📷 A modern, cross-platform, 2D Graphics library for .NET
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// Copyright (c) Six Labors and contributors.
// Licensed under the Apache License, Version 2.0.
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using SixLabors.ImageSharp.Formats;
using SixLabors.ImageSharp.PixelFormats;
namespace SixLabors.ImageSharp
{
/// <content>
/// Adds static methods allowing the creation of new image from a given stream.
/// </content>
public static partial class Image
{
/// <summary>
/// By reading the header on the provided stream this calculates the images mime type.
/// </summary>
/// <param name="stream">The image stream to read the header from.</param>
/// <returns>The mime type or null if none found.</returns>
public static IImageFormat DetectFormat(Stream stream)
{
return DetectFormat(null, stream);
}
/// <summary>
/// By reading the header on the provided stream this calculates the images mime type.
/// </summary>
/// <param name="config">The configuration.</param>
/// <param name="stream">The image stream to read the header from.</param>
/// <returns>The mime type or null if none found.</returns>
public static IImageFormat DetectFormat(Configuration config, Stream stream)
{
return WithSeekableStream(stream, s => InternalDetectFormat(s, config ?? Configuration.Default));
}
/// <summary>
/// By reading the header on the provided stream this reads the raw image information.
/// </summary>
/// <param name="stream">The image stream to read the header from.</param>
/// <exception cref="NotSupportedException">
/// Thrown if the stream is not readable nor seekable.
/// </exception>
/// <returns>
/// The <see cref="IImageInfo"/> or null if suitable info detector not found.
/// </returns>
public static IImageInfo Identify(Stream stream)
{
return Identify(null, stream);
}
/// <summary>
/// Reads the raw image information from the specified stream without fully decoding it.
/// </summary>
/// <param name="config">The configuration.</param>
/// <param name="stream">The image stream to read the information from.</param>
/// <exception cref="NotSupportedException">
/// Thrown if the stream is not readable nor seekable.
/// </exception>
/// <returns>
/// The <see cref="IImageInfo"/> or null if suitable info detector is not found.
/// </returns>
public static IImageInfo Identify(Configuration config, Stream stream)
{
return WithSeekableStream(stream, s => InternalIdentity(s, config ?? Configuration.Default));
}
/// <summary>
/// Create a new instance of the <see cref="Image{Rgba32}"/> class from the given stream.
/// </summary>
/// <param name="stream">The stream containing image information.</param>
/// <param name="format">the mime type of the decoded image.</param>
/// <exception cref="NotSupportedException">
/// Thrown if the stream is not readable nor seekable.
/// </exception>
/// <returns>A new <see cref="Image{Rgba32}"/>.</returns>>
public static Image<Rgba32> Load(Stream stream, out IImageFormat format) => Load<Rgba32>(stream, out format);
/// <summary>
/// Create a new instance of the <see cref="Image{Rgba32}"/> class from the given stream.
/// </summary>
/// <param name="stream">The stream containing image information.</param>
/// <exception cref="NotSupportedException">
/// Thrown if the stream is not readable nor seekable.
/// </exception>
/// <returns>A new <see cref="Image{Rgba32}"/>.</returns>>
public static Image<Rgba32> Load(Stream stream) => Load<Rgba32>(stream);
/// <summary>
/// Create a new instance of the <see cref="Image{Rgba32}"/> class from the given stream.
/// </summary>
/// <param name="stream">The stream containing image information.</param>
/// <param name="decoder">The decoder.</param>
/// <exception cref="NotSupportedException">
/// Thrown if the stream is not readable nor seekable.
/// </exception>
/// <returns>A new <see cref="Image{Rgba32}"/>.</returns>>
public static Image<Rgba32> Load(Stream stream, IImageDecoder decoder) => Load<Rgba32>(stream, decoder);
/// <summary>
/// Create a new instance of the <see cref="Image{Rgba32}"/> class from the given stream.
/// </summary>
/// <param name="config">The config for the decoder.</param>
/// <param name="stream">The stream containing image information.</param>
/// <exception cref="NotSupportedException">
/// Thrown if the stream is not readable nor seekable.
/// </exception>
/// <returns>A new <see cref="Image{Rgba32}"/>.</returns>>
public static Image<Rgba32> Load(Configuration config, Stream stream) => Load<Rgba32>(config, stream);
/// <summary>
/// Create a new instance of the <see cref="Image{Rgba32}"/> class from the given stream.
/// </summary>
/// <param name="config">The config for the decoder.</param>
/// <param name="stream">The stream containing image information.</param>
/// <param name="format">the mime type of the decoded image.</param>
/// <exception cref="NotSupportedException">
/// Thrown if the stream is not readable nor seekable.
/// </exception>
/// <returns>A new <see cref="Image{Rgba32}"/>.</returns>>
public static Image<Rgba32> Load(Configuration config, Stream stream, out IImageFormat format) => Load<Rgba32>(config, stream, out format);
/// <summary>
/// Create a new instance of the <see cref="Image{TPixel}"/> class from the given stream.
/// </summary>
/// <param name="stream">The stream containing image information.</param>
/// <exception cref="NotSupportedException">
/// Thrown if the stream is not readable nor seekable.
/// </exception>
/// <typeparam name="TPixel">The pixel format.</typeparam>
/// <returns>A new <see cref="Image{TPixel}"/>.</returns>>
public static Image<TPixel> Load<TPixel>(Stream stream)
where TPixel : struct, IPixel<TPixel>
{
return Load<TPixel>(null, stream);
}
/// <summary>
/// Create a new instance of the <see cref="Image{TPixel}"/> class from the given stream.
/// </summary>
/// <param name="stream">The stream containing image information.</param>
/// <param name="format">the mime type of the decoded image.</param>
/// <exception cref="NotSupportedException">
/// Thrown if the stream is not readable nor seekable.
/// </exception>
/// <typeparam name="TPixel">The pixel format.</typeparam>
/// <returns>A new <see cref="Image{TPixel}"/>.</returns>>
public static Image<TPixel> Load<TPixel>(Stream stream, out IImageFormat format)
where TPixel : struct, IPixel<TPixel>
{
return Load<TPixel>(null, stream, out format);
}
/// <summary>
/// Create a new instance of the <see cref="Image{TPixel}"/> class from the given stream.
/// </summary>
/// <param name="stream">The stream containing image information.</param>
/// <param name="decoder">The decoder.</param>
/// <exception cref="NotSupportedException">
/// Thrown if the stream is not readable nor seekable.
/// </exception>
/// <typeparam name="TPixel">The pixel format.</typeparam>
/// <returns>A new <see cref="Image{TPixel}"/>.</returns>>
public static Image<TPixel> Load<TPixel>(Stream stream, IImageDecoder decoder)
where TPixel : struct, IPixel<TPixel>
{
return WithSeekableStream(stream, s => decoder.Decode<TPixel>(Configuration.Default, s));
}
/// <summary>
/// Create a new instance of the <see cref="Image{TPixel}"/> class from the given stream.
/// </summary>
/// <param name="config">The Configuration.</param>
/// <param name="stream">The stream containing image information.</param>
/// <param name="decoder">The decoder.</param>
/// <exception cref="NotSupportedException">
/// Thrown if the stream is not readable nor seekable.
/// </exception>
/// <typeparam name="TPixel">The pixel format.</typeparam>
/// <returns>A new <see cref="Image{TPixel}"/>.</returns>>
public static Image<TPixel> Load<TPixel>(Configuration config, Stream stream, IImageDecoder decoder)
where TPixel : struct, IPixel<TPixel>
{
return WithSeekableStream(stream, s => decoder.Decode<TPixel>(config, s));
}
/// <summary>
/// Create a new instance of the <see cref="Image{TPixel}"/> class from the given stream.
/// </summary>
/// <param name="config">The configuration options.</param>
/// <param name="stream">The stream containing image information.</param>
/// <exception cref="NotSupportedException">
/// Thrown if the stream is not readable nor seekable.
/// </exception>
/// <typeparam name="TPixel">The pixel format.</typeparam>
/// <returns>A new <see cref="Image{TPixel}"/>.</returns>>
public static Image<TPixel> Load<TPixel>(Configuration config, Stream stream)
where TPixel : struct, IPixel<TPixel>
{
return Load<TPixel>(config, stream, out var _);
}
/// <summary>
/// Create a new instance of the <see cref="Image{TPixel}"/> class from the given stream.
/// </summary>
/// <param name="config">The configuration options.</param>
/// <param name="stream">The stream containing image information.</param>
/// <param name="format">the mime type of the decoded image.</param>
/// <exception cref="NotSupportedException">
/// Thrown if the stream is not readable nor seekable.
/// </exception>
/// <typeparam name="TPixel">The pixel format.</typeparam>
/// <returns>A new <see cref="Image{TPixel}"/>.</returns>>
public static Image<TPixel> Load<TPixel>(Configuration config, Stream stream, out IImageFormat format)
where TPixel : struct, IPixel<TPixel>
{
config = config ?? Configuration.Default;
(Image<TPixel> img, IImageFormat format) data = WithSeekableStream(stream, s => Decode<TPixel>(s, config));
format = data.format;
if (data.img != null)
{
return data.img;
}
var stringBuilder = new StringBuilder();
stringBuilder.AppendLine("Image cannot be loaded. Available decoders:");
foreach (KeyValuePair<IImageFormat, IImageDecoder> val in config.ImageDecoders)
{
stringBuilder.AppendLine($" - {val.Key.Name} : {val.Value.GetType().Name}");
}
throw new NotSupportedException(stringBuilder.ToString());
}
private static T WithSeekableStream<T>(Stream stream, Func<Stream, T> action)
{
if (!stream.CanRead)
{
throw new NotSupportedException("Cannot read from the stream.");
}
if (stream.CanSeek)
{
return action(stream);
}
// We want to be able to load images from things like HttpContext.Request.Body
using (var memoryStream = new MemoryStream())
{
stream.CopyTo(memoryStream);
memoryStream.Position = 0;
return action(memoryStream);
}
}
}
}