImageSharp.Formats;
+namespace ImageSharpCommunity.Formats.Pdf;
 
-namespace ImageSharpCommunity.Formats.Pdf
+public sealed class PdfFormat : IImageFormat
 {
-    public sealed class PdfFormat : IImageFormat
+    private PdfFormat()
     {
-        private PdfFormat()
-        {
-        }
+    }
 
-        /// <summary>
-        /// Gets the current instance.
-        /// </summary>
-        public static PdfFormat Instance { get; } = new();
-        public string Name => "PDF";
+    /// <summary>
+    /// Gets the current instance of the <see cref="PdfFormat"/>.
+    /// </summary>
+    public static PdfFormat Instance { get; } = new();
 
-        public string DefaultMimeType => "application/pdf";
+    /// <summary>
+    /// Gets the name of the image format.
+    /// </summary>
+    public string Name => "PDF";
 
-        public IEnumerable<string> MimeTypes => new[] { "application/pdf" };
+    /// <summary>
+    /// Gets the default MIME type of the image format.
+    /// </summary>
+    public string DefaultMimeType => "application/pdf";
 
-        public IEnumerable<string> FileExtensions => new[] { "pdf" };
-    }
+    /// <summary>
+    /// Gets the MIME types associated with the image format.
+    /// </summary>
+    public IEnumerable<string> MimeTypes { get; } = ImmutableArray.Create("application/pdf");
+
+    /// <summary>
+    /// Gets the file extensions associated with the image format.
+    /// </summary>
+    public IEnumerable<string> FileExtensions { get; } = ImmutableArray.Create("pdf");
 }

src/ImageSharpCommunity.Formats.Pdf/PdfFormatDetector.cs

@@ -1,36 +1,21 @@
-using SixLabors.ImageSharp.Formats;
-using System.Diagnostics.CodeAnalysis;
+namespace ImageSharpCommunity.Formats.Pdf;
 
-namespace ImageSharpCommunity.Formats.Pdf
+public class PdfFormatDetector : IImageFormatDetector
 {
-    public class PdfFormatDetector : IImageFormatDetector
-    {
-        public int HeaderSize => 16;
-
-        public bool TryDetectFormat(ReadOnlySpan<byte> header, [NotNullWhen(true)] out IImageFormat? format)
-        {
-            format = IsPDFFileFormat(header) ? PdfFormat.Instance : null;
-
-            return format != null;
-        }
-
-        private bool IsPDFFileFormat(ReadOnlySpan<byte> header)
-        {
-            if (header.Length >= 4)
-            {
-                var first4 = header[..4];
+    public int HeaderSize => 16;
 
-                var shouldMatch = new byte[]{
-                    0x25,   // %
-                    0x50,   // P
-                    0x44,   // D
-                    0x46,   // F
-                };
-
-                return first4.SequenceEqual(shouldMatch);
-            }
+    public bool TryDetectFormat(ReadOnlySpan<byte> header, [NotNullWhen(true)] out IImageFormat? format)
+    {
+        format = IsPDFFileFormat(header) ? PdfFormat.Instance : null;
+        return format != null;
+    }
 
-            return false;
-        }
+    private static bool IsPDFFileFormat(ReadOnlySpan<byte> header)
+    {
+        return header.Length >= 4 &&
+               header[0] == 0x25 && // %
+               header[1] == 0x50 && // P
+               header[2] == 0x44 && // D
+               header[3] == 0x46;  // F
     }
 }

src/ImageSharpCommunity.Formats.Pdf/Usings.cs

@@ -0,0 +1,6 @@
+global using PdfLibCore;
+global using SixLabors.ImageSharp;
+global using SixLabors.ImageSharp.Formats;
+global using SixLabors.ImageSharp.PixelFormats;
+global using System.Collections.Immutable;
+global using System.Diagnostics.CodeAnalysis;