C#•2y ago

❔ supporting .ico files on non-windows platforms

I searched the web for how to convert a .ico file into a bmp or png or basically anything else, but every example I found used System.Drawing libs that are only available on windows. A lot of web pages still use .ico files as favicons as an anachronistic backwards compatibility thing for Internet Explorer. Does anyone know of a way to take a .ico file in memory and convert it to a better supported format?

5 Replies

Angius•2y ago

ImageSharp maybe? If not, just find some ImageMagick wrapper, or even invoke it directly

duncan3052OP•2y ago

looking at magick.net, I will post here if it works as a solution

private byte[] ConvertIcoToPng(byte[] bytes)
{
    string tempFile = Path.Combine(Path.GetTempPath(), Guid.NewGuid() + ".ico");
    File.WriteAllBytes(tempFile, bytes);
    
    using MagickImage image = new (tempFile);
    image.Format = MagickFormat.Png;
    File.Delete(tempFile);
    return image.ToByteArray();
}

private byte[] ConvertIcoToPng(byte[] bytes)
{
    string tempFile = Path.Combine(Path.GetTempPath(), Guid.NewGuid() + ".ico");
    File.WriteAllBytes(tempFile, bytes);
    
    using MagickImage image = new (tempFile);
    image.Format = MagickFormat.Png;
    File.Delete(tempFile);
    return image.ToByteArray();
}

duncan3052OP•2y ago

Its a pity I have to use a temp file, imagemagick can read a byte array but for some reason it fails in this case. Still this is a nicer and cleaner solution than any I found using the System.Drawing libs. I might use this lib (https://github.com/dlemstra/Magick.NET) for all my image needs in future.

GitHub

GitHub - dlemstra/Magick.NET: The .NET library for ImageMagick

The .NET library for ImageMagick. Contribute to dlemstra/Magick.NET development by creating an account on GitHub.

duncan3052OP•2y ago

Thanks for the suggestion. ah I sorted it, ico has no file type identifier at the beginning of the file so without the file suffix imagemagick cant identify what format it is in. The correct code is:

private static byte[] ConvertIcoToPng(byte[] bytes)
{
    using MagickImage image = new (bytes, MagickFormat.Ico);
    image.Format = MagickFormat.Png;
    return image.ToByteArray();
}

private static byte[] ConvertIcoToPng(byte[] bytes)
{
    using MagickImage image = new (bytes, MagickFormat.Ico);
    image.Format = MagickFormat.Png;
    return image.ToByteArray();
}

Accord•2y ago

Was this issue resolved? If so, run /close - otherwise I will mark this as stale and this post will be archived until there is new activity.

Gaming

Programming

❔ supporting .ico files on non-windows platforms