C# convert image data to bytes array

Question

I have a image with src = "data:image/png;base64...." .

I want to convert this image into byte array byte[] .

I have tried something like this:

string[] Base64 = ImageData.Split(new char[] { ',' });

byte[] imageBytes = System.Convert.FromBase64String(Base64[1].ToString());

What am I doing wrong here?

Answer 1

C# 8 version, without using Regex or MemoryStream :

var base64Image = "data:image/png;base64,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";

var offset = base64Image.IndexOf(',') + 1;

var imageInBytes = Convert.FromBase64String(base64Image[offset..^0]);

Answer 2

^{This was originally posted in the question itself by the OP. It was edited out of the question and into an answer.}

---

Here is how I fixed it:

var base64Data = Regex.Match(ImageData.ImageURL, @"data:image/(?<type>.+?),(?<data>.+)").Groups["data"].Value;

byte[] imageBytes = Convert.FromBase64String(base64Data);

Answer 3

I have no clue why you want to have the image as a byte-array, but think abour Memorystreams. This example is in vb.net:

Private Function GetImageByteArray(im As Image) As Byte()
    Try
        Using st As System.IO.MemoryStream = New System.IO.MemoryStream
            im.Save(st, Imaging.ImageFormat.Raw)
            Return st.ToArray
        End Using
    Finally
        GC.Collect()
    End Try
End Function


private byte[] GetImageByteArray(Image im)
{
    try
    {
        using(MemoryStream st = new MemoryStream())
        {
            im.save(st, ImageFormat.Raw);
            return st.toarray();
        }
    }
    finally
    {
        GC.Collect();
    }
}

But the described problem is more like converting data from a string into a byte-array.

image im;
using memorystream st = new memorystream(Convert.FromBase64String(data.substring(data.firstindexof(',')))
{im = image.fromstream(st);}