Create image object from base64 and save as file

[HypeillingerChillinger]

How can I create an ImageSharp Image object from a base64 string?
I only found ImageExtensions.ToBase64String but not sth. like FromBase64String

Use a MemoryStream with Image.Load?

[JimBobSquarePants]

You’d have to get the bytes from the string and pass to a stream.

[antonfirsov]

byte[] data = Convert.FromBase64String(base64String);
using var image = Image.Load(data);

[tocsoft]

that wont work if its a data uri (which our ToBase64String returns)... you would need to strip the header portion first.

[HypeillingerChillinger]

Great, thanks.
May be a Image.LoadFromBase64(string base64) would be handy.

[5pHiNxX]

I wrote a small helper class to load an image from base64 string (as return by ToBase64String).

public partial class ImageSharpHelper
{
    [GeneratedRegex(@"^data:(image\/[a-zA-Z]+);base64,(.*)$")]
    private static partial Regex Base64Regex();

    public static Image FromBase64String(string base64String)
    {
        var decodedString = Uri.UnescapeDataString(base64String);
        var match = Base64Regex().Match(decodedString);

        if (!match.Success)
        {
            throw new ArgumentException("The current image is not in expected format.");
        }

        /* var mimeType = match.Groups[1].Value; */
        var base64Data = match.Groups[2].Value;

        var bytes = Convert.FromBase64String(base64Data);
        return Image.Load(bytes);
    }
}

Usage:

using var loadedImage = ImageSharpHelper.FromBase64String(base64ImageString);