Sdcb.SimdCodecs.Ico 1.2.0

Prefix Reserved
.NET 10.0 This package targets .NET 10.0. The package is compatible with this framework or higher. 
dotnet add package Sdcb.SimdCodecs.Ico --version 1.2.0
                    


                    

                
NuGet\Install-Package Sdcb.SimdCodecs.Ico -Version 1.2.0
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package. 
<PackageReference Include="Sdcb.SimdCodecs.Ico" Version="1.2.0" />
For projects that support PackageReference, copy this XML node into the project file to reference the package. 
<PackageVersion Include="Sdcb.SimdCodecs.Ico" Version="1.2.0" />
                    


                            Directory.Packages.props
                        

                    

                
<PackageReference Include="Sdcb.SimdCodecs.Ico" />
                    


                            Project file
For projects that support Central Package Management (CPM), copy this XML node into the solution Directory.Packages.props file to version the package. 
paket add Sdcb.SimdCodecs.Ico --version 1.2.0
                    


                    

                
#r "nuget: Sdcb.SimdCodecs.Ico, 1.2.0"
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package. 
#:package Sdcb.SimdCodecs.Ico@1.2.0
#:package directive can be used in C# file-based apps starting in .NET 10 preview 4. Copy this into a .cs file before any lines of code to reference the package. 
#addin nuget:?package=Sdcb.SimdCodecs.Ico&version=1.2.0
                    


                            Install as a Cake Addin
                        

                    

                
#tool nuget:?package=Sdcb.SimdCodecs.Ico&version=1.2.0
                    


                            Install as a Cake Tool

Sdcb.SimdCodecs.Ico

Pure-managed Windows icon (.ico) and cursor (.cur) decoding and encoding for .NET 10, from Microsoft's documentation of the icon file. An icon is a directory of images, each a PNG stream (read and written by Sdcb.SimdCodecs.Png) or a packed DIB with an AND mask (by Sdcb.SimdCodecs.Bmp, so every DIB depth and its SIMD row kernels come along). Every image decodes to 8-bit RGBA.

using Sdcb.SimdCodecs.Ico;

byte[] data = File.ReadAllBytes("app.ico");
IcoInfo info = IcoDecoder.ReadInfo(data);       // kind, every image's size / depth / PNG-or-DIB / hotspot
IcoImage best = IcoDecoder.Decode(data);        // the largest, deepest image (info.Best)
IcoImage small = IcoDecoder.Decode(data, 0);    // any image, by directory index

Through the Sdcb.SimdCodecs facade an icon is ImageFormat.Ico and a cursor ImageFormat.Cur; TryDecode gives the largest, deepest image, and TryOpenFrames every image as a page of its own size.

Encoding

byte[] ico = IcoEncoder.Encode(
[
    new IcoFrame(rgba16, 16, 16),
    new IcoFrame(rgba32, 32, 32),
    new IcoFrame(rgba256, 256, 256),                                  // PNG
    new IcoFrame(rgba48, 48, 48, Encoding: IcoImageEncoding.Bmp8),     // 256-colour DIB
]);

byte[] cur = IcoEncoder.EncodeCursor([new IcoFrame(rgba32, 32, 32, HotspotX: 4, HotspotY: 2)]);

Each image is 1 to 256 pixels a side, in any ImagePixelFormat, stored as Png, Bmp32 (alpha, plus an AND mask from it), or Bmp24 / Bmp8 / Bmp4 / Bmp1 (transparency in the AND mask only; a palette is exact when the colours fit, otherwise Wu-quantized). Auto is PNG at 256 pixels and 32-bit BMP below: compact where icons get large, and readable everywhere else. Alpha below 128 is transparent in an AND mask, and a transparent pixel of a DIB without alpha is written black, as the mask needs to draw it.

Decisions

Case Decoded as
Which image Decode / the facade's TryDecode returns The largest by area, then the deepest, then the first
An image's size The image's own header: a directory entry's byte (0 for 256) can disagree, and is not used
An image size that runs past the end of the file Cut to the file
An image that starts inside the directory or past the end The file is refused
A DIB image Its colour bitmap and AND mask (see Sdcb.SimdCodecs.Bmp): 32-bit pixels' alpha unless all 0, otherwise the mask; without a mask, opaque. Compressed DIBs are refused
A PNG image Whatever PNG holds, converted to 8-bit RGBA; it may be larger than 256
The colour of a transparent pixel As stored (WIC agrees; ImageMagick may differ, and only alpha is compared there)

Images above 2^28 pixels are refused. Every image of a corpus of hand-built DIB icons, PNG images and every encoder layout decodes to WIC's pixels, frame for frame, and ImageMagick reads the encoder's output back exactly.

Product Compatible and additional computed target framework versions.
.NET net10.0 is compatible.  net10.0-android was computed.  net10.0-browser was computed.  net10.0-ios was computed.  net10.0-maccatalyst was computed.  net10.0-macos was computed.  net10.0-tvos was computed.  net10.0-windows was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.

NuGet packages (1)

Showing the top 1 NuGet packages that depend on Sdcb.SimdCodecs.Ico:

Package Downloads
Sdcb.SimdCodecs

Image-codec facade over the Sdcb.SimdCodecs family: sniff a byte stream's format by its magic-byte signature and dispatch to the matching decoder (PNG, JPEG, TIFF, JBIG2, JPEG 2000, WebP, GIF, BMP, ICO, CUR, QOI, PBM / PGM / PPM / PAM, PFM), returning a codec-neutral IDecodedImage (fidelity tier: native bit depth + ColorEncoding colour signalling, with a ToFloats() RGBA float32 view) or decoding zero-copy into a caller-provided 8-bit RGBA buffer (display tier, integer-sample formats). AOT-compatible.

GitHub repositories

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Version Downloads Last Updated
1.2.0 35 10/30/2026
1.1.0 35 10/30/2026