StbImageSharp

You can include StbImageSharp in your project using either NuGet or as a Git submodule.

Option 1: NuGet

Install via the NuGet package manager.

Option 2: Git Submodule

1. Add the submodule: git submodule add https://github.com/StbSharp/StbImageSharp.git
2. Choose one of the following integration methods:
   • Add src/StbImageSharp.csproj directly to your solution.
   • Include the .cs files from the src folder directly in your project. If you choose this method, you may want to add the STBSHARP_INTERNAL build compilation symbol to your project to keep StbImageSharp classes internal.

To convert ImageResult bytes to a WinForms Bitmap, you may need to manually convert the pixel format (e.g., from RGBA to BGRA) before copying the data using Marshal.Copy and BitmapData.

byte[] data = image.Data;
// Convert rgba to bgra
for (int i = 0; i < x*y; ++i)
{
	byte r = data[i*4];
	byte g = data[i*4 + 1];
	byte b = data[i*4 + 2];
	byte a = data[i*4 + 3];

	data[i*4] = b;
	data[i*4 + 1] = g;
	data[i*4 + 2] = r;
	data[i*4 + 3] = a;
}

// Create Bitmap
Bitmap bmp = new Bitmap(_loadedImage.Width, _loadedImage.Height, PixelFormat.Format32bppArgb);
BitmapData bmpData = bmp.LockBits(new Rectangle(0, 0, _loadedImage.Width, _loadedImage.Height), ImageLockMode.WriteOnly, bmp.PixelFormat);

Marshal.Copy(data, 0, bmpData.Scan0, bmpData.Stride*bmp.Height);
bmp.UnlockBits(bmpData);

To use a loaded ImageResult in a MonoGame application, create a new Texture2D with the image's dimensions and set its data using image.Data.

Texture2D texture = new Texture2D(GraphicsDevice, image.Width, image.Height, false, SurfaceFormat.Color);
texture.SetData(image.Data);

StbImageSharp provides utility classes to wrap the complex raw pointer API. The ImageResult class is the primary way to load standard image formats (JPG, PNG, BMP, TGA, PSD, GIF).

• ImageResult.FromStream(stream, colorComponents): Loads an image from a Stream.
• ImageResult.FromMemory(buffer, colorComponents): Loads an image from a byte[] array.

Both methods will throw an exception if the image loading fails. You should specify the desired color components using ColorComponents (e.g., ColorComponents.RedGreenBlueAlpha).

// From Stream
using(var stream = File.OpenRead(path))
{
  ImageResult image = ImageResult.FromStream(stream, ColorComponents.RedGreenBlueAlpha);
}

// From Memory
byte[] buffer = File.ReadAllBytes(path);
ImageResult image = ImageResult.FromMemory(buffer, ColorComponents.RedGreenBlueAlpha);

To handle animated GIFs, use ImageResult.AnimatedGifFramesFromStream(stream). This returns an enumerable of AnimatedFrameResult objects, allowing you to iterate through every frame and its associated delay.

foreach(AnimatedFrameResult frame in ImageResult.AnimatedGifFramesFromStream(stream))
{
    // Do something with a frame
}

Use the ImageInfo class to retrieve image metadata (width, height, color components, etc.) without fully decoding the pixel data. ImageInfo.FromStream(stream) returns null if the image type is not supported.

ImageInfo? info = ImageInfo.FromStream(imageStream);

To handle animated formats like GIFs, use ImageResult.AnimatedGifFramesFromStream. This returns an IEnumerable<AnimatedFrameResult>, allowing you to iterate through each frame of the animation.

using StbImageSharp;
using System.IO;

// ...
using (var stream = File.OpenRead("animation.gif"))
{
    var frames = ImageResult.AnimatedGifFramesFromStream(stream, ColorComponents.Rgba);
    foreach (var frame in frames)
    {
        // Process each AnimatedFrameResult
    }
}

Use ImageResult.FromStream to decode an image from a System.IO.Stream. You can optionally specify the requiredComponents to request a specific color format (e.g., RGBA).

using StbImageSharp;
using System.IO;

// ...
using (var stream = File.OpenRead("image.png"))
{
    ImageResult image = ImageResult.FromStream(stream, ColorComponents.Rgba);
    // Access image.Data, image.Width, image.Height, etc.
}

Use ImageResult.FromMemory to decode an image directly from a byte[]. This is a convenience wrapper around FromStream using a MemoryStream.

using StbImageSharp;

// ...
byte[] fileBytes = File.ReadAllBytes("image.jpg");
ImageResult image = ImageResult.FromMemory(fileBytes, ColorComponents.Rgb);