Image to byte[], Convert and ConvertBack

Question

I have a service that converts images stored on a website to byte array

                HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create("URLTOIMAGE");
                myRequest.Method = "GET";
                HttpWebResponse myResponse = (HttpWebResponse)myRequest.GetResponse();
                Bitmap bmp = new Bitmap(myResponse.GetResponseStream());
                myResponse.Close();
                ms = new MemoryStream();
                bmp.Save(ms, ImageFormat.Bmp);

This code returns a byte array that I store in a database (SQL Azure). In my Windows Phone application, I try to convert this byte array to display it on my page.

public class BytesToImageConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        BitmapImage empImage = new BitmapImage();
        empImage.SetSource(new MemoryStream((Byte[])value));
        return empImage;
    }

    public object ConvertBack(object value, Type targetType, object parameter,
                                System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

The byte array is well received by the application, but an exception is thrown when I try to do a SetSource.

empImage.SetSource(new MemoryStream((Byte[])value));
=> "Exception was unhandled", The request is not supported

Can you help me? Thx

It's JPEG => byte[] and byte[] to BitmapImage (for Imagesource) — Julien, Mar 21 '12 at 14:28

score 3 · Accepted Answer · answered Mar 21 '12 at 15:34

This code works :

public class BytesToImageConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        MemoryStream stream = new MemoryStream((Byte[])value);
        WriteableBitmap bmp = new WriteableBitmap(173, 173);
        bmp.LoadJpeg(stream);
        return bmp;
    }

    public object ConvertBack(object value, Type targetType, object parameter,
                                System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

Thank you everyone :)

you can also check the solution here that uses a more dynamic approach for the picture size: http://stackoverflow.com/questions/9948252/byte-array-to-writeablebitmap-image-ivalueconverter-for-wp7/9949432#9949432 — Michael, Mar 30 '12 at 19:44

score 2 · Answer 2 · edited May 23 '17 at 12:32

2

these questions have already been answered on stackoverflow
for the image to a byte[] try this
and for the byte[] to image try this

edited May 23 '17 at 12:32

Community

1
1

answered Mar 21 '12 at 14:20

harryovers

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I use the same code (use of memeorystream), but it does not work. – Julien Mar 21 '12 at 14:24

score 1 · Answer 3 · answered Jan 10 '13 at 11:25

private ImageSource GetPhoto(byte[] bytearr)
{
   if (bytearr != null)
   {
      BitmapImage image = new BitmapImage();

      InMemoryRandomAccessStream ms = new InMemoryRandomAccessStream();
      ms.AsStreamForWrite().Write(bytearr, 0, bytearr.Length);
      ms.Seek(0);

      image.SetSource(ms);
      ImageSource src = image;

      return src;
   }
   else
      return null;
}

score 0 · Answer 4 · answered Mar 20 '17 at 10:29

For my UWP app i use the following IValueConverter to convert a byte array to a bindable object for an <Image Source={Binding} />

internal class ByteImageSourceConverter : IValueConverter
{
    object IValueConverter.Convert(object value, Type targetType, object parameter, string language)
    {
        if (value == null)
            return null;
        return ByteToImage((byte[])value);
    }

    object IValueConverter.ConvertBack(object value, Type targetType, object parameter, string language)
    {
        throw new NotImplementedException();
    }

    static ImageSource ByteToImage(byte[] imageBytes)
    {
        BitmapImage image = new BitmapImage();
        image.SetSource(imageBytes.ConvertToInMemoryRandomAcessStream());
        ImageSource src = image;
        return src;
    }
}

internal static InMemoryRandomAccessStream ConvertToInMemoryRandomAcessStream(this byte[] arr)
{
    var randomAccessStream = new InMemoryRandomAccessStream();
    randomAccessStream.WriteAsync(arr.AsBuffer());
    randomAccessStream.Seek(0);
    return randomAccessStream;
}

Excuse me for the WriteAsync in a synchronous function. For the purpose of this post I don't have the time to solve this one, but it works this way :)

Image to byte[], Convert and ConvertBack

4 Answers4

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